以乳酸菌作为出发菌株,将其接入豆浆(大豆∶水=1∶8)进行发酵,根据发酵过程中γ-氨基丁酸(GABA)产量,筛选出GABA的高产乳酸菌菌株,然后利用紫外线对高产菌株进行诱变处理,筛选得到稳定高产GABA突变菌株.结果表明,保加利亚乳杆菌L2为高产GABA乳酸菌菌株.GABA产量达到1.066 g·L-1.对L2进行紫外诱变处理的最佳照射时间为50 s,在此照射时间下,获得高产GABA突变菌株L2-4,其在含有1％ L-谷氨酸的改良MRS培养基和豆浆中的GABA产量分别为4.235和1.394g·L-1,比原菌株的GABA产量分别提高了25.63％和30.77％.%Soya-bean milk (soybean: water=1: 8) were fermented by Lactobac/l/us. High-yield GABA strain was screened according to the y-aminobuyric acid (GABA) accumulation amount during soya-bean milk fermentation. The high-yield GABA stable mutant strain was obtained by ultraviolet mutagenesis. The results showed that Lactobacillus bulgaricus L2 was high-yield GABA strain by the screening of GABA-yield Lactobacillus, GABA yield reached 1.066 g·L'. The optimum mutagenesis time of L2 by ultraviolet was 50 s. In this condition, a high-yield GABA stable mutant strain named L2-4 was obtained, and the GABA yields were 4.235 g·L' in reformed MRS (containing 1% L-glutamic acid) and rn1.394 g·L-1 in soya-bean milk. Compared to the Initial strain, GABA yield of mutant strain increased 25.63% in reformed MRS (containing 1% L-glutamic acid) and 30.77% in soya-bean milk.
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