Institute of Bioengineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, People's Republic of China.
Appl Biochem Biotechnol. 2010 Jan;160(2):370-7. doi: 10.1007/s12010-008-8307-z. Epub 2008 Jul 31.
Poly-gamma-glutamic acid (gamma-PGA) is a kind of water-soluble and biodegradable polymer made from D- and L-glutamic acid units, which are linked by amide bonds formed between alpha-amino and gamma-carboxylic acid groups. As a potential targeted biopolymer that can be refined from biomass directly, gamma-PGA has been increasingly applied to food, cosmetic, and pharmaceutical industries. In this work, a suitable nitrogen source was screened out for the high and cost-effective production of gamma-PGA in Bacillus subtilis ZJU-7. The effects of inoculation time and initial glucose concentration on the gamma-PGA production were investigated systematically in both shake flasks and a bench-top 15-l fermentor. Under the optimized culture conditions, a high gamma-PGA productivity (46.4 g/l) was obtained after 48 h cultivation at 37 degrees C. Finally, the large-scale fermentation of gamma-PGA production was successfully scaled up to a 100-l fermentor, with the highest gamma-PGA productivity for over 54.0 g/l.
聚-γ-谷氨酸（γ-PGA）是一种由 D-和 L-谷氨酸单元组成的水溶性和可生物降解聚合物，这些单元通过 α-氨基和 γ-羧酸基团之间形成的酰胺键连接。作为一种可以直接从生物质中提取的潜在靶向生物聚合物，γ-PGA 已经越来越多地应用于食品、化妆品和制药行业。在这项工作中，筛选出了一种合适的氮源，用于枯草芽孢杆菌 ZJU-7 中高效且经济地生产 γ-PGA。在摇瓶和台式 15 升发酵罐中系统地研究了接种时间和初始葡萄糖浓度对 γ-PGA 生产的影响。在优化的培养条件下，在 37°C 下培养 48 小时后，获得了 46.4 g/L 的高 γ-PGA 生产率。最后，γ-PGA 的大规模发酵成功扩大到 100 升发酵罐，γ-PGA 的最高生产率超过 54.0 g/L。
