高效降亚硝酸盐乳酸菌的驯化复筛及菌株鉴定

目的：筛选出高效降亚硝酸盐乳酸菌，为今后益生乳酸菌的开发提供一定的理论依据。方法：从地方特有食品及动物肠道中分离纯化出13 株乳酸菌，采用盐酸萘乙二胺法对13 株乳酸菌的体外降亚硝酸盐能力进行测定，并对降亚硝酸盐效果最强菌株进行驯化培养和抑菌实验，通过生理生化及16S rDNA法对所分离的降亚硝酸盐能力最强菌株进行鉴定。结果：获得1 株编号为JS3的乳酸菌，该菌对亚硝酸盐降解率为83.39%，经过驯化复筛及培养条件优化得到：培养基中蛋白胨添加量15 g/L、接菌量5%、培养温度30 ℃、培养时间48 h，其降解率达到93.47%，同时菌株对金黄色葡萄球菌和枯草芽孢杆菌还具有抑制性能。经鉴定菌株为玉米乳杆菌（Lactobacillus zeae），将其命名为L. zeaeJS3。结论：菌株JS3具有高效降解亚硝酸盐能力，能够成为今后降解亚硝酸盐微生态活性菌的优良菌种。

Screening and Identification of Nitrite-Degrading Lactic Acid Bacteria

Objective: To screen nitrite-degrading lactic acid bacteria (LAB), and thus to lay a theoretical foundation for
the future development of probiotic lactic acid bacteria. Methods: Totally 13 LAB strains were isolated and purified from
unique local foods and animal intestines, and their nitrite-degrading abilities were evaluated by the naphthyl ethylenediamine
dihydrochloride spectrophotometric method. Biochemical assays and 16S rDNA sequencing were used to identify the lactic
acid bacteria with the highest nitrite-degrading capacity. Results: A nitrite-degrading strain, JS3, was obtained, which was
found to be able to degrade 83.39% nitrite. The optimized culture conditions for enhanced nitrite degradation by the selected
strain were determined as peptone concentration in medium of 15 g/L, inoculum quantity of 5%, and culture at 30 ℃ for
48 h, resulting in a degradation rate as high as 93.47%. The strain had obvious antibacterial activity against Staphylococcus
aureus and Bacillus subtilis. It was identified as Lactobacillus zeae and named L. zeae. JS3. Conclusion: The strain JS3 has
efficient nitrite-degrading capacity, and it is potentially an excellent species for the degradation of nitrite in the future.