Screening, identification and characteristics of acid-tolerant lactic acid bacteria in low-salt pickles

Abstract

Objective: This study focused on screening lactic acid bacteria strains with potential probiotic properties. Methods: Five strains of acid-tolerant lactic acid bacteria were screened from twelve low-salt pickles with salt content ≤6%, identified by 16S rDNA, and their probiotic properties were studied. Results: The five strains were Leuconostoc mesenteroides J2, Lactobacillus paracasei N6, Lactobacillu paraplantarum F8, Weissella cibaria M1 and Weissella cibaria M12. Among them, the relative growth rates of L. paracasei N6, W. cibaria M1 and W. cibaria M12 in pH 4.0 medium were 84.23%, 78.32% and 76.29%, respectively, which had strong acid-tolerant capacity. After digestion with gastric fluid at pH 3.0 and intestinal fluid at pH 8.0, the survival rates were 79.26%, 50.65% and 53.37%, respectively, which had strong tolerance to both artificial gastric fluid and intestinal fluid environments. After cultured in 0.3% bile salt for 8 h, the survival rates were more than 30%, and they had strong bile salt tolerance. The hydrophobic rates and self-aggregation rates were both above 60%, and they had strong hydrophobic and self-aggregating capacity. Conclusion: In this study, three strains of acid-tolerant lactic acid bacteria L. paracasei N6, W. cibaria M1 and W. cibaria M12 with probiotic properties were screened, which could be used in the study of compound probiotics.

Keywords

• low-salt pickles
• acid tolerance
• lactic acid bacteria
• 16s rdna
• in-vitro probiotic properties