Whole-genome sequence analysis and probiotic characteristics of Lactococcus lactis Subsp. lactis strain Lac3 isolated from traditional fermented buffalo milk (Dadih)

Abstract

Background: Probiotics are live microorganisms that provide beneficial effects on the host’s health when exploited in adequate amounts. This study aimed at carrying out whole-genome sequence analysis and in vitro potential probiotic characteristics of Lactococcus lactis subsp. lactis strain Lac3 isolated from the spontaneously fermented buffalo milk named Dadih. Results: The results from de novo assembly indicated that the assembled genome consisted of 55 contigs with a genome size of 2,441,808 bp ~ (2.44 Mb), and GC % content of 34.85%. The evolution history result showed that the strain Lac3 was closely related to Lactococcus lactis species deposited in NCBI with a sequence similarity ≥ 99.93%. L. lactis subsp. lactis Lac3 was non-pathogenic with a probability of 0.21 out of 1 and had a pathogenicity score of zero (0), and neither harbored virulence factors nor acquired antibiotic resistance phenotypes. L. lactis subsp. lactis Lac3 exhibited the potential probiotic characteristics to tolerate acid at pH (2.0 and 5.0), salinity (1–5% NaCl), bile salt of (0.3–1.0%) and had auto-aggregation capacity increased from 6.0 to 13.1%. Conclusion: This study described a novel strain of Lactococcus lactis subsp. lactis called Lac3, which exhibits probiotic properties that could be beneficial in the development of probiotics.