水果表面高产γ-氨基丁酸酵母菌菌株的筛选、鉴定和发酵条件优化

Screening of a high yield γ-aminobutyric acid yeast from the fruit surface and optimization of its cultural conditions

从水果表面分离筛选到1株相对高产γ-氨基丁酸(GABA)的酵母菌菌株MJ2,经初步鉴定该菌株为啤酒酵母(Saccharomyces cerevisiae)。对菌株MJ2的发酵培养基和发酵条件用单因素轮换试验和正交试验进行整体优化。结果表明菌株MJ2转化富集GABA的适宜条件为:以可溶性淀粉为碳源、牛肉膏为氮源,初始pH5.5、培养温度31℃、摇床速度180 r/min时,发酵培养3 d,发酵液中GABA的产量最高可达7.539 g/L。

A strain of yeast producd γ-aminobutyic acid （GABA） was isolated from the fruit surface. The selected yeast （MJ2） was identified as Saccharomyces cerevisiae according to the morphology and biochemistry. The culture substrate and fermentation conditions of MJ2 were optimized by single factor experiment and L9 （34 ） orthogonal test. The results showed that the optimum conditions of GABA produced from the yeast （MJ2） were soluble starch as carbon source, beef paste as nitrogen source, pH 5.5 at the begirming of the culture,31℃ of culture temperature, 180 r/min of shaking speed. The content of GABA was 7. 539 g/L in the optimum cuhure conditions.