Production and Characterization of Melanin by Submerged Culture of Culinary and Medicinal Fungi Auricularia auricula

Abstract

Natural melanin is of great potential value and application in the fields of pharmacology, cosmetics, and functional foods. In the present study, statistically designed experiments were conducted for the optimization of the media to enhance the production of melanin by submerged culture of Auricularia auricula. Glucose, tyrosine, peptone, and CaCO3 were found to have significant effects (P < 0.015) on melanin biosynthesis by a Plackett-Burman experimental design and subsequently optimized using response surface methodology. Optimal media were obtained at the following concentrations: glucose, 0.90 g/L; tyrosine, 6.68 g/L; peptone, 6.99 g/L; and CaCO3, 6.75 g/L. The validity of the optimum media was verified in separate experiments in which the melanin yield of 1008.08 mg/L was obtained under optimum conditions, compared with 306.52 mg/L at other conditions, i.e., a 3.29-fold increase. Furthermore, the important physical and chemical properties of A. auricula melanin were determined. The findings from the present study indicate that large-scale production of natural melanin by submerged culture of A. auricular could be a useful approach.

Purification and characterisation of a sulphur rich melanin from edible mushroom Termitomyces albuminosus Heim

“…The linear decrease in the absorption with increasing wavelength was observed for Termitomyces melanin similar to that reported by (Zhang et al 2015). Absorption peaks in UV regions occur due to the presence of many conjugated structures in melanin molecule (Ou-Yang et al 2004).…”

“…The log of optical density of a melanin solution when plotted against wavelength produces a linear curve with negative slopes. Such characteristic straight lines with negative slopes have been obtained from some melanogenic fungi such as Phyllosticta capitalensis and Auricularia auricula with slope ranging −0.0015 to −0.0030 (Ellis and Griffiths 1974; Suryanarayanan et al 2004; Bin et al 2012; Zhang et al 2015). The slopes of linear plots are often used to identify melanins and matching spectral features in the present work confirms the identity of T. albuminosus melanin.…”

“…Previously (Siddiquee et al 2012, 2015) reported dark grey to black colouration in T. heimii and T. aurantiacus culture grown on Potato Dextrose Agar medium after 7 days but failed to identify the melanogenesis process. Zhang et al (2015) reported melanin from culture free filtrate of Auricularia auricula in submerged culture conditions yielding 0.124–0.558 g/L. However, Sun et al (2016b) reported yield of 2.22 g/L melanin in culture filtrate of A. auricula in complete medium containing lactose, yeast extract, tyrosine, calcium chloride and sodium chloride, but not estimated melanin bound to cultural biomass.…”

“…Exo- and endomelanin complex of Inonotus obliquus and Phellinus robustus in submerged conditions demonstrate high-antioxidant and genoprotective properties (Bisko et al 2002, 2007). Melanin in Auricularia auricula has been studied extensively (Zou et al 2010; Bin et al 2012; Zhang et al 2015; Sun et al 2016a). Melanin is found useful in the field of material science as coating material in electronic/bioelectronics, drug delivery and cosmetics as sunscreens, emphasising the importance of finding good, non-toxic melanin sources (Blumenberg 2017).…”

Production of Melanin Pigment by Fungi and Its Biotechnological Applications

“…Several studies have shown that the composition of the growth medium, nature and concentration of carbon and nitrogen sources, minerals, vitamins, temperature, pH, the presence of Melanin 50 oxygen and aeration, light, stress, and irradiation, among others, affect the growth and pigment production in fungi and that the manipulation of the culture conditions can result in enhanced pigment production [41][42][43][44][45][46][47].…”