Plant-Based fermented foods harbor autochthonous lactic acid bacteria with broad antimicrobial activity, bacteriocin diversity, and probiotic potential

Abstract

Plant-based fermented foods are increasingly recognized as an underexplored niche for autochthonous and beneficial lactic acid bacteria (LAB) with multiple biotechnological and functional potential in health and agrifood systems. We isolated LAB from plant-based fermented foods and assessed their antimicrobial, functional, and probiotic potential using agar-well diffusion technique, in vitro colonization resistance and gastric-environment survivability assays, and 16S rRNA sequencing. Thirteen autochthonous LAB identified as Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus, Weissella confusa, Weissella paramesenteroides, and Weissella cibaria demonstrated inhibitory activity against ≥ 3 pathogens, including Methicillin-Resistant Staphylococcus aureus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, Enterococcus faecium, Enterococcus faecalis, and Pasteurella multocida. The selected LAB strains harbor at least 1 bacteriocin gene, including Plantaricin EF, Plantaricin K, Plantaricin J, Nisin, and Pediocin, and also competitively excluded most pathogens in co-culture experiments, with viable counts ranging from 3.0 to 6.0 log CFUmL−1. Interestingly, the LAB strains showed varying degrees of survivability to simulated gastric conditions, as well as auto- and coaggregation, hydrophobicity, hydroxyl scavenging, and exopolysaccharide production, and were universally non-hemolytic. Our study demonstrates plant-based fermented foods as notable sources of beneficial LAB with multifunctional biotechnological potential for application in health and agrifood systems.