碳氮源对Bacillus sp.B_(53)发酵产聚谷氨酸的影响

考察了 8种不同碳源和 7种不同氮源对Bacillussp B53 发酵产聚谷氨酸的影响。结果表明 ,柠檬酸、甘油和硫酸铵是合成聚γ 谷氨酸比较适宜的碳源和氮源 ,前体物质L 谷氨酸的存在是聚谷氨酸高产所必需的。经过正交试验和回归分析 ,确定最佳碳氮源配比为 :L Glu 2 0 g/L ,CTA 9 86 4g/L ,Glycerol 80 36 g/L ,(NH4) 2 SO47g/L ,其他培养基成分有MgSO4·7H2 O 0 5 g/L ,FeCl3 ·6H2 O 0 0 2 g/L ,K2 HPO41g/L ,CaCl2 ·2H2 O0 2 g/L ,MnSO4·H2 O 0 0 5 g/L。在既定发酵条件下 ,Bacillussp B53 在优化培养基上产生γ PGA 19 12 g/L比基础发酵培养上的 8 87g/L提高了 115 5 6 %。

Effects of Carbon Source and Nitrogen Source on Production of Poly(γ-glutamic acid) by Bacillus sp. B53

The effects of 8 carbon sources and 7 nitrogen sources on the production of poly(γ-glutamic acid) were investigated. The results showed that the production of γ-PGA was different on various carbon sources and nitrogen sources.Among these sources, citric acid,glycerol and ammonium sulfate were better carbon and nitrogen sourcos. L-glutamic acid was needed in the course of γ-PGA overproduction. Using orthogonal experimental design and regression analysis, the optimum fermentation medium was obtained. It contained(g/L): citric acid 9.864, glycerol 80.36, L-glutamic acid 20, (NH 4) 2SO 4 7,MgSO 4·7H 2O 0.5,FeCl 3·6H 2O 0.02,K 2HPO 4 1,CaCl 2·2H 2O 0.2,MnSO 4·H 2O 0.05 g. The γ-PGA production by Bacillus sp. B 53 was increased by 115.56%, from 8.87 g/L to 19.12 g/L when the strain was cultivated in the optimal medium as compared to the basal medium.