Abstract:

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.

Key words: nitrite degradation, lactic acid bacteria, domestication, antibacterial, identification