寒地黑土中产γ-氨基丁酸乳酸菌筛选及发酵培养基优化

Screening and Fermentation Medium Optimization of Lactobacillus γ-aminobutyrate in Black Soil of Cold Region

利用MRS培养基分别从牡丹江、漠河、五常的寒地黑土中筛选产γ-氨基丁酸(GABA)的乳酸菌菌株,对其做形态学观察和生理生化鉴定,并进行了发酵培养基组成的优化实验,分析比较不同碳源、氮源、碳氮比、初始p H和L-谷氨酸浓度对产GABA的影响。结果表明:共筛出五株菌株,分别编号为SbO001、SbO002、SbO003、SbO004、SbO005,可以将五株菌株初步鉴定为链球菌科(Streptococcaceae)。当发酵培养基组分碳源为葡萄糖,氮源为硫酸铵,碳氮比1∶1,初始pH为5.5,底物为1%的L-谷氨酸时,菌株产GABA的能力较好,为1.112 g/L。本实验将为寒地黑土中产GABA乳酸菌的筛选提供一定的理论依据。

The lactic acid bacteria producing γ-aminobutyric acid( GABA) strains were screened from the black soil of Mudanjiang,Mohe and Wuchang by MRS medium,and their morphological observation,physiological and biochemical identification were carried out,and the fermentation medium composition was optimized.Experiments were performed to analyze the effects of different carbon sources,nitrogen sources,carbon to nitrogen ratios,initial p H and L-glutamic acid concentration on GABA production. The results showed that five strains were examined,which were numbered SbO001,SbO002,SbO003,SbO004 and SbO005. Five strains could be initially identified as Streptococcaceae.When the carbon source of fermentation medium was glucose,the nitrogen source was ammonium sulfate,the carbon-nitrogen ratio was 1∶ 1,the initial p H was 5.5,and the substrate was 1% l-glutamic acid,the strain had a good gaba-producing capacity of 1.112 g/L.This experiment will provide some theoretical basis for the screening of lactobacillus GABA in the middle black soil of the cold region.