The Screening Of The High-Melanin-Producing Strains And Studies On The Fermentation And The Sturcture Of The Melanin

The strains isolated from the soil were screened according the ability of melanin-producing and 27 strains were acquired among which there were 4 high-melanin-production strains. The fermentation condition of the strain No.88 was studied , the culture medium and the culture condition were confirmed. The melanin produced by the strain No.88 was concluded to be consisted of 11 components according to the preliminary study of this melanin and 8 of whose molecule formula were speculated.4 strains who produce extracellular melanin were acquired after the screening among the 321 strains isolated from the soil and strain No.88 was confirmed as the high-melanin-producing strain according the ability of melanin-producing on different culture mediums. The strain No.88 was confirmed to be streptomyces according the morphological, physiological and chemical characters. Because of its high-melanin-production, the strain No.88 may be a new kind of strain source in the melanin-producing microbe.A series of experiments were designed to study the effect of the pH, Na⁺, Mg⁺, (NH₄)⁺, peptone, glucose, tyrosine to themelanin-production. The best culture medium was determined and the best culture condition was confirmed after the culture condition optimizing.The melanin was isolated from the fermentation mixture of the strain No.88. After purification by the means of extraction, folium separation, silica gel column separation, HPLC, the ESI-MS detect was hold and the melanin was determined to be consist of 11 components and the HR-MS was hold to detect each of those components. The molecular formulas of 8 of those components were speculated according the correlative literatures on the structure of the natural melanin.