【摘要】 从土壤筛中筛选分离获得1株γ-聚谷氨酸合成菌Bacillus subtilis PGS-1,在富含谷氨酸和葡萄糖的培养基中可大量合成γ-聚谷氨酸,与大多文献报道的微生物合成的γ-聚谷氨酸相比,具有较低的分子量(300ku～400ku)和较窄的分子量分布,可适用于低分子量要求的医药、化妆品和水处理等应用领域,值得深入开发研究。为提高γ-聚谷氨酸的发酵产量,对Bacillus subtilis PGS-1的摇瓶培养基条件进行了响应面优化,确定了影响γ-PGA合成的显著因素依次为谷氨酸、葡萄糖和(NH4)2SO4;在优化条件下,γ-聚谷氨酸产量达26g/L,较优化前提高了44%。更多还原

【Abstract】 A novel γ-polyglutamic acid(γ-PGA) producing strain Bacillus subtilis PGS-1 was isolated from soil,which could produce a large amount of γ-PGA in the medium containing glucose and glutamate.Compared with other reported biosynthetic γ-PGA,a lower molecular weight(300ku~400ku) and a narrow polydispersity endowed γ-PGA derived from Bacillus subtilis PGS-1 a promising application,such as in the drug delivery system,cosmetic and water treatment.To achieve an efficient production of γ-PGA,the flask culture medium was optimized by response surface analysis.The experimental results showed that L-glutamate and glucose were the most important factors to the γ-PGA synthesis,and ammonium sulfate was secondly important.Under this conditions,the yield of γ-PGA reached 26g/L,which increased by 44% compared with γ-PGA yield without optimization.更多还原