枯草芽孢杆菌发酵生产聚-γ-谷氨酸的条件优化

摘要

为提高聚-γ-谷氨酸(poly-γ-glutamic acid,γ-PGA)产量,降低其生产成本,利用枯草芽孢杆菌(Bacillus subtilis),采用单因素试验及正交试验优化法,探究培养基组分及发酵条件对γ-PGA发酵产量的影响.结果表明:最佳培养基组成和培养条件为:蔗糖5%,谷氨酸钠6%,氯化铵0.3%,磷酸氢二钾2%,磷酸二氢钾0.1%,硫酸锰0.003%,pH 7.0,接种量为3%,发酵温度33℃,发酵时间48 h.与未优化前γ-PGA产量(15.8 g/L)相比,经优化后的产量达20.8 g/L,提高了31.65%.%To improve the production and reduce the cost ofγ-PGA, a fermentation study with Bacillus subtilis was conducted to explore the effects of medium compositions and culture conditions onγ-PGA production based on single-factor experiment and orthogonal design. The results showed that the optimized cultivation conditions and medium composition were as follows:sucrose 5%;sodium glutamate 6%;NH4Cl 0.3%;K2HPO42%;KH2PO40.1%;MnSO40.003%;initial pH 7.0;inoculum amount 3%;temperature 33℃;fermentation time 48 h. In this study, highγ-PGA productivity (20.8 g/L) was obtained under the optimal conditions, 31.65%higher than the previous conditions(15.8 g/L).