Structural features of biologically active extracellular polysaccharide produced by green microalgae Dictyosphaerium chlorelloides.
International journal of biological macromolecules
Ion-exchange chromatography of the biologically active extracellular biopolymer produced by D. chlorelloides yielded ten fractions differing in yield, protein content, monosaccharide composition and molecular weight distribution. Their sugar compositional analyses showed rhamnogalactans, substituted to different extent by mannose and glucose, as a dominant EPS component in all fractions (91 %) except one containing arabinogalactan (7 %). In highly branched rhamnogalactans the quantity of linear (1,3-; 1,4- and 1,6-linked) and branched β-D-galactose units (1,3,6-, 1,4,6- and 1,3,4,6-linked) was nearly equal. From various α-L-rhamnose linkages the 1,2,4-linkage was dominant. Data indicate a rhamnogalactan backbone of EPS, branched by terminal mannose and glucose units, and a lot of O-methylated derivatives of galactose residues (2-O-methyl, 2,3-O-dimethyl, 3-O-methyl and 6-O-methyl). In individual fractions their content and type varied. Detail study of the arabinogalactan showed that its backbone consists of 1,3-linked β-D-Galp units; some of them are branched through O-4 by 6-OMe-α-D-Galp- (1 → 2) -α-L-Araf side chain, other through O-6 by 3-OMe-β-D-Galp, 6-OMe-β-D-Galp, β-D-Galp and β-D-Galf.
10.1016/j.ijbiomac.2022.05.197
Structural characteristics and immune-enhancing activity of an extracellular polysaccharide produced by marine Halomonas sp. 2E1.
Wang QingChi,Wei Maosheng,Zhang Jingjing,Yue Yang,Wu Ning,Geng Lihua,Sun Chaomin,Zhang Quanbin,Wang Jing
International journal of biological macromolecules
Microbial polysaccharides from extreme environments, such as cold seeps and hydrothermal vents, usually exhibit novel structural features and diverse biological activities. In this study, an exopolysaccharide (EPS2E1) was isolated from cold-seep bacterium Halomonas sp. 2E1 and its immune-enhancing activity was evaluated. The total sugar content and protein content were determined as 83.1% and 7.9%, respectively. EPS2E1 contained mannose and glucose with the molar ratio of 3.76: 1. The molecular weight was determined to be 47.0 kDa. Structural analysis indicated that EPS2E1 was highly branched, the backbone mainly consisted of →2)-Man-(α-1→ and →2, 6)-Man-(α-1→ with the ratio of 2.45: 1.00. The chain also contained →4)-Glc-(α-1→, →6)-Man-(α-1→ and →3)-Glc-(β-1→. EPS2E1 could significantly increase the production of NO, COX-2, TNF-α, IL-1β and IL-6 by activating the MAPK and NF-κB pathways on RAW264.7 macrophages. EPS2E1 exhibits the potential to be an immunopotentiator in the near future.
10.1016/j.ijbiomac.2021.05.143
Extracellular polysaccharide with novel structure and antioxidant property produced by the deep-sea fungus Aspergillus versicolor N2bc.
Yan Meng-Xia,Mao Wen-Jun,Liu Xue,Wang Shu-Yao,Xia Zheng,Cao Su-Jian,Li Jing,Qin Ling,Xian Hua-Li
Carbohydrate polymers
An extracellular polysaccharide, N1, was obtained from the culture medium of the deep-sea fungus Aspergillus versicolor N2bc by a combination of ethanol precipitation, ion-exchange and gel filtration chromatography. N1 was a mannoglucogalactan with molecular weight of about 20.5kDa. Results of chemical and spectroscopic analyses, including Fourier-transform infrared, one- and two-dimensional nuclear magnetic resonance spectroscopy showed that the main chain of N1 consisted of →2)-α-d-Glcp-(1→, →2)-β-d-Glcp-(1→ and →6)-β-d-Manp-(1→ units, substituted at C-6 position of →2)-α-d-Glcp-(1→ units. The branches were composed of galactofuranose-oligosaccharides built up of →5)-β-d-Galf-(1→, →6)-β-d-Galf-(1→ and terminal β-d-Galf units. At an average, there were two branching points for every five sugar residues in the backbone. N1 possessed a high in vitro antioxidant activity as evaluated by scavenging assays involving superoxide, 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radicals and reducing power. The investigation revealed that N1 was a novel antioxidant polysaccharide differing from previously described extracellular polysaccharides and could be a potential antioxidant.
10.1016/j.carbpol.2016.03.090
Structural characterization and anticancer activity of cell-bound exopolysaccharide from Lactobacillus helveticus MB2-1.
Li Wei,Xia Xiudong,Tang Weizhi,Ji Juan,Rui Xin,Chen Xiaohong,Jiang Mei,Zhou Jianzhong,Zhang Qiuqin,Dong Mingsheng
Journal of agricultural and food chemistry
A novel cell-bound exopolysaccharide (c-EPS) was isolated from Lactobacillus helveticus MB2-1 by ultrasonic extraction, anion exchange, and gel filtration chromatography before being structurally characterized. The c-EPS is a heteropolysaccharide with an average molecular weight of 1.83 × 10(5) Da and is composed of glucose, mannose, galactose, rhamnose, and arabinose at a molar ratio of 3.12:1.01:1.00:0.18:0.16. Methylation analysis and nuclear magnetic resonance analysis revealed that the c-EPS is a linear glucomannogalactan containing repeating units of → 6)-β-D-Manp-(1 → 3)-β-D-Glcp-(1 → 3)-β-D-Glcp-(1 → 3)-β-D-Glcp-(1 → 4)-α-D-Galp-(1 → and trace amounts of Rhap-(1 → and (1 → 4)-Arap residues. Complex formation with Congo red demonstrated a triple-strand helical conformation for the c-EPS. Scanning electron microscopy of the c-EPS revealed many regular feather-like structural units. Topographical examination of c-EPS by atomic force microscopy revealed that the c-EPS formed rounded-to-spherical lumps with different sizes and chain formations. Furthermore, preliminary in vitro tests revealed that c-EPS significantly inhibited the proliferation of HepG-2, BGC-823, and especially HT-29 cancer cells.
10.1021/acs.jafc.5b01086
Rhelogical, dermal wound healing and in vitro antioxidant properties of exopolysaccharide hydrogel from Pseudomonas stutzeri AS22.
Maalej Hana,Moalla Dorsaf,Boisset Claire,Bardaa Sana,Ben Ayed Hanen,Sahnoun Zouheir,Rebai Tarek,Nasri Moncef,Hmidet Noomen
Colloids and surfaces. B, Biointerfaces
The in vitro antioxidant activity and the in vivo wound healing performance of the exopolysaccharide EPS22, produced by Pseudomonas stutzeri AS22, were investigated. Antioxidant activity was evaluated by three different tests. The scavenging effect on DPPH radicals at a concentration of 1mg/ml was 80±1.41%. The reducing power reached a maximum of 1.26±0.02 at 2 mg/ml. Moreover, EPS22 showed good chelating ability and chelated almost 88.5±0.7% of ferrous ions at 0.75 mg/ml. The rheological characterization of EPS22 gel (0.5%) showed a pseudoplastic behavior, high elasticity, good mechanical strength and stability with high water-absorption ability. The application of the EPS22 gel on dermal full-thickness excision wounds in a rat model every two days, enhanced significantly wound healing activity and a total closure was achieved after 12 days of wound induction. Further, histological examination of biopsies showed advanced tissue regeneration, characterized by the presence of well-organized stratum of both derma and epidermis.
10.1016/j.colsurfb.2014.10.017
Rheological properties of phosphorylated exopolysaccharide produced by Sporidiobolus pararoseus JD-2.
Han Mei,Du Chao,Xu Zhi-Yuan,Qian He,Zhang Wei-Guo
International journal of biological macromolecules
The exopolysaccharide (EPS) produced by Sporidiobolus pararoseus JD-2 contained about 2.0% phosphorus and its zeta potential was -30mV at pH 6.0. This indicated that it was an anionic polymer. In steady shear measurements, there was a Newtonian plateau in low shear rates, but power-law behavior exhibited at high shear rates. So Williamson model was used to study the flow character of the EPS solutions. This phenomenon was according to its high molecular weight and entanglement networks. Considering the EPS was an anionic polymer, the influence of added salts on apparent viscosity of EPS were studied. Different NaCl concentrations had little effect on the viscosity of the EPS, but high concentrations of CaCl2 increased the viscosity of EPS significantly. EPS solutions showed inapparent thixotropic properties in stress growth and thixotropic loop experiment. According to the flow curve results and oscillatory shear results obtained, the rheological properties of EPS solutions were closer to that of entanglement network system, like carboxy methyl cellulose rather than weak gel structure such as xanthan gum. The EPS had the function to enhance immunological functions. Understanding the rheological characteristics of EPS was essential to exploit the functionality of this EPS in different food or medicine systems.
10.1016/j.ijbiomac.2016.04.035
Production, structural characterization and gel forming property of a new exopolysaccharide produced by Agrobacterium HX1126 using glycerol or d-mannitol as substrate.
Liu Yongmei,Gu Qiuya,Ofosu Fred Kwame,Yu Xiaobin
Carbohydrate polymers
A strain Agrobacterium HX1126 was isolated from soil sample near the canal in Wuxi. Glycerol was used as carbon source for the production of a new exopolysaccharide which was named PGHX. PGHX composed mainly of galactose, with lower amounts of arabinose and aminogalactose. It was found that this strain could use d-mannitol as carbon source to produce PGHX too. A method for the preparation of crude PGHX was proposed and the crude PGHX can be formed in a gel formation when 30 g/L was put into the boiling water for 10 min, with an achieved gel strength of 957 g/cm(2). The concentration of proteins in the crude product was considered to be an important parameter which directly influence the gel forming property. The highest production of PGHX (24.9 g/L) was obtained under the nitrogen depletion condition. The structure of the product was confirmed by NMR and FTIR.
10.1016/j.carbpol.2015.09.107
Isolation, structure, and potential biotechnological applications of the exopolysaccharide from Paenibacillus polymyxa 92.
Grinev Vyacheslav S,Tregubova Kristina V,Anis'kov Alexander A,Sigida Elena N,Shirokov Alexander A,Fedonenko Yulia P,Yegorenkova Irina V
Carbohydrate polymers
Paenibacillus polymyxa 92, isolated from wheat roots, produced large amounts (38.4 g L) of exopolysaccharide (EPS) in a liquid nutrient medium containing 10 % (w/v) sucrose. The EPS was precipitated from the culture broth with cold acetone and was purified by gel filtration and anion-exchange chromatography. The molecular mass of the EPS was 2.29-1.10 × 10 Da. Diffuse reflectance infrared Fourier transform and nuclear magnetic resonance spectra showed that the EPS was a linear β-(2→6)-linked fructan (levan). Aqueous EPS solutions showed pseudoplastic behavior when shear stress was applied at different temperatures. By using the Ostwald-de Waele model, the rheological characteristics of the EPS solution were ascertained. The sorption capacity of the EPS for Zn(II), Cd(II), Pb(II), and Cu(II) was investigated. Sorption was maximal (q = 481 mg g) for Cu(II) ions. In model experiments, treatment of wheat seeds with EPS solution significantly increased the length of seedling roots and shoots.
10.1016/j.carbpol.2019.115780
Exopolysaccharide produced by the potential probiotic Lactococcus garvieae C47: Structural characteristics, rheological properties, bioactivities and impact on fermented camel milk.
Ayyash Mutamed,Abu-Jdayil Basim,Itsaranuwat Pariyaporn,Almazrouei Noora,Galiwango Emmanuel,Esposito Gennaro,Hunashal Yamanappa,Hamed Fathalla,Najjar Zein
Food chemistry
Fermented camel milk possesses a weak (liquid-like) gel structure. We aimed to 1) investigate the characteristics, bioactivities and rheological properties of the exopolysaccharide (EPS) produced by Lactococcus garvieae-C47 (exopolysaccharide-C47 product), a potential probiotic bacterium, on milk extracted from camels and 2) examine the rheological properties of the fermented camel milk produced by L. garvieae-C47. Exopolysaccharide-C47 product (molecular weight: 7.3 × 10 Da) was composed of the following monosaccharides: glucose (82.51%), arabinose (5.32%) and xylose (12.17%). The antioxidant, antitumor and α-amylase inhibitory activities of exopolysaccharide-C47 product reached up to 67.52, 59.35 and 91.0%, respectively. The apparent viscosity of exopolysaccharide-C47 product decreased with the increase in shear rate and declined by increasing the temperature up to 50 °C. The rheological properties of exopolysaccharide-C47 product are influenced by the salt type and pH value. The exopolysaccharide product produced by L. garvieae C47 possesses valuable health benefits and has the ability to improve the weak structure of fermented camel milk.
10.1016/j.foodchem.2020.127418
A Relation between Exopolysaccharide from Lactic Acid Bacteria and Properties of Fermentation Induced Soybean Protein Gels.
Yang Xiaoyu,Feng Jiao,Zhu Qianqian,Hong Rui,Li Liang
Polymers
Exopolysaccharide (EPS) producing lactic acid bacteria (LAB) is considered to be an effective texture improver. The effect of LAB strains (different EPS production capacity) on physicochemical properties (texture profile, water distribution, rheological properties, and microstructure), protein conformation, and chemical forces of soybean protein gel was investigated. Correlations between EPS yield and gel properties were established. Large masses of EPS were isolated from fermentation gel (-G, 677.01 ± 19.82 mg/kg). Gel with the highest hardness (319.74 ± 9.98 g) and water holding capacity (WHC, 87.74 ± 2.00%) was also formed with . The conversion of β-sheet to α-helix, the increased hydrophobic interaction and ionic bond helped to form an ordered gel network. The yield was positively correlated with hardness, WHC, A, viscoelasticity, and viscosity, but negatively correlated with A ( < 0.05). The macromolecular properties of EPS (especially the yield) and its incompatibility with proteins could be explained as the main reason for improving gel properties. In conclusion, the EPS producing LAB, especially used in our study, is the best ordinary coagulate replacement in soybean-based products.
10.3390/polym14010090