链霉菌G-HD-4产黑色素发酵条件的优化

Optimal Fermentation Conditions for Melanin Production by Streptomyces G-HD-4

为提高链霉菌G-HD-4的黑色素产生量,以L-酪氨酸为底物,对该菌种产黑色素的工艺条件进行研究,通过单因素试验和均匀设计试验,得到最佳产黑色素的发酵条件为:马铃薯15g/100mL、乳糖2.5g/100mL、干酪素2.07g/100mL、MgSO40.11g/100mL、KH2PO40.25g/100mL、L-酪氨酸0.25g/100mL、以接种量为6%(体积分数),培养基起始pH值为6.0,装液量为25mL,28℃,150r/min振荡培养5d,黑色素产量可达(13.4±0.05)g/L,比在基础培养基中的黑色素产量(5.78g/L)提高约2.3倍。

In order to improve melanin production by Streptomyces G-HD-4 fermentation, the optimal conditions for fermenting L-tyrosine by this strain were investigate by single factor and uniform design methods. The optimal medium compositions （on the basis of 100 mL medium） were 15 g potato, 2.5 g lactose, 2.07 g casein, 0.25 g KH2PO4, 0.11 g MgSO4, and 0.25 g L-tyrosine. The optimal fermentation process was that 25 mL of medium was contained in a 250 mL flask for 5-day fermentation at initial pH 6.0, 28 ℃ and 150 r/min shaking speed. As a result, the maximum melanin yield reached up to （13.4 ± 0.05） g/L, approximately 2.3 times higher than that obtained using preoptimization fermentation medium.