Strains producing gamma-aminobutyric acid(GABA)are screened and identified from Yingcheng radish pickles and their fermentation conditions are optimized.45 strains of Lactobacillus were screened by dilution coated plate method and streak separation method,and 7 strains of GABA-producing bacteria were qualitatively screened by thin layer chromatography.The Lactobacillus LS-23 with high GABA yield was selected by high performance liquid chromatography,and its yield was 1.039 mg/mL.The strain was identified as Lactobacillus plantarum by morphological characteristics,physiological and biochemical characteristics and 16S rDNA sequence homology analysis.The strain was positive for Gram staining and negative for indole and contase tests.The lowest acidity of fermentation broth was 3.565 at 24 h,and the logarithmic growth stage was 4-18 h.Based on the growth amount of bacteria and the content of GABA in fermentation liquor,the optimal carbon source and nitrogen source of the strain were fructose and yeast paste,respectively.This study laid a theoretical foundation for the yield optimization of GABA-producing lactic acid bacteria.
关键词
γ-氨基丁酸/植物乳杆菌/筛选/分子鉴定/生理生化试验
Key words
γ-aminobutyric acid/Lactobacillus plantarum/screening/molecular identification/physiological and biochemical tests
维普
万方数据