Construction of mixed fermentation bacteria community of lactic acid bacteria from fermented pepper

Abstract

Superior acid-producing, amino acid nitrogen producing, nitrite-reducing and aromatic lactic acid bacteria were isolated and screened from traditional fermented vegetables, and the mixed fermentation bacteria community was constructed by 16S rDNA sequence analysis, antagonism and symbiosis study. Its antibacterial ability was studied, and verified by pepper fermentation tests. The results showed that superior acid-producing lactic acid bacteria H3D and 6d-6 were screened, and the acid yields were 5.40 g/L and 4.50 g/L, respectively, in MRS medium supplemented with 10% salt. Superior amino acid nitrogen-producing lactic acid bacteria T216 and 3-2 amino acid nitrogen yields were 0.22 g/100 ml and 0.18 g/100 ml, respectively; The nitrite degradation rates of superior nitrite-reducing lactic acid bacteria 63 and T244 were more than 67%; The acetoin yield of superior aromatic lactic acid bacteria 206 and 6-12, were 24.30 mg/L and 23.32 mg/L, respectively. Strains 63, H3D, 6d-16 and 3-2 were identified as Lactiplantibacillus plantarum, strains 206 and 6-12 were identified as Pediococcus pentosaceus, strains T244 were identified as Weissella cibaria, and strains T216 were identified as Lactobacillus brevis, and these strains were not antagonistic when cultured in pairs. Strains H3D, 206, T216 and T244 were selected for mixed culture. The four strains could symbiosis in mixed culture and had a good inhibitory effect on foodborne pathogens. When the inoculation ratio of mixed bacteria was 1∶1∶1∶1, the fermented pepper was of the best quality. Compared with natural fermented pepper, the contents of total acid, amino acid nitrogen and acetoin increased by 36.11%, 33.33% and 107.12%, respectively, and the content of nitrite decreased by 84.49%.

Keywords

• fermented pepper|lactic acid bacteria|screening|identification|mixed bacteria community|symbiotic characteristics