降解亚硝酸盐乳酸菌的筛选及鉴定

Screening and identification of lactic acid bacteria degrading nitrite

以家制的大豆酱、酸菜、酱黄瓜、生拌黄瓜、腌制芥菜以及市售的辣白菜、乌江榨菜、五原榨菜、咸萝卜块为来源,从中分离出了18株乳酸菌菌株。经测定其在MRS液体培养基中降解亚硝酸盐的能力,最终从家制发酵的大豆酱中筛选出了1株优良的亚硝酸盐降解菌Dj-1,其在1.0×107cfu/mL时,对0.125mg/mL亚硝酸盐22h内降解率为93.63%。经过形态特征观察、生理生化试验和16S rRNA基因序列相似性分析,鉴定该菌株为屎肠球菌。

18 lactic acid bacteria strains were separated from doenjang juice, fermented Chinese cabbage juice, pickled cucumber juice, fresh salt- ed-cucumber juice and sauced-mustard juice of homemade and pungent cabbage juice, wujiang pickled mustard juice, wuyuan pickled mustard juice and pickled radish juice of supermarket. A strain of lactic acid bacteria named Dj-1 was screened fi：om homemade doenjang, which had the strongest ability to degrade nitrite. When grown in 0.125mg/ml nitrite sodium added medium, 1.0×10^7cfu/ml of Dj-1 could degrade 93.63% nitrite sodium dur- ing 22h fermentation. The strain was identified Enterococcus faecium on the base of characteristics, physiology and biochemistry and 16S rRNA gene sequence similarity analysis.