Novel sequence types of Lactococcus lactis subsp. lactis obtained from Brazilian dairy production environments

Lactococcus lactis subsp. lactis strains are widely used by the dairy industry in fermentation processes. This study aimed to characterize the genetic diversity of L. lactis subsp. lactis isolated from Brazilian dairy environments. A collection of 23 isolates of L. lactis subsp. lactis was subjected to rep-PCR (GTG(5)) and PFGE (Smal) to determine their genetic profiles. rep-PCR allowed a maximum similarity of 97.2% among strains, while PFGE grouped isolates in four clusters, and it was possible to identify isolates with 100% of similarity. The selected strains were also subjected to MLST (pepXP, pgk, glyA, recN, bcaT and pdp), resulting in the characterization of 11 STs; nine of them were firstly described in the present study. ST grouping allowed for the characterization of 2 CC: CC1 with 3 isolates and CC2 with 2 isolates. The remaining STs were distributed as singletons. These results show that L. lactis subsp. lactis obtained from Brazilian dairy environments present a high genetic diversity, highlighting the relevance of further studies to characterize their beneficial potential to be exploited by the food industry.