贝莱斯芽孢杆菌PG1-2生产γ-聚谷氨酸的发酵培养基和培养条件优化

Optimization of Fermentation Medium and Conditions of γ-poly-glutamic Acid Production by Bacillus velezensis PG1-2

本项目从自然界中筛选得到了能够生产γ-聚谷氨酸(PGA)的贝莱斯芽孢杆菌(Bacillus velezensis)PG1-2,对其发酵培养基和发酵条件进行优化,并对其发酵过程进行了研究。PG1-2合成PGA的最佳碳源为蔗糖,最佳氮源为酵母粉和蛋白胨。PG1-2合成PGA的最佳条件为:蔗糖用量为80 g/L,氮源用量为20 g/L,谷氨酸钠用量60 g/L,发酵pH值为6.8,通气量1 vvm,搅拌转速350 r/min。在最佳发酵条件下,PGA的产量可以达到33.8 g/L。贝莱斯芽孢杆菌PG1-2能够高产PGA,为其在农业及PGA生产上的应用提供了更多可能。

In present work,Bacillus velezensis PG1-2 producing PGA was isolated from natural soil and the fermentation medium and conditions were optimized.The best carbon source of PGA production was sucrose,and the best nitrogen source was mixture of yeast extract and peptone.The results of present work indicated that PG1-2 produces maximum PGA of 33.8 g/L when sucrose of 80 g/L,nitrogen source of 20 g/L,glutamic acid sodium of60 g/L,pH value of 6.8,throughput of 1 vvm and agitator speed of 350 r/min.B.velezensis PG1-2 could produce PGA of high yield,indicating its application value in agriculture and PGA production.