Guo Jing, Rao Zhiming, Yang Taowei, Man Zaiwei, Xu Meijuan, Zhang Xian
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China; The Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China.
FEMS Microbiol Lett. 2014 Aug;357(1):85-91. doi: 10.1111/1574-6968.12497. Epub 2014 Jun 27.
Forty-five bacterial strains that produced diffusive pigments were isolated from 40 soil samples. Maximum pigment production was from a Streptomyces kathirae strain designated SC-1. The diffused pigment was characterized by UV-visual and infrared spectroscopy, MS and (1) H nuclear magnetic resonance imaging, and was confirmed as melanin. This may be the first report of melanin production by S. kathirae. To enhance melanin production, the culture medium was optimized by conducting a series of batch fermentations in a defined medium, and the results were analysed statistically using a response surface method. The optimal culture medium comprised 3.3 g L(-1) amylodextrine, 37 g L(-1) yeast extract, 5 g L(-1) NaCl, 0.1 g L(-1) CaCl2 and 54.4 μM CuSO4 . The pH of this medium was 6.0. Under optimal conditions, the melanin concentration was maximized at 13.7 g L(-1) , c. 8.6-fold higher than obtained in suboptimal medium. To our knowledge, the results provide novel data on melanin fermentation, and identify an excellent candidate for industrial-scale microbial fermentation of melanin.
从40份土壤样品中分离出45株产生扩散性色素的细菌菌株。色素产量最高的是一株名为SC-1的卡氏链霉菌。通过紫外可见光谱、红外光谱、质谱和氢核磁共振成像对扩散性色素进行了表征，并确认为黑色素。这可能是关于卡氏链霉菌产生黑色素的首次报道。为了提高黑色素产量，在限定培养基中进行了一系列分批发酵以优化培养基，并使用响应面法对结果进行统计分析。最佳培养基包含3.3 g L(-1) 支链淀粉、37 g L(-1) 酵母提取物、5 g L(-1) NaCl、0.1 g L(-1) CaCl2和54.4 μM CuSO4。该培养基的pH值为6.0。在最佳条件下，黑色素浓度最高可达13.7 g L(-1)，约比次优培养基中的产量高8.6倍。据我们所知，这些结果提供了关于黑色素发酵的新数据，并确定了一种用于黑色素工业规模微生物发酵的优秀候选菌株。
