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Scalable Biosynthesis of Melanin by the Basidiomycete Armillaria cepistipes. Ribera Javier,Panzarasa Guido,Stobbe Annika,Osypova Alina,Rupper Patrick,Klose Daniel,Schwarze Francis W M R Journal of agricultural and food chemistry Natural melanin features many interesting properties, including the ability to shield electromagnetic radiation, the ability to act as scavenger for radical and reactive oxygen species and the capacity to chelate different metal ions. For these reasons, melanin is becoming increasingly relevant for the development of functional materials with potential applications in cosmetics, drug delivery, and water purification. However, the extraction and purification of melanin from conventional sources (e.g., sepia ink, hair, and wool) is inefficient and not easily scalable, hence diverting its technological applications. Some fungal species, especially wood-decay basidiomycetes, can be regarded as promising sources of melanin. In the present study, we screened different fungi in regard to their melanin-biosynthesis abilities using l-tyrosine as a precursor, and we found that an Armillaria cepistipes strain (Empa 655) produced the highest yield of melanin (27.98 g L). Physicochemical characterization of the obtained fungal melanin revealed a typical eumelanin structure. The method for the biosynthesis of fungal melanin we propose is efficient, scalable, and sustainable and has the potential to provide support for further technological exploitation. 10.1021/acs.jafc.8b05071
Characterization of the physicochemical properties and extraction optimization of natural melanin from Inonotus hispidus mushroom. Hou Ruolin,Liu Xin,Xiang Kaikai,Chen Liangtao,Wu Xiaoping,Lin Wenxiong,Zheng Mingfeng,Fu Junsheng Food chemistry In this study, solid-state fermentation was used to produce Inonotus hispidus melanin (IH melanin). Its physicochemical properties were characterized, and ultrasonic-assisted extraction was used to optimize its extraction process. Characterization techniques like elemental analysis and so on were used to identify melanin. The solubility, stability, and antioxidant activity were also measured. Furthermore, the extraction process of IH melanin was optimized. The results showed that the pigment could be defined as dihydroxy phenylalanine (DOPA)-melanin, it displayed irregular spherical and ellipsoidal structures with average size of 89.33 nm. Melanin has a specific stability and shows antioxidant activity. The optimal extraction parameters of melanin were a NaOH concentration of 0.56 mol/L, solid-liquid ratio of 1:50, ultrasonic power of 300 W, extraction temperature of 70 °C, and ultrasonic time of 70 min. This study was the first time that IH melanin was obtained. The results may be applied to health food or food additives. 10.1016/j.foodchem.2018.11.002