Genome and metabolites analysis reveal insights into control of foodborne pathogens in fresh-cut fruits by Lactobacillus pentosus MS031 isolated from Chinese Sichuan Paocai

The presence of pathogens in fresh-cut fruits represents a risk for the public health since these products generally do not receive any further treatment before consumption. In this study, a Lactobacillus pentosus MS031 was isolated from Sichuan Paocai with broad antibacterial activity against foodborne pathogens. Antimicrobial peptides produced by the L. pentosus MS031 had broad activity and resistance to heat, but they were sensitive to proteinases and their activity vanished under alkaline condition. Bacteriocin-like substance obtained by pH-absorption related methods showed activity only against Staphylococcus aureus. However, cell-absorbed substance and cell-secreted into culture substance had activity against both S. aureus and Escherichia coli. Foodborne pathogens in fresh-cut fruit mixture were controlled by the metabolites of the L. pentosus MS031 that Listeria monocytogenes was reduced by 96.3 %, Salmonella typhi and E. coli were decreased to an undetectable level. The complete genome of the L. pentosus MS031 was sequenced using Illumina and MinION nanopore platform with a size of 3,805,216 bp, consisting of one chromosome and eight plasmids. After mining using BAGEL4, two novel bacteriocins, pentocin MS1 and pentocin MS2, were identified. Furthermore, fragments of 5 antimicrobial peptides were identified by LC-MS/MS in the fermentation supernatant. In addition, antimicrobial cyclic dipeptides and small compounds were identified in the antimicrobial metabolites. The results indicate antimicrobial metabolites of the L. pentosus MS031 can control foodborne pathogens in fresh-cut product during subsequent cold storage, which is significant for food industry.