腌制食品中降解亚硝酸盐的乳酸菌分离与鉴定

Isolation and identification of nitrite-degrading lactic acid bacteria from traditional pickled vegetable

从多种传统腌制蔬菜中分离到12株乳酸菌,对它们的16S核糖体基因进行扩增测序,根据序列的同源性鉴定为植物乳杆菌(Lactobacillus plantarum)、沙克乳杆菌(Lactobacillus sakei)和戊糖片球菌(Pediococcus pentosaceus)。对其生化特征以及亚硝酸盐耐受性和降解能力进行了研究和比较,最终筛选出1株各项指标优良,且能快速降解亚硝酸盐的植物乳杆菌J-10,该菌降解亚硝酸钠的最适温度为37℃,最适pH值为6.2,在添加0.25 mg/mL的亚硝酸钠的培养液中培养24h后,亚硝酸盐降解率为99.2%。

Lactic acid bacteria are commonly used in food industry, mainly in the fermentation process of meat products, prickles and diary products. They can add special flavor and color to the products, depress the growth of pathogens, and reduce nitrite concentration in the products, which makes the products safer to the customers. 12 strains of lactic acid bacteria were isolated from the pickled vegetables. After amplification and sequencing of 16S rDNA gene, the isolated strains were identified by sequence homology as follows： 9 strains of Lactobacillus plantarum, 2 strains of Lactobacillus sakei and l strain of Pediococcus pentosaceus. Some of their biochemical characteristics were studied and compared, as well as their abilities on the tolerance and degradation of nitrite. A L. plantarum strain, named J-10, was approved to degrade nitrite quickly with good biochemical characteristics. When grown in 0.25 mg/ml nitrite sodium added medium, strain J-10 could degrade 99.2% nitrite sodium at 37℃ and pH 6.2 for 24 h.