Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity.
Brunetto Gustavo,Bastos de Melo George Wellington,Terzano Roberto,Del Buono Daniele,Astolfi Stefania,Tomasi Nicola,Pii Youry,Mimmo Tanja,Cesco Stefano
Viticulture represents an important agricultural practice in many countries worldwide. Yet, the continuous use of fungicides has caused copper (Cu) accumulation in soils, which represent a major environmental and toxicological concern. Despite being an important micronutrient, Cu can be a potential toxicant at high concentrations since it may cause morphological, anatomical and physiological changes in plants, decreasing both food productivity and quality. Rhizosphere processes can, however, actively control the uptake and translocation of Cu in plants. In particular, root exudates affecting the chemical, physical and biological characteristics of the rhizosphere, might reduce the availability of Cu in the soil and hence its absorption. In addition, this review will aim at discussing the advantages and disadvantages of agronomic practices, such as liming, the use of pesticides, the application of organic matter, biochar and coal fly ashes, the inoculation with bacteria and/or mycorrhizal fungi and the intercropping, in alleviating Cu toxicity symptoms.
Grape microbiome as a reliable and persistent signature of field origin and environmental conditions in Cannonau wine production.
Mezzasalma Valerio,Sandionigi Anna,Bruni Ilaria,Bruno Antonia,Lovicu Gianni,Casiraghi Maurizio,Labra Massimo
Grape berries harbor a wide range of microbes originating from the vineyard environment, many of which are recognized for their role in the must fermentation process shaping wine quality. To better clarify the contribution of the microbiome of grape fruits during wine fermentation, we used high-throughput sequencing to identify bacterial and fungi communities associated with berries and musts of Cannonau. This is the most important cultivar-wine of Sardinia (Italy) where most vineyards are cultivated without phytochemical treatments. Results suggested that microbiomes of berries collected at four different localities share a core composition characterized by Enterobacteriales, Pseudomonadales, Bacillales, and Rhodospirillales. However, any area seems to enrich berries microbiome with peculiar microbial traits. For example, berries belonging to the biodynamic vineyards of Mamoiada were rich in Bacillales typical of manure (i.e. Lysinibacillus, Bacillus, and Sporosarcina), whereas in the Santadi locality, berries showed soil bacteria such as Pasteurellales and Bacteroidales as well as Rhodospirillales and Lactobacillales which are commonly involved in wine fermentation. In the case of fungi, the most abundant taxa were Dothioraceae, Pleosporaceae, and Saccharomycodaceae, and although the proportion of these families varied among localities, they occurred ubiquitously in all vineyards. During vinification processes performed at the same wine cellar under controlled conditions and without using any yeast starter, more than 50% of bacteria groups of berries reached musts, and each locality had its own private bacteria signature, even if Saccharomyces cerevisiae represented the most abundant fungal species. This work suggests that natural berries microbiome could be influenced by pedoclimatic and anthropologic conditions (e.g., farming management), and the fruits' microorganisms persist during the fermentation process. For these reasons, a reliable wine genotyping should include the entire holobiont (plant and all its symbionts), and bioprospecting activities on grape microbiota could lead to improved viticulture yields and wine quality.
Assessment of Cu applications in two contrasting soils-effects on soil microbial activity and the fungal community structure.
Keiblinger Katharina M,Schneider Martin,Gorfer Markus,Paumann Melanie,Deltedesco Evi,Berger Harald,Jöchlinger Lisa,Mentler Axel,Zechmeister-Boltenstern Sophie,Soja Gerhard,Zehetner Franz
Ecotoxicology (London, England)
Copper (Cu)-based fungicides have been used in viticulture to prevent downy mildew since the end of the 19th century, and are still used today to reduce fungal diseases. Consequently, Cu has built up in many vineyard soils, and it is still unclear how this affects soil functioning. The present study aimed to assess the short and medium-term effects of Cu contamination on the soil fungal community. Two contrasting agricultural soils, an acidic sandy loam and an alkaline silt loam, were used for an eco-toxicological greenhouse pot experiment. The soils were spiked with a Cu-based fungicide in seven concentrations (0-5000 mg Cu kg soil) and alfalfa was grown in the pots for 3 months. Sampling was conducted at the beginning and at the end of the study period to test Cu toxicity effects on total microbial biomass, basal respiration and enzyme activities. Fungal abundance was analysed by ergosterol at both samplings, and for the second sampling, fungal community structure was evaluated via ITS amplicon sequences. Soil microbial biomass C as well as microbial respiration rate decreased with increasing Cu concentrations, with EC ranging from 76 to 187 mg EDTA-extractable Cu kg soil. Oxidative enzymes showed a trend of increasing activity at the first sampling, but a decline in peroxidase activity was observed for the second sampling. We found remarkable Cu-induced changes in fungal community abundance (EC ranging from 9.2 to 94 mg EDTA-extractable Cu kg soil) and composition, but not in diversity. A large number of diverse fungi were able to thrive under elevated Cu concentrations, though within the order of Hypocreales several species declined. A remarkable Cu-induced change in the community composition was found, which depended on the soil properties and, hence, on Cu availability.
The ecology of the Drosophila-yeast mutualism in wineries.
Quan Allison S,Eisen Michael B
The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila.
Metagenomic Approaches to Investigate the Contribution of the Vineyard Environment to the Quality of Wine Fermentation: Potentials and Difficulties.
Stefanini Irene,Cavalieri Duccio
Frontiers in microbiology
The winemaking is a complex process that begins in the vineyard and ends at consumption moment. Recent reports have shown the relevance of microbial populations in the definition of the regional organoleptic and sensory characteristics of a wine. Metagenomic approaches, allowing the exhaustive identification of microorganisms present in complex samples, have recently played a fundamental role in the dissection of the contribution of the vineyard environment to wine fermentation. Systematic approaches have explored the impact of agronomical techniques, vineyard topologies, and climatic changes on bacterial and fungal populations found in the vineyard and in fermentations, also trying to predict or extrapolate the effects on the sensorial characteristics of the resulting wine. This review is aimed at highlighting the major technical and experimental challenges in dissecting the contribution of the vineyard and native environments microbiota to the wine fermentation process, and how metagenomic approaches can help in understanding microbial fluxes and selections across the environments and specimens related to wine fermentation.
Herbicides in vineyards reduce grapevine root mycorrhization and alter soil microorganisms and the nutrient composition in grapevine roots, leaves, xylem sap and grape juice.
Zaller Johann G,Cantelmo Clemens,Santos Gabriel Dos,Muther Sandrina,Gruber Edith,Pallua Paul,Mandl Karin,Friedrich Barbara,Hofstetter Ingrid,Schmuckenschlager Bernhard,Faber Florian
Environmental science and pollution research international
Herbicides are increasingly applied in vineyards worldwide. However, not much is known on potential side effects on soil organisms or on the nutrition of grapevines (Vitis vinifera). In an experimental vineyard in Austria, we examined the impacts of three within-row herbicide treatments (active ingredients: flazasulfuron, glufosinate, glyphosate) and mechanical weeding on grapevine root mycorrhization; soil microorganisms; earthworms; and nutrient concentration in grapevine roots, leaves, xylem sap and grape juice. The three herbicides reduced grapevine root mycorrhization on average by 53% compared to mechanical weeding. Soil microorganisms (total colony-forming units, CFU) were significantly affected by herbicides with highest CFUs under glufosinate and lowest under glyphosate. Earthworms (surface casting activity, density, biomass, reproduction) or litter decomposition in soil were unaffected by herbicides. Herbicides altered nutrient composition in grapevine roots, leaves, grape juice and xylem sap that was collected 11 months after herbicide application. Xylem sap under herbicide treatments also contained on average 70% more bacteria than under mechanical weeding; however, due to high variability, this was not statistically significant. We conclude that interdisciplinary approaches should receive more attention when assessing ecological effects of herbicides in vineyard ecosystems.
Effects of Glyphosate-, Glufosinate- and Flazasulfuron-Based Herbicides on Soil Microorganisms in a Vineyard.
Mandl Karin,Cantelmo Clemens,Gruber Edith,Faber Florian,Friedrich Barbara,Zaller Johann G
Bulletin of environmental contamination and toxicology
In a vineyard we examined the effects of broad-spectrum herbicides with three different active ingredients (glyphosate, glufosinate, flazasulfuron) on soil microorganisms. Mechanical weeding served as control treatment. Treatments were applied within grapevine rows and soil samples taken from there in 10-20 cm depth 77 days after application. Fungi were analyzed using classical sequencing technology and bacteria using next-generation sequencing. The number of colony-forming units (CFU) comprising bacteria, yeasts and molds was higher under flazasulfuron compared to all other treatments which had similar CFU levels. Abundance of the fungus Mucor was higher under flazasulfuron than glufosinate and mechanical weeding; Mucor was absent under glyphosate. Several other fungi taxa were exclusively found under a specific treatment. Up to 160 different bacteria species were found - some of them for the first time in vineyard soils. Total bacterial counts under herbicides were on average 260% higher than under mechanical weeding; however due to high variability this was not statistically significant. We suggest that herbicide-induced alterations of soil microorganisms could have knock-on effects on other parts of the grapevine system.
Mycorrhizal Inoculation Differentially Affects Grapevine's Performance in Copper Contaminated and Non-contaminated Soils.
Nogales Amaia,Santos Erika S,Abreu Maria Manuela,Arán Diego,Victorino Gonçalo,Pereira Helena Sofia,Lopes Carlos M,Viegas Wanda
Frontiers in plant science
Plant inoculation with arbuscular mycorrhizal fungi (AMF) is increasingly employed to enhance productivity and sustainability in agricultural ecosystems. In the present study, the potential benefits of AMF inoculation on young grapevines replanted in pots containing vineyard soil with high Cu concentration were evaluated. For this purpose, one-year-old . Touriga Nacional grapevines grafted onto 1103P rootstocks were further inoculated with or , or left non-inoculated, and maintained in a sterilized substrate under greenhouse conditions for three months. After this time, half of the plants were transplanted to containers filled with an Arenosol from a vineyard which had been artificially contaminated or not with 300 mg kg of Cu. At the end of the growing season, soil nutrient concentration, soil dehydrogenase activity and mycorrhizal colonization rate were analyzed. Grapevine performance was assessed by measuring several vegetative growth and physiological parameters as well as nutrient concentrations in leaves and roots. In the non-contaminated soil, - and -inoculated plants had significantly greater root biomass than the non-inoculated ones. However, the opposite effect was observed in the Cu-contaminated soil, where non-inoculated plants performed better regarding shoot and root development. Concerning nutrient levels, an increase in Cu, Mg and Mn concentrations was observed in the roots of plants growing in the contaminated soil, although only Mn was translocated to leaves. This led to a large increase in leaf Mn concentrations, which was significantly higher in non-inoculated and - inoculated plants than in the - inoculated ones. Copper contamination induced a general decrease in leaf N, P and Fe concentrations as well as chlorosis symptoms. The largest decrease in N and P was observed in - inoculated plants, with 73 and 31.2%, respectively. However, these plants were the ones with the least decrease in Fe concentration (10% vs. almost 30% in the other two inoculation treatments). In conclusion, this study indicates that soil Cu levels can modify the outcome of AMF inoculations in young grapevines, disclosing new AMF-plant associations potentially relevant in vineyards with a tradition of Cu-based fungicide application.
Characterizing the Intra-Vineyard Variation of Soil Bacterial and Fungal Communities.
Liang Hebin,Wang Xiaowen,Yan Junwei,Luo Lixin
Frontiers in microbiology
Vineyard soil microbial communities potentially mediate grapevine growth, grape production as well as wine . Simultaneously assessing shifts of microbial community composition at the intra-vineyard scale allows us to decouple correlations among environmental variables, thus providing insights into vineyard management. Here we investigated bacterial and fungal community compositions and their relationships with edaphic properties in soils collected from a commercial vineyard at four different soil depths (0-5, 5-10, 10-20, and 20-40 cm). Soil organic carbon (SOC) content, invertase activity and phosphatase activity decreased along depth gradient in the 0-20 cm soil fraction ( < 0.001). The soil bacterial biomass and α-diversity were significantly higher than those of fungi ( ≤ 0.001). Statistical analyses revealed that SOC content, pH, C/N ratio and total phosphorus (TP) were significant determinants of soil bacterial ( = 0.494, = 0.001) and fungal ( = 0.443, = 0.001) community structure. The abundance of dominated bacterial phyla (, and ) and fungal phyla (, and ) slightly varied among all soil samples. Genus , which comprised 2.72% of the soil bacterial community, showed increasing pattern with depth. Importantly, , and were also detected with high abundances in soil samples, indicating their ecological function in soil nitrogen cycle and the potential risk in grapevine disease. Overall, this work detected the intra-vineyard variation of bacterial and fungal communities and their relationships with soil characteristics, which was beneficial to vineyard soil management and grapevine disease prevention.
Occurrence and diversity of entomopathogenic fungi (Beauveria spp. and Metarhizium spp.) in Australian vineyard soils.
Korosi Gyongyver A,Wilson Bree A L,Powell Kevin S,Ash Gavin J,Reineke Annette,Savocchia Sandra
Journal of invertebrate pathology
Entomopathogenic Ascomycetes: Hypocreales fungi occur worldwide in the soil; however, the abundance and distribution of these fungi in a vineyard environment is unknown. A survey of Australian vineyards was carried out in order to isolate and identify entomopathogenic fungi. A total of 240 soil samples were taken from eight vineyards in two states (New South Wales and Victoria). Insect baiting (using Tenebrio molitor) and soil dilution methods were used to isolate Beauveria spp. and Metarhizium spp. from all soil samples. Of the 240 soil samples, 60% contained either Beauveria spp. (26%) or Metarhizium spp. (33%). Species of Beauveria and Metarhizium were identified by sequencing the B locus nuclear intergenic region (Bloc) and elongation factor-1 alpha (EFT1) regions, respectively. Three Beauveria species (B. bassiana, B. australis and B. pseudobassiana) and six Metarhizium species (M. guizhouense, M. robertsii, M. brunneum, M. flavoviride var. pemphigi, M. pingshaense and M. majus) were identified. A new sister clade made up of six isolates was identified within B. australis. Two potentially new phylogenetic species (six isolates each) were found within the B. bassiana clade. This study revealed a diverse community of entomopathogenic fungi in sampled Australian vineyard soils.
Comparison of Aspergillus Section Nigri Species Populations in Conventional and Organic Raisin Vineyards.
Palumbo Jeffrey D,O'Keeffe Teresa L,Quejarro B Joy,Yu Alan,Zhao Alison
Species belonging to Aspergillus section Nigri are widespread in the vineyard environment, both in soil and on plant surfaces. We used plate counts and droplet digital PCR (ddPCR) methods to compare populations of the four most prevalent species (A. carbonarius, A. niger, A. welwitschiae, and A. tubingensis) over two consecutive years in conventional and organic vineyards, to determine whether management affects the potential distribution of mycotoxigenic Aspergillus species. In 2016, plate counts showed that soil populations of total filamentous fungi and of Aspergillus section Nigri species were not significantly different between conventional and organic vineyards. In 2017, while total fungal populations in soil were not significantly different, Aspergillus section Nigri populations were significantly higher in organic vineyard soil. In both years, there were no significant differences in total fungal populations and in Aspergillus section Nigri populations on fruit surfaces collected from conventional and organic vineyards. Likewise, ddPCR methods did not show significant differences in percent distribution of Aspergillus species in soil and fruit between conventional and organic vineyards. These results suggest that intervention strategies for preharvest control of potential mycotoxigenic fungi are likely to be equally compatible with either vineyard management strategy.
Characterization of the Wood Mycobiome of in a Vineyard Affected by Esca. Spatial Distribution of Fungal Communities and Their Putative Relation With Leaf Symptoms.
Del Frari Giovanni,Gobbi Alex,Aggerbeck Marie Rønne,Oliveira Helena,Hansen Lars Hestbjerg,Ferreira Ricardo Boavida
Frontiers in plant science
Esca is a disease complex belonging to the grapevine trunk diseases cluster. It comprises five syndromes, three main fungal pathogenic agents and several symptoms, both internal (i.e., affecting woody tissue) and external (e.g., affecting leaves and bunches). The etiology and epidemiology of this disease complex remain, in part, unclear. Some of the points that are still under discussion concern the sudden rise in disease incidence, the simultaneous presence of multiple wood pathogens in affected grapevines, the causal agents and the discontinuity in time of leaf symptoms manifestation. The standard approach to the study of esca has been mostly through culture-dependent studies, yet, leaving many questions unanswered. In this study, we used Illumina next-generation amplicon sequencing to investigate the mycobiome of grapevines wood in a vineyard with history of esca. We characterized the wood mycobiome composition, investigated the spatial dynamics of the fungal communities in different areas of the stem and in canes, and assessed the putative link between mycobiome and leaf symptoms. An unprecedented diversity of fungi is presented (289 taxa), including five genera reported for the first time in association with grapevines wood (, , , , and ) and numerous hitherto unreported species. Esca-associated fungi and sp. dominate the fungal community, and numerous other fungi associated with wood syndromes are also encountered (e.g., spp., ). The spatial analysis revealed differences in diversity, evenness and taxa abundances, the unique presence of certain fungi in specific areas of the plants, and tissue specificity. Lastly, the mycobiome composition of the woody tissue in proximity to leaves manifesting 'tiger stripes' symptoms of esca, as well as in leaf-symptomatic canes, was highly similar to that of plants not exhibiting any leaf symptomatology. This observation supports the current understanding that leaf symptoms are not directly linked with the fungal communities in the wood. This work builds to the understanding of the microbial ecology of the grapevines wood, offering insights and a critical view on the current knowledge of the etiology of esca.
Vineyard Soil Microbiome Composition Related to Rotundone Concentration in Australian Cool Climate 'Peppery' Shiraz Grapes.
Gupta Vadakattu V S R,Bramley Robert G V,Greenfield Paul,Yu Julian,Herderich Markus J
Frontiers in microbiology
Soil microbial communities have an integral association with plants and play an important role in shaping plant nutrition, health, crop productivity and product quality. The influence of bacteria and fungi on wine fermentation is well known. However, little is known about the role of soil microbes, other than microbial pathogens, on grape composition or their role in vintage or site () impacts on grape composition. In this study, we used an amplicon sequencing approach to investigate the potential relationships between soil microbes and inherent spatial variation in grape metabolite composition - specifically, the concentration of the 'impact aroma compound' rotundone in Shiraz grapes ( L.) grown in a 6.1 ha vineyard in the Grampians region of Victoria, Australia. Previous work had demonstrated temporal stability in patterns of within-vineyard spatial variation in rotundone concentration, enabling identification of defined 'zones' of inherently 'low' or 'high' concentration of this grape metabolite. 16S rRNA and ITS region-amplicon sequencing analysis of microbial communities in the surface soils collected from these zones indicated marked differences between zones in the genetic diversity and composition of the soil bacterial and fungal microbiome. Soils in the High rotundone zone exhibited higher diversity of bacteria, but lower diversity of fungi, compared to the soils in the Low rotundone zone. In addition, the network analysis of the microbial community in the High rotundone zone soils appeared well structured, especially with respect to the bacterial community, compared to that in the Low rotundone zone soils. The key differences in the microbial community structure between the rotundone zones are obvious for taxa/groups of both bacteria and fungi, particularly for bacteria belonging to Acidobacteria-GP4 and GP7, Rhizobiales, Gaiellaceae, Alphaproteobacteria and the Nectriaceae and Tremellaceae families of fungi. Although mulching in some parts of the vineyard caused changes in bacterial and fungal composition and overall microbial catabolic diversity and activity, its effects did not mask the rotundone zone-based variation. This finding of a systematic rotundone zone-based variation in soil microbiomes suggests an opportunity to bring together understanding of microbial ecology, plant biochemistry, and viticultural management for improved management of grape metabolism, composition and wine flavor.
A new method for extracting DNA from the grape berry surface, beginning in the vineyard.
Hall Megan E,Cadle-Davidson Lance,Fang Zhiwei,Wilcox Wayne F
Isolating DNA from microbes on the surface of a grape berry is a challenge due to their adhesion to the thick berry skin and cuticle, making studies of the grape microbiome challenging. We developed a field-to-lab DNA extraction procedure that starts in the vineyard, disrupts the grape berry surface while en route to the lab through agitation, and efficiently extracts microbial DNA from the surface of the grape. It is cost effective and utilizes commonly available laboratory chemicals with low toxicity (Table 1). This protocol allows researchers to extract DNA from the grape berry surface in the field, therefore undergoing minimal manipulation of those microbiomes before DNA extraction.
From the Vineyard to the Winery: How Microbial Ecology Drives Regional Distinctiveness of Wine.
Liu Di,Zhang Pangzhen,Chen Deli,Howell Kate
Frontiers in microbiology
Wine production is a complex process from the vineyard to the winery. On this journey, microbes play a decisive role. From the environment where the vines grow, encompassing soil, topography, weather and climate through to management practices in vineyards, the microbes present can potentially change the composition of wine. Introduction of grapes into the winery and the start of winemaking processes modify microbial communities further. Recent advances in next-generation sequencing (NGS) technology have progressed our understanding of microbial communities associated with grapes and fermentations. We now have a finer appreciation of microbial diversity across wine producing regions to begin to understand how diversity can contribute to wine quality and style characteristics. In this review, we highlight literature surrounding wine-related microorganisms and how these affect factors interact with and shape microbial communities and contribute to wine quality. By discussing the geography, climate and soil of environments and viticulture and winemaking practices, we claim microbial biogeography as a new perspective to impact wine quality and regionality. Depending on geospatial scales, habitats, and taxa, the microbial community respond to local conditions. We discuss the effect of a changing climate on local conditions and how this may alter microbial diversity and thus wine style. With increasing understanding of microbial diversity and their effects on wine fermentation, wine production can be optimised with enhancing the expression of regional characteristics by understanding and managing the microbes present.
Depth structures the community of arbuscular mycorrhizal fungi amplified from grapevine (Vitis vinifera L.) roots.
Schreiner R Paul
The diversity of arbuscular mycorrhizal fungi (AMF) associating with grapevines has been determined previously, yet little is known of how the community in roots is shaped by depth in the soil or where roots occur in different management zones of the vineyard (vine row versus alley). The influence of depth, management zone, and time of year on the community of AMF in grape roots was examined. I also tested the potential influence of the alley vegetation on AMF in grapevines by comparing the taxa amplified from roots of other plants retrieved from the alley surface soil to those from grapevines growing in the same zone. Depth shaped the AMF community in grapevine roots more than the management zone based on dissimilarity among all grapevine samples. Time of the growing season did not, although AMF taxa richness was greater in grapevine roots collected in late summer (veraison) than it was in late spring (bloom). The number of abundant AMF taxa in grapevine roots from the uppermost soil depth in the vine row was substantially lower in late spring than in late summer, and this was related to high soil nitrate in late spring. The alley vegetation comprised primarily grass, and clover plants harbored a different AMF community in roots than did intermingled grapevine roots. The change in the AMF community in a single perennial host (grape) that occurred with depth in this study resulted from a shift among common taxa as opposed to the appearance of unique taxa in the subsoil.
Forage Rotations Conserve Diversity of Arbuscular Mycorrhizal Fungi and Soil Fertility.
Pellegrino Elisa,Gamper Hannes A,Ciccolini Valentina,Ercoli Laura
Frontiers in microbiology
In the Mediterranean, long-term impact of typical land uses on soil fertility have not been quantified yet on replicated mixed crop-livestock farms and considering the variability of soil texture. Here, we report the effects, after 15 years of practice, of two legume-winter cereal rotations, olive orchards and vineyards on microbiological and chemical indicators of soil fertility and the communities of arbuscular mycorrhizal fungi (AMF). We compare the changes among these four agricultural land-use types to woodland reference sites. Root colonization by AMF of English ryegrass ( L.), a grass that occurred under all land use types, was only half as heavy in biannual berseem clover ( L.)-winter cereal rotations than in 4-year alfalfa ( L.)-winter cereal rotations. In olive ( L.) orchards and vineyards ( L.), where weeds are controlled by frequent surface tillage, the AMF root colonization of ryegrass was again much lower than in the legume-cereal rotations and at the woodland reference sites. All the microbial parameters and soil organic carbon correlated most strongly with differences in occurrence and relative abundance (β-diversity) of AMF genera in soil. The soil pH and mineral nutrients in soil strongly correlated with differences in AMF root colonization and AMF genus richness (α-diversity) in soil. Diversity of AMF was much less affected by soil texture than land use, while the opposite was true for microbial and chemical soil fertility indicators. Land uses that guaranteed a continuous ground cover of herbaceous plants and that involved only infrequent tillage, such as multiyear alfalfa-winter cereal rotation, allowed members of the AMF genus to persist and remain abundant. On the contrary, under land uses accompanied by frequent tillage and hence discontinuous presence of herbaceous plants, such as tilled olive orchard and vineyard, members of the genus dominated. These results suggest that multiyear alfalfa-winter cereal rotation with active plant growth throughout the year is the least detrimental agricultural land use in soil carbon and AMF abundance and diversity, relative to the woodland reference.
Exploring the potential of vineyards for biodiversity conservation and delivery of biodiversity-mediated ecosystem services: A global-scale systematic review.
Paiola Anna,Assandri Giacomo,Brambilla Mattia,Zottini Michela,Pedrini Paolo,Nascimbene Juri
The Science of the total environment
Vineyards are experiencing strong expansion and management intensification worldwide, especially in areas with a Mediterranean climate, which are often characterized by a high conservation value. This is posing concerns about their environmental impact and it is fostering research on biodiversity patterns and ecosystem services in this agroecosystem. With this systematic review, we aim at providing a global and comprehensive overview of the current research on biodiversity and biodiversity-mediated ecosystem services in vineyards, considering the effects of landscape features and management practices. We carried out a systematic literature search on the Web of Science Core Collection database. Literature was filtered according to several criteria, resulting in a final collection of 218 papers published between 1995 and 2018 and referring to different organism groups (from microbes to vertebrates) and two spatial scales (local and landscape). The results of the studies are often contrasting and taxon- and scale-dependent, thus hindering conclusions at the global scale. However, at least three main points of practical relevance can be fixed: (i) organic viticulture weakly enhances biodiversity at the landscape scale, whereas contrasting effects have been found at the local scale; (ii) ground vegetation management by cover cropping and the conservation of native ground cover strongly promotes biodiversity; (iii) habitat heterogeneity at the landscape and local scales is a key element for biodiversity. Several studies support the view that promoting biodiversity in vineyard-dominated landscapes could also positively impact on several ecosystem services. Our study further revealed knowledge gaps that should be filled by future research. In particular, important geographical areas for wine production, as well as several organism groups, have been completely neglected. Studies at the landscape level are still scarce (specifically those addressing landscape configuration), and also the research about supporting, provisioning, and cultural biodiversity-mediated ecosystem services is still in its infancy.
Study of the phenotypic and genotypic biodiversity of potentially ochratoxigenic black aspergilli isolated from grapes.
Dachoupakan C,Ratomahenina R,Martinez V,Guiraud J P,Baccou J C,Schorr-Galindo S
International journal of food microbiology
Ochratoxin A (OTA) is a mycotoxin with nephrotoxic, carcinogenic, teratogenic and immunotoxic effects, naturally found in agricultural products including grapes and wine. Black Aspergillus species (Section Nigri) are mainly responsible for OTA accumulation in wine grapes and in particular Aspergillus carbonarius and Aspergillus niger aggregate. The biodiversity of potentially ochratoxigenic strains of black aspergilli from different French vineyards in the southern Mediterranean region of Languedoc-Roussillon was studied. One hundred and eighty nine black strains were isolated from grapes and studied according to harvest year, production zone, grape variety and pre-harvest treatment of grapevines. The strains were identified and classified in two groups according to macroscopic and microscopic characters; these were called the A. carbonarius representative group and the A. niger aggregate representative group. Members of each group were classified in subgroups based on macroscopic morphological colony characters. Strain biodiversity was studied according to phenotypic and genotypic characterization and to the OTA production of selected strains on PDA medium. After identification was confirmed by specific PCR using primer pair ITS1/CAR and ITS1/NIG, 24 potential ochratoxigenic strains belonging to A. carbonarius and A. niger aggregate were discriminated by RAPD-PCR using 8 different OPC primers. The use of specific primers supported the identification based on phenotypic and morphological characters. RAPD-PCR patterns demonstrated a considerable diversity among the strains. Clustering among A. niger aggregate strains was associated with production zone and harvest year, but not grape variety or pre-harvest treatment. Clustering among A. carbonarius strains was not associated with any of the above parameters. OTA production of strains on culture medium seemed to correlate better with morphological characters than with genotypic profiles. No clear relation could be established between phenotypic and genotypic characters of the studied black aspergilli.
Banana-associated microbial communities in Uganda are highly diverse but dominated by Enterobacteriaceae.
Rossmann Bettina,Müller Henry,Smalla Kornelia,Mpiira Samuel,Tumuhairwe John Baptist,Staver Charles,Berg Gabriele
Applied and environmental microbiology
Bananas are among the most widely consumed foods in the world. In Uganda, the country with the second largest banana production in the world, bananas are the most important staple food. The objective of this study was to analyze banana-associated microorganisms and to select efficient antagonists against fungal pathogens which are responsible for substantial yield losses. We studied the structure and function of microbial communities (endosphere, rhizosphere, and soil) obtained from three different traditional farms in Uganda by cultivation-independent (PCR-SSCP fingerprints of 16S rRNA/ITS genes, pyrosequencing of enterobacterial 16S rRNA gene fragments, quantitative PCR, fluorescence in situ hybridization coupled with confocal laser scanning microscopy, and PCR-based detection of broad-host-range plasmids and sulfonamide resistance genes) and cultivation-dependent methods. The results showed microhabitat-specific microbial communities that were significant across sites and treatments. Furthermore, all microhabitats contained a high number and broad spectrum of indigenous antagonists toward identified fungal pathogens. While bacterial antagonists were found to be enriched in banana plants, fungal antagonists were less abundant and mainly found in soil. The banana stem endosphere was the habitat with the highest bacterial counts (up to 10(9) gene copy numbers g(-1)). Here, enterics were found to be enhanced in abundance and diversity; they provided one-third of the bacteria and were identified by pyrosequencing with 14 genera, including not only potential human (Escherichia, Klebsiella, Salmonella, and Yersinia spp.) and plant (Pectobacterium spp.) pathogens but also disease-suppressive bacteria (Serratia spp.). The dominant role of enterics can be explained by the permanent nature and vegetative propagation of banana and the amendments of human, as well as animal, manure in these traditional cultivations.
Resilience of the natural phyllosphere microbiota of the grapevine to chemical and biological pesticides.
Perazzolli Michele,Antonielli Livio,Storari Michelangelo,Puopolo Gerardo,Pancher Michael,Giovannini Oscar,Pindo Massimo,Pertot Ilaria
Applied and environmental microbiology
The phyllosphere is colonized by complex microbial communities, which are adapted to the harsh habitat. Although the role and ecology of nonpathogenic microorganisms of the phyllosphere are only partially understood, leaf microbiota could have a beneficial role in plant growth and health. Pesticides and biocontrol agents are frequently applied to grapevines, but the impact on nontarget microorganisms of the phyllosphere has been marginally considered. In this study, we investigated the effect of a chemical fungicide (penconazole) and a biological control agent (Lysobacter capsici AZ78) on the leaf microbiota of the grapevine at three locations. Amplicons of the 16S rRNA gene and of the internal transcribed spacer were sequenced for bacterial and fungal identification, respectively. Pyrosequencing analysis revealed that the richness and diversity of bacterial and fungal populations were only minimally affected by the chemical and biological treatments tested, and they mainly differed according to grapevine locations. Indigenous microbial communities of the phyllosphere are adapted to environmental and biotic factors in the areas where the grapevines are grown, and they are resilient to the treatments tested. The biocontrol properties of phyllosphere communities against downy mildew differed among grapevine locations and were not affected by treatments, suggesting that biocontrol communities could be improved with agronomic practices to enrich beneficial populations in vineyards.
Mating of natural Saccharomyces cerevisiae strains for improved glucose fermentation and lignocellulosic inhibitor tolerance.
Jansen Trudy,Hoff Justin Wallace,Jolly Neil,van Zyl Willem Heber
Natural Saccharomyces cerevisiae isolates from vineyards in the Western Cape, South Africa were evaluated for ethanol production in industrial conditions associated with the production of second-generation biofuels. The strains displayed high phenotypic diversity including the ability to grow at 45 °C and in the presence of 20% (v/v) ethanol, strain YI13. Strains HR4 and YI30 were inhibitor-tolerant under aerobic and oxygen-limited conditions, respectively. Spore-to-spore hybridization generated progeny that displayed heterosis, including increased ethanol productivity and improved growth in the presence of a synthetic inhibitor cocktail. Hybrid strains HR4/YI30#6 and V3/YI30#6 were able to grow at a high salt concentration (2 mol/L NaCl) with V3/YI30#6 also able to grow at a high temperature (45 °C). Strains HR4/YI30#1 and #3 were inhibitor-tolerant, with strain HR4/YI30#3 having similar productivity (0.36 ± 0.0036 g/L per h) as the superior parental strain, YI30 (0.35 ± 0.0058 g/L per h). This study indicates that natural S. cerevisiae strains display phenotypic variation and heterosis can be achieved through spore-to-spore hybridization. Several of the phenotypes (temperature-, osmo-, and inhibitor tolerance) displayed by both the natural strains and the generated progeny were at the maximum conditions reported for S. cerevisiae strains.
Grape berry yeast communities: influence of fungicide treatments.
Milanović Vesna,Comitini Francesca,Ciani Maurizio
International journal of food microbiology
The yeast communities colonising grape berry surfaces were evaluated for the influence of fungicide treatments in an organic vineyard (copper/sulphur-based products) and a conventional vineyard (commonly used fungicides). Analysis of yeast abundance and diversity was carried out on grape berries and juice during fermentation, using culture-dependent and -independent approaches. Yeast abundance was as generally reported for mature grapes and it was slight higher from grapes treated with conventional fungicides. Initial grape samples showed less yeast species diversity in the organic vineyard compared with the conventional one. In both vineyards, the dominant yeast were Candida zemplinina and Hanseniaspora uvarum (>50%), respectively, typical species that colonise surfaces of mature grape berries. Metschnikowia pulcherrima was widely found in the conventional samples while it was only occasionally found in organic ones. Saccharomyces cerevisiae was isolated only at the end of natural fermentation (conducted in sterile condition), with lower levels in the organic samples. S. cerevisiae strains showed less intraspecies diversity in the organic samples (two genotypes), in comparison with the conventional samples (six genotypes).
A Method to Detect and Quantify Eutypa lata and Diplodia seriata-Complex DNA in Grapevine Pruning Wounds.
Pouzoulet Jérôme,Rolshausen Philippe E,Schiavon Marco,Bol Sebastiaan,Travadon Renaud,Lawrence Daniel P,Baumgartner Kendra,Ashworth Vanessa E,Comont Gwénaëlle,Corio-Costet Marie-France,Pierron Romain J G,Besson Xavier,Jacques Alban
Trunk diseases are factors that limit sustainability of vineyards worldwide. Botryosphaeria and Eutypa diebacks are caused by several fungi belonging to the Botryosphaeriaceae and Diatrypaceae, respectively, with Diplodia seriata and Eutypa lata being two of the most common species. Previous information indicated that the traditional isolation method used to detect these pathogens from plant samples could underestimate their incidence levels. In the present study, we designed two sets of primers that target the β-tubulin gene and that are amenable for quantitative real-time PCR (qPCR) Sybr-Green assays for the detection and quantification of D. seriata-complex (DseCQF/R) and E. lata (ElQF/R) DNA. The design of a species-specific assay was achieved for E. lata. For D. seriata, a species-specific assay could not be designed. The low interspecific diversity across β-tubulin genes resulted in an assay that could not discriminate D. seriata from some closely related species either not yet reported or presenting a low prevalence on grapevine, such as D. intermedia. We validated our technique on grapevine spur samples naturally and artificially infected with D. seriata and E. lata during the dormant season. Experimental grapevines were located in two counties of northern California where the incidence of both pathogens was previously reported. The qPCR assays revealed that a high frequency of pruning wound infections (65%) was achieved naturally by E. lata, while low infection frequency (less than 5%) was observed using the reisolation method. For D. seriata-complex, low (5%) to no natural infection frequencies were observed by the qPCR and the reisolation method, respectively. These results also provided evidence that our qPCR detection methods were more sensitive to assess the incidence of E. lata and D. seriata-complex in plant samples, than traditional isolation techniques. Benefits of molecular methods for the detection of canker pathogens in the field under natural conditions are discussed.
Influence of the farming system and vine variety on yeast communities associated with grape berries.
Cordero-Bueso Gustavo,Arroyo Teresa,Serrano Ana,Tello Javier,Aporta Irene,Vélez María Dolores,Valero Eva
International journal of food microbiology
Wine production in most countries is based on the use of commercial strains leading to the colonisation of the wineries by these strains with the consequent reduction of autochthonous biodiversity. This implies that wine styles could therefore become standardised. The vineyard could be an important source of native yeasts of oenological interest. For this reason the objective of this study was to compare two agronomic conditions with the aim of preserving yeast biodiversity in the vineyard. A three year sampling plan was designed to evaluate the influence of different agronomic parameters on the biodiversity of fermentative grape yeasts. Thus two vineyards, one organic and one conventional, with three different grape varieties (Shiraz, Grenache and Barbera) were chosen. In total, 27 samples were collected from both vineyards. Of these, 1080 colonies were isolated and a total of 9 species were identified. The strains identified as Saccharomyces cerevisiae were genotyped by microsatellite analysis obtaining nine different electrophoretic patterns. Classical ecology indexes were used to obtain the richness (S), the biodiversity (H') and the dominance (D) of the species studied. The results indicated a clear influence on grape associated yeast diversity of the phytosanitary treatment used in the vineyard. This is the first time that classical ecology indexes have been used to study the ecology of the spontaneous fermentation of grape musts and the species Candida sorbosa and Pichia toletana have been described in vineyards of the Madrid winegrowing region.
Genotype-Environment Interaction Shapes the Microbial Assemblage in Grapevine's Phyllosphere and Carposphere: An NGS Approach.
Singh Prashant,Santoni Sylvain,This Patrice,Péros Jean-Pierre
Plant surface or phyllosphere is the habitat of hyperdiverse microbial communities and it is always exposed to the fluctuating environmental factors, which is thought to be one of the potential drivers of microbial community structuring. Impact of grapevine genotypes in variable environmental factors (i.e., at different geographic locations) on the phyllosphere has never been studied and is the main objective of this report. Using high throughput short amplicon sequencing of 16S rRNA genes and internal transcribed spacer (ITS), we analyzed the impacts of genotypes of (coming from three genetic pool), on the microbial (bacterial and fungal) assemblage in the phyllosphere. First, we performed the analysis of the phyllosphere microbiome while using fifteen genotypes that were chosen to maximize intra-specific diversity and grown in two Mediterranean vineyards. Then, the same analysis was performed on five commercially important varieties of that were sampled from three different French agro-climatic zones (or terroir: a combination of climate, soils, and human practices). Our study revealed that, at a particular geographic location, genotypes have an impact on microbial assemblage in the phyllosphere and carposphere of leaf and fruit (or berries), respectively, which is more prominent on the carposphere but the effect of terroir was much stronger than the genotype when the leaf phyllosphere of five grapevine varieties grown in different agro-climatic zones was compared. Impacts of the season and exterior plant organs (leaf and berries) on microbial taxa structuring in the phyllosphere was also assessed and presented in this report.
From grape berries to wine: population dynamics of cultivable yeasts associated to "Nero di Troia" autochthonous grape cultivar.
Garofalo Carmela,Tristezza Mariana,Grieco Francesco,Spano Giuseppe,Capozzi Vittorio
World journal of microbiology & biotechnology
The aim of this work was to study the biodiversity of yeasts isolated from the autochthonous grape variety called "Uva di Troia", monitoring the natural diversity from the grape berries to wine during a vintage. Grapes were collected in vineyards from two different geographical areas and spontaneous alcoholic fermentations (AFs) were performed. Different restriction profiles of ITS-5.8S rDNA region, corresponding to Saccharomyces cerevisiae, Issatchenkia orientalis, Metschnikowia pulcherrima, Hanseniaspora uvarum, Candida zemplinina, Issatchenkia terricola, Kluyveromyces thermotolerans, Torulaspora delbrueckii, Metschnikowia chrysoperlae, Pichia fermentans, Hanseniaspora opuntiae and Hanseniaspora guilliermondii, were observed. The yeast occurrences varied significantly from both grape berries and grape juices, depending on the sampling location. Furthermore, samples collected at the end of AF revealed the great predominance of Saccharomyces cerevisiae, with a high intraspecific biodiversity. This is the first report on the population dynamics of 'cultivable' microbiota diversity of "Uva di Troia" cultivar from the grape to the corresponding wine ("Nero di Troia"), and more general for Southern Italian oenological productions, allowing us to provide the basis for an improved management of wine yeasts (with both non-Saccharomyces and Saccharomyces) for the production of typical wines with desired unique traits. A certain geographical-dependent variability has been reported, suggesting the need of local based formulation for autochthonous starter cultures, especially in the proportion of the different species/strains in the design of mixed microbial preparations.
Microbiome of vineyard soils is shaped by geography and management.
Coller Emanuela,Cestaro Alessandro,Zanzotti Roberto,Bertoldi Daniela,Pindo Massimo,Larger Simone,Albanese Davide,Mescalchin Enzo,Donati Claudio
BACKGROUND:Despite their importance as a reservoir of biodiversity, the factors shaping soil microbial communities and the extent by which these are impacted by cultivation are still poorly understood. Using 16S rRNA gene and ITS sequencing, we characterized the soil microbiota of vineyards and of neighboring permanent grassland soils in the Italian province of Trentino, and correlated their structure and composition to location, chemical properties of the soil, and land management. RESULTS:Bacterial communities had a core of conserved taxa accounting for more than 60% of the reads of each sample, that was influenced both by geography and cultivation. The core fungal microbiota was much smaller and dominated by geography alone. Cultivation altered the structure and composition of the soil microbiota both for bacteria and fungi, with site-specific effects on their diversity. The diversity of bacterial and fungal communities was generally inversely correlated across locations. We identified several taxa that were impacted by the chemical properties and texture of the soil. CONCLUSIONS:Our results highlight the different responses of bacterial and fungal communities to environmental factors and highlight the need to characterize both components of the soil microbiota to fully understand the factors that drive their variability.
PCR ITS-RFLP: A useful method for identifying filamentous fungi isolates on grapes.
Diguta C F,Vincent B,Guilloux-Benatier M,Alexandre H,Rousseaux S
Restriction digestion analysis of the ITS products was tested as an easy method to identify isolates of filamentous fungi on grapes. Endonucleases SduI, HinfI, MseI, HaeIII were used. Endonucleases BfmI, Cfr9I, Hpy188I, MaeII or PspGI were used as necessary to complete discrimination. The 43 species studied generated 42 different composite profiles. Only the species P. thomii and P. glabrum gave the same composite profile. 96.3% strains tested could be differentiated to the species level with only four enzymes. Hundred ninety nine strains of filamentous fungi were isolated from various vineyards in Burgundy and identified by this method. Penicillium (58.5%) was the genus the most frequently isolated and no strains of the genus Aspergillus was isolated. P. spinolusum was the most isolated species of Penicillium (22.70%). The species C. cladiosporioides, B. cinerea, E. nigrum, A. alternata, T. koningiopsis, P. diplodiella, C. herbarum, A. alternatum, T. cucumeris and F. oxysporum were also isolated. This technique is a rapid and reliable method appropriate for routine identification of filamentous fungi. This can be used to screen large numbers of isolates from various environments in a short time. This is the first exhaustive study of fungal diversity at species level in vineyard.
[Effects of grape-replanting on soil bacterial and fungal populations].
Li Kun,Guo Xiu-wu,Sun Ying-ni,Zhang Li-heng,Hu Xi-xi
Ying yong sheng tai xue bao = The journal of applied ecology
Rhizosphere and non-rhizosphere soil samples were collected from the vineyards having been planted for 3 and 30 years, and PCR-DGGE technique was adopted to study the effects of grape-replanting on the population structure and diversity of soil bacteria and fungi. The bacterial and fungal diversities were higher in 30-year-planted vineyard than in 3-year-planted vineyard, and higher in rhizosphere soil than in non-rhizosphere soil. After 30 years replanting, the population structure of bacteria and fungi approached the same in rhizosphere soil and non-rhizosphere soil but differed from that in fallow soil; while in the 3-year-planted vineyard, the population structure in rhizosphere soil was different from that in non-rhizosphere soil and fallow soil. Comparing with that in 3-year-planted vineyard, the rhizosphere soil microbial population in 30-year-planted vineyard had a greater change. In bacterial population, Flavobacterium sp. (DQ339585) and Bacillus sp. (AY039821) decreased while Pedobacter sp. (AJ871084) increased; in fungal population, Omphalina farinolens (EF413029) appeared, Pestalotiopsis sp. (DQ657877, DQ657875, DQ657871), Phacidium lacerum (DQ470976), and Lecythophora decumbens (AF353597) decreased, while Pilidium acerinum voucher (AY48709) increased. Bacillus sp., Flavobacterium sp. , and Pestalotiopsis sp. had antagonism to pathogen, and their decrease reduced the resistance of grape against pathogen. The increase of Pilidium acerinum voucher might relate to the severe disease after grape-replanting.
Diversity of diatrypaceous fungi associated with grapevine canker diseases in California.
Trouillas Florent P,Urbez-Torres José R,Gubler Walter D
Eutypa lata is the most common diatrypaceous fungus in grapevine cankers. This study was undertaken to determine the presence and diversity of other members of the Diatrypaceae in grapevines in California. We isolated into pure culture 11 species of Diatrypaceae from the wood of diseased grapevines including Cryptosphaeria pullmanensis, Cryptovalsa ampelina, Diatrype oregonensis, D. stigma, D. whitmanensis, Diatrype sp., Diatrypella verrucaeformis and four putative species of Eutypella. Species were identified or grouped morphologically and by phylogenetic analyses of the complete sequence of the internal transcribed spacer (ITS) of the rDNA and beta-tubulin gene. Diatrypaceous fungi also occurred frequently on the native flora surrounding vineyards, thus serving as possible inoculum sources for these putative pathogens.
Ecological restoration of a copper polluted vineyard: Long-term impact of farmland abandonment on soil bio-chemical properties and microbial communities.
Cavani Luciano,Manici Luisa M,Caputo Francesco,Peruzzi Elisabetta,Ciavatta Claudio
Journal of environmental management
This study aimed at investigating the degree of interference of high soil copper (Cu) contamination when an old vineyard is converted into a protected area. This study was performed within an intensive agricultural system; it was organized into a two-factorial nested design to analyze the impact of management (conventional vs re-naturalized orchard) and position within each orchard (tree-rows and strips). Chemical and biochemical properties along with bacterial and fungal communities, evaluated with PCR-DGGE starting from total soil DNA, were analyzed. Total Cu was localized in tree rows in the old vineyard at 1000 mg kg(-1) of soil, whereas it did not exceed 80 mg kg(-1) soil in the other treatments. Total organic carbon and all biochemical properties significantly improved in re-naturalized compared to conventionally cultivated site, while no significant differences were observed between tree row and strip. Moreover, a higher extractable carbon-extractable nitrogen (Cext-to-Next) ratio in the re-naturalized (19.3) site than in the conventionally managed site (10.2) indicated a shift of soil system from C-limited to N-limited, confirming a successful ecological restoration. Deep improvement of soil biochemical properties exceeded the negative impact of Cu contamination. A shift of bacterial community composition as well as increased bacterial diversity in Cu contaminated treatment indicated a bacterial response to Cu stress; to the contrary, soil fungi were less susceptible than bacteria, though an overall reduction of fungal DNA was detected. Findings suggest that ecological restoration of highly polluted agricultural soils leads to overcoming the reduction of soil functionalities linked to Cu contamination and opens interesting perspectives for mitigating Cu stress in agricultural soils with strategies based on conservative agriculture.
Taxonomic and Functional Characterization of the Microbial Community During Spontaneous Fermentation of Riesling Must.
Sirén Kimmo,Mak Sarah Siu Tze,Melkonian Chrats,Carøe Christian,Swiegers Jan Hendrik,Molenaar Douwe,Fischer Ulrich,Gilbert M Thomas P
Frontiers in microbiology
Although there is an extensive tradition of research into the microbes that underlie the winemaking process, much remains to be learnt. We combined the high-throughput sequencing (HTS) tools of metabarcoding and metagenomics, to characterize how microbial communities of Riesling musts sampled at four different vineyards, and their subsequent spontaneously fermented derivatives, vary. We specifically explored community variation relating to three points: (i) how microbial communities vary by vineyard; (ii) how community biodiversity changes during alcoholic fermentation; and (iii) how microbial community varies between musts that successfully complete alcoholic fermentation and those that become 'stuck' in the process. Our metabarcoding data showed a general influence of microbial composition at the vineyard level. Two of the vineyards (4 and 5) had strikingly a change in the differential abundance of . We therefore additionally performed shotgun metagenomic sequencing on a subset of the samples to provide preliminary insights into the potential relevance of this observation, and used the data to both investigate functional potential and reconstruct draft genomes (bins). At these two vineyards, we also observed an increase in non-Saccharomycetaceae fungal functions, and a decrease in bacterial functions during the early fermentation stage. The binning results yielded 11 coherent bins, with both vineyards sharing the yeast bins and . Read recruitment and functional analysis of this data revealed that during fermentation, a high abundance of might serve as a biocontrol agent against bacteria, via a putative iron depletion pathway, and this in turn could help dominate the fermentation. During alcoholic fermentation, we observed a general decrease in biodiversity in both the metabarcoding and metagenomic data. Unexpected behavior was observed in vineyard 4 according to metagenomic analyses based on reference-based read mapping. Analysis of open reading frames using these data showed an increase of functions assigned to class Actinobacteria in the end of fermentation. Therefore, we hypothesize that bacteria might sit-and-wait until activity slows down. Complementary approaches to annotation instead of relying a single database provide more coherent information true species. Lastly, our metabarcoding data enabled us to identify a relationship between stuck fermentations and abundance. Given that robust chemical analysis indicated that although the stuck samples contained residual glucose, all fructose had been consumed, we hypothesize that this was because fructophilic , rather than , dominated these fermentations. Overall, our results showcase the different ways in which metagenomic analyses can improve our understanding of the wine alcoholic fermentation process.
diversity and pathogenicity revealed from a broad survey of grapevine diseases in Europe.
Guarnaccia V,Groenewald J Z,Woodhall J,Armengol J,Cinelli T,Eichmeier A,Ezra D,Fontaine F,Gramaje D,Gutierrez-Aguirregabiria A,Kaliterna J,Kiss L,Larignon P,Luque J,Mugnai L,Naor V,Raposo R,Sándor E,Váczy K Z,Crous P W
Species of are considered important plant pathogens, saprobes, and endophytes on a wide range of plant hosts. Several species are well-known on grapevines, either as agents of pre- or post-harvest infections, including Phomopsis cane and leaf spot, cane bleaching, swelling arm and trunk cankers. In this study we explore the occurrence, diversity and pathogenicity of spp. associated with in major grape production areas of Europe and Israel, focusing on nurseries and vineyards. Surveys were conducted in Croatia, Czech Republic, France, Hungary, Israel, Italy, Spain and the UK. A total of 175 strains were isolated from asymptomatic and symptomatic shoots, branches and trunks. A multi-locus phylogeny was established based on five genomic loci (ITS, , , and ), and the morphological characters of the isolates were determined. Preliminary pathogenicity tests were performed on green grapevine shoots with representative isolates. The most commonly isolated species were and . Four new species described here as , , and were found associated with affected vines. Pathogenicity tests revealed , , and as pathogens of grapevines. No symptoms were caused by . This study represents the first report of and on grapevines in Europe. The present study improves our understanding of the species associated with several disease symptoms on plants, and provides useful information for effective disease management.
Diversity of thermophilic and thermotolerant fungi in corn grain.
Sandona Katrina,Billingsley Tobias Terri L,Hutchinson Miriam I,Natvig Donald O,Porras-Alfaro Andrea
Corn bins in the midwestern United States can reach temperatures up to 52 C. High temperatures combined with sufficient moisture and humidity in bins provide the perfect environment to promote the growth of thermophilic and thermotolerant fungi. In this article, we characterize for the first time thermophilic and thermotolerant fungi in corn grain bins using culture-based methods and pyrosequencing techniques. Corn samples were collected from local farms in western Illinois. Samples were plated and incubated at 50 C using a variety of approaches. Of several hundred kernels examined, more than 90% showed colonization. Species identified using culture methods included , and . Pyrosequencing was also performed directly on corn grain using fungal-specific primers to determine whether thermophilic fungi could be detected using this technique. Sequences were dominated by pathogenic fungi, and thermophiles were represented by less than 2% of the sequences despite being isolated from 90% of the grain samples using culturing techniques. The high abundance of previously undocumented viable fungi in corn could have negative implications for grain quality and pose a potential risk for workers and consumers of corn-derived products in the food industry. Members of the Sordariales were absent among thermophile isolates and were not represented in nuc rDNA internal transcribed spacer (ITS) sequences. This is in striking contrast with results obtained with other substrates such as litter, dung, and soils, where mesophilic and thermophilic members of the Sordariaceae and Chaetomiaceae are common. This absence appears to reflect an important difference between the ecology of Sordariales and other orders within the Ascomycota in terms of their ability to compete in microhabitats rich in sugars and living tissues.
Diversity and phylogeny of resveratrol-producing culturable endophytic fungi from species in India.
Dwibedi Vagish,Saxena Sanjai
In the present study, resveratrol producing culturable endophytes were recovered from the Indian vineyards. Of the 145 endophytic fungi recovered, only 30.3% were positive for resveratrol production in the preliminary screening. Culture broth of only 13 isolates exhibited the actual presence of resveratrol in the range of 4.4-52.3 μg/ml by HPLC quantification. The most potent endophytic isolate producing the highest extracellular resveratrol was #19VVLPM isolated from the Pinot Noir variety. Further LC-MS analysis confirmed the similarity of fungal resveratrol with standard resveratrol. The Merlot variety exhibited the highest colonization frequency of the resveratrol-producing fungal endophytes. Using morphological methods as well as molecular phylogeny #19VVLPM was identified as . It is a promising candidate for further development into a commercial strain.
The yeast Starmerella bacillaris (synonym Candida zemplinina) shows high genetic diversity in winemaking environments.
Masneuf-Pomarede Isabelle,Juquin Elodie,Miot-Sertier Cécile,Renault Philippe,Laizet Yec'han,Salin Franck,Alexandre Hervé,Capozzi Vittorio,Cocolin Luca,Colonna-Ceccaldi Benoit,Englezos Vasileios,Girard Patrick,Gonzalez Beatriz,Lucas Patrick,Mas Albert,Nisiotou Aspasia,Sipiczki Matthias,Spano Giuseppe,Tassou Chrysoula,Bely Marina,Albertin Warren
FEMS yeast research
The yeast Candida zemplinina (Starmerella bacillaris) is frequently isolated from grape and wine environments. Its enological use in mixed fermentation with Saccharomyces cerevisiae has been extensively investigated these last few years, and several interesting features including low ethanol production, fructophily, glycerol and other metabolites production, have been described. In addition, molecular tools allowing the characterization of yeast populations have been developed, both at the inter- and intraspecific levels. However, most of these fingerprinting methods are not compatible with population genetics or ecological studies. In this work, we developed 10 microsatellite markers for the C. zemplinina species that were used for the genotyping of 163 strains from nature or various enological regions (28 vineyards/wineries from seven countries). We show that the genetic diversity of C. zemplinina is shaped by geographical localization. Populations isolated from winemaking environments are quite diverse at the genetic level: neither clonal-like behaviour nor specific genetic signature were associated with the different vineyards/wineries. Altogether, these results suggest that C. zemplinina is not under selective pressure in winemaking environments.
The vineyard yeast microbiome, a mixed model microbial map.
Setati Mathabatha Evodia,Jacobson Daniel,Andong Ursula-Claire,Bauer Florian Franz,Bauer Florian
Vineyards harbour a wide variety of microorganisms that play a pivotal role in pre- and post-harvest grape quality and will contribute significantly to the final aromatic properties of wine. The aim of the current study was to investigate the spatial distribution of microbial communities within and between individual vineyard management units. For the first time in such a study, we applied the Theory of Sampling (TOS) to sample gapes from adjacent and well established commercial vineyards within the same terroir unit and from several sampling points within each individual vineyard. Cultivation-based and molecular data sets were generated to capture the spatial heterogeneity in microbial populations within and between vineyards and analysed with novel mixed-model networks, which combine sample correlations and microbial community distribution probabilities. The data demonstrate that farming systems have a significant impact on fungal diversity but more importantly that there is significant species heterogeneity between samples in the same vineyard. Cultivation-based methods confirmed that while the same oxidative yeast species dominated in all vineyards, the least treated vineyard displayed significantly higher species richness, including many yeasts with biocontrol potential. The cultivatable yeast population was not fully representative of the more complex populations seen with molecular methods, and only the molecular data allowed discrimination amongst farming practices with multivariate and network analysis methods. Importantly, yeast species distribution is subject to significant intra-vineyard spatial fluctuations and the frequently reported heterogeneity of tank samples of grapes harvested from single vineyards at the same stage of ripeness might therefore, at least in part, be due to the differing microbiota in different sections of the vineyard.
High Genetic Diversity and Species Complexity of Associated With Grapevine Dieback in China.
Manawasinghe Ishara S,Dissanayake Asha J,Li Xinghong,Liu Mei,Wanasinghe Dhanushka N,Xu Jianping,Zhao Wensheng,Zhang Wei,Zhou Yueyan,Hyde Kevin D,Brooks Siraprapa,Yan Jiye
Frontiers in microbiology
Grapevine trunk diseases have become one of the main threats to grape production worldwide, with species as an emerging group of pathogens in China. At present, relatively little is known about the taxonomy and genetic diversity of Chinese populations, including their relationships to other populations worldwide. Here, we conducted an extensive field survey in six provinces in China to identify and characterize species in grape vineyards. Ninety-four isolates were identified and analyzed using multi-locus phylogeny. The isolates belonged to eight species, including three novel taxa, , and three new host records, , and . The most commonly isolated species was . In addition, high genetic diversity was observed for in Chinese vineyards. Haplotype network analysis of isolates from China and Europe showed a close relationship between samples from the two geographical locations and evidence for recombination. In comparative pathogenicity testing, was the most aggressive taxon, whereas was the least aggressive. This study provides new insights into the species associated with grapevines in China, and our results can be used to develop effective disease management strategies.
Geographical Origin Has a Greater Impact on Grape Berry Fungal Community than Grape Variety and Maturation State.
Kioroglou Dimitrios,Kraeva-Deloire Elena,Schmidtke Leigh M,Mas Albert,Portillo Maria C
We used barcoded sequencing to analyze the eukaryotic population in the grape berries at different ripening states in four Australian vineyards. Furthermore, we used an innovative compositional data analysis for assessing the diversity of microbiome communities. The novelty was the introduction of log-ratio balances between the detected genera. Altogether, our results suggest that fungal communities were more impacted by the geographical origin of the Australian vineyards than grape variety and harvest time. Even if the most abundant genera were and , they were ubiquitous to all samples and were not discriminative. In fact, the balances and the fungal community structure seemed to be greatly affected by changes of the genera , , , , and . These results were not evident from the comparison of relative abundance based on OTU counts alone, remarking the importance of the balance analysis for microbiome studies.
Genetic diversity and population structure of Saccharomyces cerevisiae strains isolated from different grape varieties and winemaking regions.
Schuller Dorit,Cardoso Filipa,Sousa Susana,Gomes Paula,Gomes Ana C,Santos Manuel A S,Casal Margarida
We herein evaluate intraspecific genetic diversity of fermentative vineyard-associated S. cerevisiae strains and evaluate relationships between grape varieties and geographical location on populational structures. From the musts obtained from 288 grape samples, collected from two wine regions (16 vineyards, nine grape varieties), 94 spontaneous fermentations were concluded and 2820 yeast isolates were obtained that belonged mainly (92%) to the species S. cerevisiae. Isolates were classified in 321 strains by the use of ten microsatellite markers. A high strain diversity (8-43 strains per fermentation) was associated with high percentage (60-100%) of fermenting samples per vineyard, whereas a lower percentage of spontaneous fermentations (0-40%) corresponded to a rather low strain diversity (1-10 strains per fermentation).For the majority of the populations, observed heterozygosity (Ho) was about two to five times lower than the expected heterozygosity (He). The inferred ancestry showed a very high degree of admixture and divergence was observed between both grape variety and geographical region. Analysis of molecular variance showed that 81-93% of the total genetic variation existed within populations, while significant differentiation within the groups could be detected. Results from AMOVA analysis and clustering of allelic frequencies agree in the distinction of genetically more dispersed populations from the larger wine region compared to the less extended region. Our data show that grape variety is a driver of populational structures, because vineyards with distinct varieties harbor genetically more differentiated S. cerevisiae populations. Conversely, S. cerevisiae strains from vineyards in close proximity (5-10 km) that contain the same grape variety tend to be less divergent. Populational similarities did not correlate with the distance between vineyards of the two wine regions. Globally, our results show that populations of S. cerevisiae in vineyards may occur locally due to multi-factorial influences, one of them being the grape variety.
Small scale fungal community differentiation in a vineyard system.
Knight Sarah J,Karon Ophir,Goddard Matthew R
Microbes influence the quality of agricultural commodities and contribute to their distinctive sensorial attributes. Increasingly studies have demonstrated not only differential geographic patterns in microbial communities and populations, but that these contribute to valuable regionally distinct agricultural product identities, the most well-known example being wine. However, little is understood about microbial geographic patterns at scales of less than 100 km. For wine, single vineyards are the smallest (and most valuable) scale at which wine is asserted to differ; however, it is unknown whether microbes play any role in agricultural produce differentiation at this scale. Here we investigate whether vineyard fungal communities and yeast populations driving the spontaneous fermentation of fruit from these same vineyards are differentiated using metagenomics and population genetics. Significant differentiation of fungal communities was revealed between four Central Otago (New Zealand) Pinot Noir vineyard sites. However, there was no vineyard demarcation between fermenting populations of S. cerevisiae. Overall, this provides evidence that vineyard microbiomes potentially contribute to vineyard specific attributes in wine. Understanding the scale at which microbial communities are differentiated, and how these communities influence food product attributes has direct economic implications for industry and could inform sustainable management practices that maintain and enhance microbial diversity.
Wine microbiology is driven by vineyard and winery anthropogenic factors.
Grangeteau Cédric,Roullier-Gall Chloé,Rousseaux Sandrine,Gougeon Régis D,Schmitt-Kopplin Philippe,Alexandre Hervé,Guilloux-Benatier Michèle
The effects of different anthropic activities (vineyard: phytosanitary protection; winery: pressing and sulfiting) on the fungal populations of grape berries were studied. The global diversity of fungal populations (moulds and yeasts) was performed by pyrosequencing. The anthropic activities studied modified fungal diversity. Thus, a decrease in biodiversity was measured for three successive vintages for the grapes of the plot cultivated with Organic protection compared to plots treated with Conventional and Ecophyto protections. The fungal populations were then considerably modified by the pressing-clarification step. The addition of sulfur dioxide also modified population dynamics and favoured the domination of the species Saccharomyces cerevisiae during fermentation. The non-targeted chemical analysis of musts and wines by FT-ICR-MS showed that the wines could be discriminated at the end of alcoholic fermentation as a function of adding SO or not, but also and above all as a function of phytosanitary protection, regardless of whether these fermentations took place in the presence of SO or not. Thus, the existence of signatures in wines of chemical diversity and microbiology linked to vineyard protection has been highlighted.
Effects of different management regimes on microbial biodiversity in vineyard soils.
Hendgen Maximilian,Hoppe Björn,Döring Johanna,Friedel Matthias,Kauer Randolf,Frisch Matthias,Dahl Andreas,Kellner Harald
An active and diverse soil biota is important for maintaining crop productivity and quality, and preservation of these traits is a major goal of sustainable farming. This study aimed at unravelling the impact of different management practices on soil fungal and bacterial biodiversity in vineyards as a model for permanent crops. Species diversity was assessed using an amplicon sequencing approach in a long-term field experiment in the Rheingau wine region of Germany where integrated, organic and biodynamic management practices had been in place for 10 years. Fungal community composition under integrated management differed significantly from organic and biodynamic management, whereas fungal species richness remained unaffected. Soil under integrated management had a significantly reduced bacterial species richness compared to organic, but community composition was similar to organically and biodynamically managed soils. Highest fungal richness was obtained under cover crop between rows in topsoil, arising from cover cropping and organic carbon supply.
Factors Affecting the Vineyard Populational Diversity of .
Boso Susana,Gago Pilar,Santiago José-Luis,de la Fuente María,Martínez María-Carmen
The plant pathology journal
is very susceptible to downy mildew () A number of authors have suggested different genetic populations of this fungus exist in Europe, each showing a different degree of virulence. Work performed to date indicates this diversity to be the result of different factors. In areas where gene flow is greater and recombination more frequent, the diversity of appears to be wider. In vineyards isolated by geographic barriers, a race may become dominant and produce clonal epidemics driven by asexual reproduction. The aim of the present work was to identify the conditions that influence the genetic diversity of populations in the vineyards of northwestern Spain, where the climatic conditions for the growth of this fungus are very good. Vineyards situated in a closed, narrow valley of the interior, in more open valleys, and on the coast were sampled and the populations of detected were differentiated at the molecular level through the examination of microsatellite markers. The populations of represented in primary and secondary infections were investigated in the same way. The concentration of airborne sporangia in the vegetative cycle was also examined, as was the virulence of the different populations detected. The epidemiological characteristics of the fungus differed depending on the degree of isolation of the vineyard, the airborne spore concentration, and on whether the attack was primary or secondary. Strong isolation was associated with the appearance of dominant fungal races and, therefore, reduced populational diversity.
Bacterial and fungal communities and contribution of physicochemical factors during cattle farm waste composting.
Huhe ,Jiang Chao,Wu Yanpei,Cheng Yunxiang
During composting, the composition of microbial communities is subject to constant change owing to interactions with fluctuating physicochemical parameters. This study explored the changes in bacterial and fungal communities during cattle farm waste composting and aimed to identify and prioritize the contributing physicochemical factors. Microbial community compositions were determined by high-throughput sequencing. While the predominant phyla in the bacterial and fungal communities were largely consistent during the composting, differences in relative abundances were observed. Bacterial and fungal community diversity and relative abundance varied significantly, and inversely, over time. Relationships between physicochemical factors and microbial community compositions were evaluated by redundancy analysis. The variation in bacterial community composition was significantly related to water-soluble organic carbon (WSOC), and pile temperature and moisture (p < .05), while the largest portions of variation in fungal community composition were explained by pile temperature, WSOC, and C/N (p < .05). These findings indicated that those parameters are the most likely ones to influence, or be influenced by the bacterial and fungal communities. Variation partitioning analyses indicated that WSOC and pile temperature had predominant effects on bacterial and fungal community composition, respectively. Our findings will be useful for improving the quality of cattle farm waste composts.
Soil microbiota respond to green manure in organic vineyards.
Longa C M O,Nicola L,Antonielli L,Mescalchin E,Zanzotti R,Turco E,Pertot I
Journal of applied microbiology
AIMS:The aim of this work was to investigate the effects of biodynamic management with and without the addition of green manure, in comparison with organic management, on the microbiota in vineyards soil. METHODS AND RESULTS:High throughput sequencing was used to compare the taxonomic structure of the soil bacterial and fungal communities from vineyards managed with different methods (organic, biodynamic or biodynamic with green manure). Our results showed that microbial communities associated with biodynamic and organic farming systems were very similar, while green manure was the greatest source of soil microbial biodiversity and significantly changed microbial richness and community composition compared with other soils. Green manure also significantly enriched bacterial taxa involved in the soil nitrogen cycle (e.g. Microvirga sp., Pontibacter sp. and Nitrospira sp.). CONCLUSIONS:Our results showed that the diversity and composition of the microbial communities associated with biodynamic and organic farming systems were similar, indicating that the use of biodynamic preparations 500 and 501 did not cause any significant detectable changes to the soil microbial community in the short term, while the effects of green manure were significant in soil microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY:The microbiological richness and structure of soil are used as a sensitive indicator of soil quality. The extension of organic/biodynamic farming, associated with green manure application, could contribute to increase the abundance of functional groups of biological and agronomical relevance and maintaining microbial biodiversity in vineyard soils.
Characterization of fungal communities of developmental stages in table grape grown in the northern region of South Africa.
Carmichael P C,Siyoum N,Chidamba L,Korsten L
Journal of applied microbiology
AIMS:To determine fungal communities that characterize table grapes during berry development. METHODS AND RESULTS:Two agro-ecologically different table grape commercial farms (site A and B) were used in this study. Samples were collected at full bloom, pea size and mature stages, from three positions (inside centre, eastern and western peripheral ends) per site. Total DNA extraction, Illumina sequencing and analysis of 18 pooled samples for fungal diversity targeting ITS1-2 generated a total of 2 035 933 high-quality sequences. The phylum Ascomycota (77.0%) and Basidiomycota (23.0%) were the most dominant, while the genera, Alternaria (33.1%) and Cladosporium (24.2%) were the overall dominant postharvest decay causing fungi throughout the developmental stages. Inside centre of site A were more diverse at full bloom (3.82) than those at the peripheral ends (<3.8), while at site B, the peripheral ends showed better diversity, particularly the eastern part at both full bloom (3.3) and pea size (3.7). CONCLUSION:Fungal population diversity varies with different phenological table grape growth stages and is further influenced by site and vine position within a specific vineyard. SIGNIFICANCE AND IMPACT OF THE STUDY:The information on fungal diversity and succession in table grapes during preharvest growth stages is critical in the development of a more targeted control strategy, to improve postharvest quality of table grapes.
The diversity of arbuscular mycorrhizal fungi amplified from grapevine roots (Vitis vinifera L.) in Oregon vineyards is seasonally stable and influenced by soil and vine age.
Schreiner R Paul,Mihara Keiko L
The diversity of arbuscular mycorrhizal fungi (AMF) in 10 Oregon vineyards was assessed by examining spores in soil and amplifying mycorrhizal DNA from roots. Seventeen spore morphotypes were found in soil, including seven species in the Acaulosporaceae. Eighteen phylotypes were amplified from grape roots with AM1 and NS31 primers, and clones were dominated by Glomus spp. (> 99%). A few clones (< 1%) representing a single phylotype within Gigasporaceae, and a single clone within Archaeosporaceae were amplified from roots with AM1-NS31 primers. A separate experiment employing known proportions of grape roots colonized by Glomus intraradices or by Gigaspora rosea showed that fungi within Gigasporaceae might be underrepresented in clone abundance when Glomus spp. co-occur in roots. No clones representing fungi within the Acaulosporaceae were amplified from vineyards, although specific fungi within Acaulosporaceae were shown to colonize Pinot noir roots in sterilized soil and were amplified from these roots. Four Glomus phylotypes, including G. intraradices, were found in roots from all 10 vineyards, and these fungi accounted for 81% of clones. AMF phylotypes amplified from roots did not change during the growing season, although six phylotypes varied with soil type. The presence of three phylotypes was affected by vineyard age, and phylotype richness appeared to decline as vineyard age increased beyond 20 y. PCA analysis supported the hypothesis that the AMF community is different in red-hill soils than in valley soils and indicated certain phylotypes might be associated with lower soil and vine nutrient status. However, the changes in the AMF community in grape roots across vineyards were subtle because most root samples were dominated by the same three or four phylotypes. A separate analysis using primers to amplify AMF from the Archeasporaceae/Paraglomeraceae showed most root samples also were colonized by at least one Paraglomus or Archaeospora phylotype.
Genetic and pathogenic diversity of Neofusicoccum parvum in New Zealand vineyards.
Baskarathevan Jeyaseelan,Jaspers Marlene V,Jones E Eirian,Cruickshank Robert H,Ridgway Hayley J
Genetic diversity of 50 isolates of Neofusicoccum parvum, the predominant species of the Botryosphaeriaceae recovered from grapevines displaying symptoms of dieback and decline in New Zealand, was compared to that of isolates from Australia, South Africa, and California. The eight universally primed polymerase chain reaction (UP-PCR) primers distinguished 56 genotypes, with only four clonal pairs found. Seven main groups were identified in a neighbour-joining (NJ) tree with isolates from different regions and vineyards of New Zealand, Australia, and California distributed in different groups, indicating a high level of intra and intervineyard genetic variation. All of the South African isolates were positioned in a separate UP-PCR group, indicating that these isolates were less related to the other N. parvum isolates. When compared to fungi that reproduce sexually the genetic diversity and Shannon diversity indices were low (0.076-0.249; 0.109-0.367, respectively), genetic identity levels were high (0.76-0.95), and genetic distance levels were low (0.04-0.27). The large number of genotypes and the low number of clones in the New Zealand N. parvum populations may be explained by parasexual recombination as anastomosis was observed between nonself pairings. Pathogenicity tests using isolates from different UP-PCR groups inoculated onto either green shoots or 1-y-old grapevines detected virulence diversity, indicating intra and intervineyard variation between isolates, however, no correlation was detected between UP-PCR group and virulence.
Biodiversity of Saccharomyces cerevisiae populations in Malbec vineyards from the "Zona Alta del Río Mendoza" region in Argentina.
Mercado Laura,Sturm María Elena,Rojo María Cecilia,Ciklic Iván,Martínez Claudio,Combina Mariana
International journal of food microbiology
The "Zona Alta del Río Mendoza" (ZARM) is the major Malbec grape viticulture region of Argentina. The aim of the present study was to explore Saccharomyces cerevisiae biodiversity in ZARM vineyards. Interdelta PCR and RFLP mtDNA molecular markers were applied to differentiate S. cerevisiae strains. The presence of commercial strains on ZARM vineyards was also assessed. Our results reveal a highly diverse, but genetically closely related, S. cerevisiae population (containing more than 190 molecular patterns among 590 S. cerevisiae isolates). According to the S. cerevisiae strain diversity found in vineyards, they were classified as vineyards with high and low polymorphic S. cerevisiae populations. Six vineyards showed a high polymorphic population, with more than 20 different S. cerevisiae molecular patterns. S. cerevisiae populations in these vineyards were diverse and irregularly distributed, with different strains in each vineyard site. Low polymorphic S. cerevisiae population vineyards displayed very low yeast diversity, with only 9 to 10 different S. cerevisiae strains and presence of two commercial strains widely distributed. Population diversity estimators were calculated to determine the population structure of S. cerevisiae in the ZARM vineyards. The obtained values support the hypothesis that the eight sampled subpopulations come indeed from a larger population.
Distribution and diversity of arbuscular mycorrhizal fungi in grapevines from production vineyards along the eastern Adriatic coast.
Likar Matevž,Hančević Katarina,Radić Tomislav,Regvar Marjana
The colonisation and diversity of arbuscular mycorrhizal fungi (AMF) on roots of grapevines were investigated in production vineyards located along a 500-km-long stretch of karst along the coast of the Adriatic Sea. AMF communities on roots of grapevines were analysed using temporal temperature gel electrophoresis and sequencing of the 18S and internal transcribed spacer segments of the rDNA operon. The AMF colonisation of these grapevines roots was consistent along the whole of this east Adriatic karst region, at 64 to 82% of fine roots. The comparison of the AMF communities on the roots of these grapevines showed that the fungal community associated with grapevine roots seems to be relatively stable, with inter-vineyard variability comparable to intra-vineyard variability. Some of the changes in the fungal communities were attributed to environmental factors (plant-available P) and location of the vineyard, although the latter could also have been influenced by an unmeasured environmental factor. A total of 27 taxa of fungi were identified, including taxa from Glomus group B, based on the sequencing of 18S rDNA. Sequencing of the internal transcribed spacer rDNA yielded 30 different fungal taxa, which comprised eight different Glomeromycota taxa, including Glomus sinuosum and Glomus indicum. To our knowledge, this is the first report of grapevine colonisation by G. indicum.
Comparison of soil microbial communities inhabiting vineyards and native sclerophyllous forests in central Chile.
Castañeda Luis E,Godoy Karina,Manzano Marlene,Marquet Pablo A,Barbosa Olga
Ecology and evolution
Natural ecosystems provide services to agriculture such as pest control, soil nutrients, and key microbial components. These services and others in turn provide essential elements that fuel biomass productivity. Responsible agricultural management and conservation of natural habitats can enhance these ecosystem services. Vineyards are currently driving land-use changes in many Mediterranean ecosystems. These land-use changes could have important effects on the supporting ecosystems services related to the soil properties and the microbial communities associated with forests and vineyard soils. Here, we explore soil bacterial and fungal communities present in sclerophyllous forests and organic vineyards from three different wine growing areas in central Chile. We employed terminal restriction fragment length polymorphisms (T-RFLP) to describe the soil microbial communities inhabiting native forests and vineyards in central Chile. We found that the bacterial community changed between the sampled growing areas; however, the fungal community did not differ. At the local scale, our findings show that fungal communities differed between habitats because fungi species might be more sensitive to land-use change compared to bacterial species, as bacterial communities did not change between forests and vineyards. We discuss these findings based on the sensitivity of microbial communities to soil properties and land-use change. Finally, we focus our conclusions on the importance of naturally derived ecosystem services to vineyards.
Analysis of fungal diversity of grapes by application of temporal temperature gradient gel electrophoresis - potentialities and limits of the method.
Doaré-Lebrun E,El Arbi A,Charlet M,Guérin L,Pernelle J-J,Ogier J-C,Bouix M
Journal of applied microbiology
AIMS:Fungi could be responsible for several problems in wines but the fungal ecosystem of grapes remains little known. The use of traditional methods does not allow to describe quickly this ecosystem. Therefore, we need to improve the knowledge about these fungi to prevent defects in wine. This study aims at evaluating the potentialities of the temporal temperature gradient gel electrophoresis (TTGE) method to describe the fungal ecosystem of grapes. METHODS AND RESULTS:The internal transcribed spacer (ITS) region was amplified and analysed using TTGE. A reference database of 56 fungal species was set up to evaluate the discrimination power of the method. The database was used for the direct identification of the fungal species present in complex samples. The sensitivity of the method is below 10(4) spores per ml. CONCLUSIONS:This method allows to describe the fungal diversity of grapes, but does not always allow to directly identify all fungal species, because of the taxonomic resolution of the ITS sequences. However, this identification strategy is less time consuming than traditional analysis by cloning and sequencing the bands. SIGNIFICANCE AND IMPACT OF THE STUDY:With this method, it will be possible to compare the fungal species present in different vineyards and to connect the presence of some fungi with particular defects in wine.
From vineyard to winery: a source map of microbial diversity driving wine fermentation.
Morrison-Whittle Peter,Goddard Matthew R
Humans have been making wine for thousands of years and microorganisms play an integral part in this process as they not only drive fermentation, but also significantly influence the flavour, aroma and quality of finished wines. Since fruits are ephemeral, they cannot comprise a permanent microbial habitat; thus, an age-old unanswered question concerns the origin of fruit and ferment associated microbes. Here we use next-generation sequencing approaches to examine and quantify the roles of native forest, vineyard soil, bark and fruit habitats as sources of fungal diversity in ferments. We show that microbial communities in harvested juice and ferments vary significantly across regions, and that while vineyard fungi account for ∼40% of the source of this diversity, uncultivated ecosystems outside of vineyards also prove a significant source. We also show that while communities in harvested juice resemble those found on grapes, these increasingly resemble fungi present on vine bark as the ferment proceeds.
Responses of Soil Bacterial and Fungal Communities to Organic and Conventional Farming Systems in East China.
Zhang Hanlin,Zheng Xianqing,Bai Naling,Li Shuangxi,Zhang Juanqin,Lv Weiguang
Journal of microbiology and biotechnology
Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of , , , , , , , , and , and has the potential to strengthen soil metabolic ability with . On the other hand, CF increased the intensity of nitrogen cycling with , , , and , but enriched several pathogen fungal members, including , , , , , and .
Sequence-based Analysis of the Vitis vinifera L. cv Cabernet Sauvignon Grape Must Mycobiome in Three South African Vineyards Employing Distinct Agronomic Systems.
Setati Mathabatha E,Jacobson Daniel,Bauer Florian F
Frontiers in microbiology
Recent microbiomic research of agricultural habitats has highlighted tremendous microbial biodiversity associated with such ecosystems. Data generated in vineyards have furthermore highlighted significant regional differences in vineyard biodiversity, hinting at the possibility that such differences might be responsible for regional differences in wine style and character, a hypothesis referred to as "microbial terroir." The current study further contributes to this body of work by comparing the mycobiome associated with South African (SA) Cabernet Sauvignon grapes in three neighboring vineyards that employ different agronomic approaches, and comparing the outcome with similar data sets from Californian vineyards. The aim of this study was to fully characterize the mycobiomes associated with the grapes from these vineyards. The data revealed approximately 10 times more fungal diversity than what is typically retrieved from culture-based studies. The Biodynamic vineyard was found to harbor a more diverse fungal community (H = 2.6) than the conventional (H = 2.1) and integrated (H = 1.8) vineyards. The data show that ascomycota are the most abundant phylum in the three vineyards, with Aureobasidium pullulans and its close relative Kabatiella microsticta being the most dominant fungi. This is the first report to reveal a high incidence of K. microsticta in the grape/wine ecosystem. Different common wine yeast species, such as Metschnikowia pulcherrima and Starmerella bacillaris dominated the mycobiome in the three vineyards. The data show that the filamentous fungi are the most abundant community in grape must although they are not regarded as relevant during wine fermentation. Comparison of metagenomic datasets from the three SA vineyards and previously published data from Californian vineyards revealed only 25% of the fungi in the SA dataset was also present in the Californian dataset, with greater variation evident amongst ubiquitous epiphytic fungi.
Fungal endophytes of wild and hybrid Vitis leaves and their potential for vineyard biocontrol.
Kernaghan Gavin,Mayerhofer Michael,Griffin Amanda
Canadian journal of microbiology
Plants are colonized by diverse assemblages of fungal endophytes that have potential as biocontrol agents for a variety of crops, including grapevine. Although the diversity of symbionts can be very high in wild plants, the fungal endophytes of wild Vitis plants have not yet been investigated. We surveyed the fungal endophytes of 6 wild populations of Vitis riparia, as well as a cold-tolerant, hybrid grapevine in 5 vineyards (1 certified organic), using 454 pyrosequencing. We detected between 43 and 235 operational taxonomic units per sample, with the highest richness and diversity in the wild, the lowest in conventional vineyards, and intermediate levels in the organic vineyard. Wild plants supported a range of taxa not seen in the conventional vineyards, and vineyards were dominated by relatively few taxa. We also isolated fungi from the wild plants and tested them for their ability to inhibit pathogens of grapevine. Several wild isolates (e.g., Ramularia spp.) were strongly inhibitory to grapevine pathogens. We show that wild Vitis supports a distinct and highly diverse community of fungal endophytes and may represent a rich repository of potential vineyard biocontrol agents.
Fungal diversity in grape must and wine fermentation assessed by massive sequencing, quantitative PCR and DGGE.
Wang Chunxiao,García-Fernández David,Mas Albert,Esteve-Zarzoso Braulio
Frontiers in microbiology
The diversity of fungi in grape must and during wine fermentation was investigated in this study by culture-dependent and culture-independent techniques. Carignan and Grenache grapes were harvested from three vineyards in the Priorat region (Spain) in 2012, and nine samples were selected from the grape must after crushing and during wine fermentation. From culture-dependent techniques, 362 isolates were randomly selected and identified by 5.8S-ITS-RFLP and 26S-D1/D2 sequencing. Meanwhile, genomic DNA was extracted directly from the nine samples and analyzed by qPCR, DGGE and massive sequencing. The results indicated that grape must after crushing harbored a high species richness of fungi with Aspergillus tubingensis, Aureobasidium pullulans, or Starmerella bacillaris as the dominant species. As fermentation proceeded, the species richness decreased, and yeasts such as Hanseniaspora uvarum, Starmerella bacillaris and Saccharomyces cerevisiae successively occupied the must samples. The "terroir" characteristics of the fungus population are more related to the location of the vineyard than to grape variety. Sulfur dioxide treatment caused a low effect on yeast diversity by similarity analysis. Because of the existence of large population of fungi on grape berries, massive sequencing was more appropriate to understand the fungal community in grape must after crushing than the other techniques used in this study. Suitable target sequences and databases were necessary for accurate evaluation of the community and the identification of species by the 454 pyrosequencing of amplicons.
ITS fungal barcoding primers versus 18S AMF-specific primers reveal similar AMF-based diversity patterns in roots and soils of three mountain vineyards.
Berruti Andrea,Desirò Alessandro,Visentin Stefano,Zecca Odoardo,Bonfante Paola
Environmental microbiology reports
ITS primers commonly used to describe soil fungi are flawed for AMF although it is unknown the extent to which they distort the interpretation of community patterns. Here, we focus on how the use of a specific ITS2 fungal barcoding primer pair biased for AMF changes the interpretation of AMF community patterns from three mountain vineyards compared to a novel AMF-specific approach on the 18S. We found that although discrepancies were present in the taxonomic composition of the two resulting datasets, the estimation of diversity patterns among AMF communities was similar and resulted in both primer systems being able to correctly assess the community-structuring effect of location, compartment (root vs. soil) and environment. Both methodologies made it possible to detect the same alpha-diversity trend among the locations under study but not between root and soil transects. We show that the ITS2 primer system for fungal barcoding provides a good estimate of both AMF community structure and relation to environmental variables. However, this primer system does not fit in with cross-compartment surveys (roots vs. soil) as it can underestimate AMF diversity in soil samples. When specifically focusing on AMF, the 18S primer system resulted in wide coverage and marginal non-target amplification.
Fungal diversity, incidence and mycotoxin contamination in grapes from two agro-climatic Spanish regions with emphasis on Aspergillus species.
García-Cela Esther,Crespo-Sempere Ana,Gil-Serna Jessica,Porqueres Aleix,Marin Sonia
Journal of the science of food and agriculture
BACKGROUND:Fourteen vineyards from two different agro-climatic regions in Spain were sampled in two consecutive years in order to determinate the grape mycobiota and diversity indexes with the final aim to define the potential mycotoxigenic species from both regions and their relationship. RESULTS:The most common fungal genera encountered were Aspergillus (30.0%), Alternaria (53.2%), Cladosporium (11.9%) and Penicillium (2.9%). Black aspergilli presence in the hotter region (south) was significantly higher (P < 0.05) than in the northeast in both years. Among black aspergilli, A. tubingensis seemed to be the better adapted species to environmental conditions, while A. carbonarius was the main potentially ochratoxigenic species in both regions and years, owing to the most relevant percentage of ochratoxigenic isolates. Ochratoxin A (OTA)-positive musts were only detected from southern vineyards, although contamination was always lower than 0.1 µg L(-1) . Finally, none of black aspergilli tested produced fumonisins (FBs) on Czapek yeast extract agar (CYA), while 63% of A. niger tested produced FB2 when inoculated on CYA20S, reaching 100% of isolates from the south. CONCLUSION:Climate change scenarios in southern Europe point to an increase in temperature and drought. This could promote particularly adapted species such as A. niger, decreasing OTA risk, but this could lead to an increase in FB2 presence.
Revealing Cues for Fungal Interplay in the Plant-Air Interface in Vineyards.
Abdelfattah Ahmed,Sanzani Simona M,Wisniewski Michael,Berg Gabriele,Cacciola Santa O,Schena Leonardo
Frontiers in plant science
Plant-associated microorganisms play a crucial role in plant health and productivity. Belowground microbial diversity is widely reported as a major factor in determining the composition of the plant microbiome. In contrast, much less is known about the role of the atmosphere in relation to the plant microbiome. The current study examined the hypothesis that the atmospheric microbiome influences the composition of fungal communities of the aboveground organs (flowers, fruit, and leaves) of table grape and . The atmosphere surrounding grape plantings exhibited a significantly higher level of fungal diversity relative to the nearby plant organs and shared a higher number of phylotypes (5,536 OTUs, 40.3%) with the plant than between organs of the same plant. Using a Bayesian source tracking approach, plant organs were determined to be the major source of the atmospheric fungal community (92%). In contrast, airborne microbiota had only a minor contribution to the grape microbiome, representing the source of 15, 4, and 35% of the fungal communities of leaves, flowers, and fruits, respectively. Moreover, data indicate that plant organs and the surrounding atmosphere shared a fraction of each other's fungal communities, and this shared pool of fungal taxa serves as a two-way reservoir of microorganisms. Microbial association analysis highlighted more positive than negative interactions between fungal phylotypes. Positive interactions were more common within the same environment, while negative interactions appeared to occur more frequently between different environments, i.e., atmosphere, leaf, flower, and fruit. The current study revealed the interplay between the fungal communities of the grape phyllosphere with the surrounding air. Plants were identified as a major source of recruitment for the atmospheric microbiome, while the surrounding atmosphere contributed only a small fraction of the plant fungal community. The results of the study suggested that the plant-air interface modulates the plant recruitment of atmospheric fungi, taking a step forward in understanding the plant holobiont assembly and how the atmosphere surrounding plants plays a role in this process. The impact of plants on the atmospheric microbiota has several biological and epidemiological implications for plants and humans.
The Fungal and Bacterial Rhizosphere Microbiome Associated With Grapevine Rootstock Genotypes in Mature and Young Vineyards.
Berlanas Carmen,Berbegal Mónica,Elena Georgina,Laidani Meriem,Cibriain José Félix,Sagües Ana,Gramaje David
Frontiers in microbiology
The microbiota colonizing the rhizosphere and the endorhizosphere contribute to plant growth, productivity, carbon sequestration, and phytoremediation. Several studies suggested that different plants types and even genotypes of the same plant species harbor partially different microbiomes. Here, we characterize the rhizosphere bacterial and fungal microbiota across five grapevine rootstock genotypes cultivated in the same soil at two vineyards and sampling dates over 2 years by 16S rRNA gene and ITS high-throughput amplicon sequencing. In addition, we use quantitative PCR (qPCR) approach to measure the relative abundance and dynamic changes of fungal pathogens associated with black-foot disease. The objectives were to (1) unravel the effects of rootstock genotype on microbial communities in the rhizosphere of grapevine and (2) to compare the relative abundances of sequence reads and DNA amount of black-foot disease pathogens. Host genetic control of the microbiome was evident in the rhizosphere of the mature vineyard. Microbiome composition also shifted as year of sampling, and fungal diversity varied with sampling moments. Linear discriminant analysis identified specific bacterial (i.e., ) and fungal (i.e., ) taxa associated with grapevine rootstocks. Host genotype did not predict any summary metrics of rhizosphere α- and β-diversity in the young vineyard. Regarding black-foot associated pathogens, a significant correlation between sequencing reads and qPCR was observed. In conclusion, grapevine rootstock genotypes in the mature vineyard were associated with different rhizosphere microbiomes. The latter could also have been affected by age of the vineyard, soil properties or field management practices. A more comprehensive study is needed to decipher the cause of the rootstock microbiome selection and the mechanisms by which grapevines are able to shape their associated microbial community. Understanding the vast diversity of bacteria and fungi in the rhizosphere and the interactions between microbiota and grapevine will facilitate the development of future strategies for grapevine protection.
Fungal diversity of root vegetables and soil rhizosphere collected from organic and conventional farms in Eastern Poland.
Kłapeć Teresa,Cholewa Grażyna,Cholewa Alicja,Dutkiewicz Jacek,Wójcik-Fatla Angelina
Annals of agricultural and environmental medicine : AAEM
OBJECTIVE:Determination of the concentration and species composition of filamentous fungi in root vegetables (carrots and red beetroots), and the adjacent rhizosphere soil, collected on organic and conventional farms in Eastern Poland. MATERIAL AND METHODS:During the period 2015-2016, a total number of 80 samples of vegetables and 40 samples of soil were examined. From each type of farm, 20 samples of vegetables and 20 samples of the adjacent soil were examined. In addition, the study included 20 samples of vegetables from organic farms and 20 samples of vegetables from conventional farms purchased on the markets in the city of Lublin in Eastern Poland. In order to determine the concentration and species composition of filamentous fungi, both in vegetables and soil, the method of plate dilutions on Malt Agar medium (Difco) with chloramphenicol was used. The study was conducted in two parallel repetitions. Inoculated media were incubated at the temperature of 30° C for 72 hours, then at room temperature for 72 hours. The species composition of fungal flora was determined using macroscopic and microscopic methods, with the help of keys and atlases. RESULTS:It was found that the mean concentration of fungi was higher in vegetables and soil from conventional farms than in those from organic farms. In the case of carrots and soil from conventional farms, this concentration was 4.93 and 5.10 log<sub>10</sub> CFU g<sup>-1</sup>, respectively, whereas from organic farms - respectively, 3.81 and 4.20 log<sub>10</sub> CFU g<sup>-1</sup>. In the case of beetroots and soil from conventional farms, the mean concentrations were also higher compared to organic farms - 5.09 vs. 3.93 and 4.95 vs. 4.23 log<sub>10</sub> CFU g<sup>-1</sup>. In the examined vegetables and rhizosphere soil, 61 species of filamentous fungi were found, of which 12 belonged to the genus <i>Penicillium</i>, 4 to the genus Fusarium, and 2 species each to the genera: <i>Aspergillus, Cladosporium</i> and <i>Trichoderma</i>. As many as 28 (45.9%) fungal species that occurred in vegetables and soil are regarded as pathogenic for humans.
Fungal Diversity in Tomato Rhizosphere Soil under Conventional and Desert Farming Systems.
Kazerooni Elham A,Maharachchikumbura Sajeewa S N,Rethinasamy Velazhahan,Al-Mahrouqi Hamed,Al-Sadi Abdullah M
Frontiers in microbiology
This study examined fungal diversity and composition in conventional (CM) and desert farming (DE) systems in Oman. Fungal diversity in the rhizosphere of tomato was assessed using 454-pyrosequencing and culture-based techniques. Both techniques produced variable results in terms of fungal diversity, with 25% of the fungal classes shared between the two techniques. In addition, pyrosequencing recovered more taxa compared to direct plating. These findings could be attributed to the ability of pyrosequencing to recover taxa that cannot grow or are slow growing on culture media. Both techniques showed that fungal diversity in the conventional farm was comparable to that in the desert farm. However, the composition of fungal classes and taxa in the two farming systems were different. Pyrosequencing revealed that and are the two most common fungal classes in CM and DE, respectively. However, the culture-based technique revealed that Eurotiomycetes was the most abundant class in both farming systems and some classes, such as , were not detected by the culture-based technique. Although some plant pathogens (e.g., or ) were detected in the rhizosphere of tomato, the majority of fungal species in the rhizosphere of tomato were saprophytes. Our study shows that the cultivation system may have an impact on fungal diversity. The factors which affected fungal diversity in both farms are discussed.
454-Pyrosequencing Reveals Variable Fungal Diversity Across Farming Systems.
Kazeeroni Elham A,Al-Sadi Abdullah M
Frontiers in plant science
Oasis farming system is common in some parts of the world, especially in the Arabian Peninsula and several African countries. In Oman, the farming system in the majority of farms follows a semi-oasis farming (SOF) system, which is characterized by growing multiple crops mainly for home consumption, but also for local market. This study was conducted to investigate fungal diversity using pyrosequencing approach in soils from a farm utilizing a SOF system which is cultivated with date palms, acid limes and cucumbers. Fungal diversity from this farm was compared to that from an organic farm (OR) growing cucumbers and tomatoes. Fungal diversity was found to be variable among different crops in the same farm. The observed OTUs, Chao1 richness estimates and Shannon diversity values indicated that soils from date palms and acid limes have higher fungal diversity compared to soil from cucumbers (SOF). In addition, they also indicated that the level of fungal diversity is higher in the rhizosphere of cucumbers grown in OR compared to SOF. Ascomycota was the most dominant phylum in most of the samples from the OR and SOF farms. Other dominant phyla are Microsporidia, Chytridiomycota, and Basidiomycota. The differential level of fungal diversity within the SOF could be related to the variation in the cultural practices employed for each crop.
Metagenomic analysis exploring taxonomic and functional diversity of soil microbial communities in Chilean vineyards and surrounding native forests.
Castañeda Luis E,Barbosa Olga
Mediterranean biomes are biodiversity hotspots, and vineyards are important components of the Mediterranean landscape. Over the last few decades, the amount of land occupied by vineyards has augmented rapidly, thereby increasing threats to Mediterranean ecosystems. Land use change and agricultural management have important effects on soil biodiversity, because they change the physical and chemical properties of soil. These changes may also have consequences on wine production considering that soil is a key component of . Here, we describe the taxonomic diversity and metabolic functions of bacterial and fungal communities present in forest and vineyard soils in Chile. To accomplish this goal, we collected soil samples from organic vineyards in central Chile and employed a shotgun metagenomic approach to sequence the microbial DNA. Additionally, we studied the surrounding native forest to obtain a baseline of the soil conditions in the area prior to the establishment of the vineyard. Our metagenomic analyses revealed that both habitats shared most of the soil microbial species. The most abundant genera in the two habitats were the bacteria and and the fungus . Our results suggest that the soil microbial communities are similar in these forests and vineyards. Therefore, we hypothesize that native forests surrounding the vineyards may be acting as a microbial reservoir buffering the effects of the land conversion. Regarding the metabolic diversity, we found that genes pertaining to the metabolism of amino acids, fatty acids, and nucleotides as well as genes involved in secondary metabolism were enriched in forest soils. On the other hand, genes related to miscellaneous functions were more abundant in vineyard soils. These results suggest that the metabolic function of microbes found in these habitats differs, though differences are not related to taxonomy. Finally, we propose that the implementation of environmentally friendly practices by the wine industry may help to maintain the microbial diversity and ecosystem functions associated with natural habitats.
Environmental yeast communities in vineyards in the mountains of Santa Catarina State, Brazil.
Mendes S D C,Ramírez-Castrillón M,Feldberg N P,Bertoldi F C,Valente P
World journal of microbiology & biotechnology
Yeasts were isolated from three vineyards located in the South Region of Brazil. A cross evaluation was carried out at the oldest vineyard of the study in Pinheiro Preto. Samples of grape berries, grapevine leaves and the soil, along with samples of the winery equipment and effluent, were collected. In the Serra do Marari and Campos Novos vineyards only samples of grape clusters were obtained. The 106 yeast isolates were identified by sequencing the D1/D2 domain of LSU rDNA or ITS1-5.8S-ITS2 region in 22 species. The values for the richness indices varied between the vineyards. A comparison of the taxonomic diversity of the yeasts from these regions using the reciprocal Simpson index showed a significant difference between the Serra do Marari and Campos Novos vineyards (5.72 ± 0.36 and 2.92 ± 0.36, respectively, p < 0.0001). The functional diversity was assessed in relation to the use of carbon and nitrogen sources by the yeasts isolated from each location. In general, we observed that the Pinheiro Preto and Campos Novos vineyards differed consistently from the Serra do Marari vineyard according to these indices (FAD2, FDc and Rao, p < 0.0001). The possible spreading of Saccharomyces cerevisiae from the winery to the vineyard in Pinheiro Preto was observed.