Isolation and identification of bacteriocin-producing lactic acid bacteria from Daqu and mining of bacteriocin gene

Bacteriocins are peptides or proteins produced by ribosomes that have bacteriostatic activity. Lactic acid bacteria (LAB) are the main producers of bacteriocins, and most studies have screened bacteriocin-producing lactic acid bacteria from traditional dairy products, screening lactic acid bacteria from new materials has become an important aim of bacteriocin exploration at this stage. A total of 49 LAB strains of 20 species in 6 genus were screened from a mixed sample of eight Daqu using traditional pure culture methods. And the results were then combined with high-throughput sequencing to further understand the distribution of LAB in Daqu. At the same time, the diversity of model LAB bacteriocins was explored through database analyses. Using BAGEL4 software and computer mining method, 286 gene clusters of 183 homologs from 60 different types of bacteriocins were predicted and a phylogenetic tree has been constructed to better show the distribution characteristics of bacteriocin related genes in LAB species. This study also shows that Daqu has the potential to mine bacteriocin-producing lactic acid bacteria, and provides a reference for enriching the sources of new bacteriocins.