The study of fermentation conditions of the natural melanin
Abstract: This article study the colonial morphology, cell characteristics, growth medium, melanin synthesis of the melanin-producing strain which get from the desert in Ningxia. The results show that culture in czapek medium,the mycelium is white in early, mycelium combined with medium closely, culturing post,the mycelium secret a lot of melanin and the colony become fold. In order to improve the production of melanin as much as possible,the conditions of fermentation were optimized, the results show that the optimal fermentation conditions were: sucrose 50 g / L, NaNO3 3 g / L, K2HPO4·3H2O 1g / L, KCl 0.5g / L, MgSO4·7H2O 0.5g / L , water 1000ml.Culturing under the conditions of 28℃ and 180 r/m, crude extracts of melanin up to 2.56g/L. On this basis,studying the physical and chemical properties of melanin which carried out by the fermentation, the results show that the melanin has good stability under UV and good antiagent activity,it also has some antioxidant activity,but it is not very stable under high temperature and daylight.
Keywords：Melanin; fermentation; Optimization; physical and chemical properties
