Lacticaseibacillus zeae PW3 combats multiple foodborne pathogens: Antibacterial activity and metabolomics analysis

This study aimed to investigate the antibacterial and antibiofilm effects of Lacticaseibacillus zeae ( L. zeae ) against foodborne pathogens, as well as the antibacterial substances in its cell-free supernatant (CFS). L. zeae PW3, isolated from fermented bran, exhibited notable antibacterial activity against both Gram-positive and Gram-negative pathogens. Furthermore, it considerably reduced the cell viability of Staphylococcus aureus (strain number: ATCC 6538), Salmonella enterica serovar Enteriditis (strain number: CMCC(B) 50335), and Streptococcus agalactiae (strain number: CMCC(B) 32116) and inhibited their biofilm formation. Scanning electron microscopy revealed morphological deformations in pathogenic cells induced by PW3 CFS that culminated in cytoplasmic content leakage and bacterial mortality. Notably, L. zeae PW3 CFS exhibited remarkable thermostability and pH tolerance. Moreover, metabolomics analysis revealed that the components of PW3 CFS mainly consisted of organic acids (27.78 %) and lipids (22.22 %). Together, these findings provide insights that will facilitate the development of alternative biopreservatives for controlling foodborne pathogens in the food industry. • L. zeae PW3 was isolated from fermented bran. • PW3 showed broad antimicrobial activity against both Gram+ and Gram-foodborne pathogens. • Pathogenic biofilm formation was inhibited upon PW3 treatment. • PW3 CFS exhibited remarkable thermostability and pH tolerance. • The antibacterial substances in PW3 CFS were identified using metabolomics analysis.