Evaluation of Probiotic Strains Isolated from Artemisia argyi Fermentation Liquor and the Antagonistic Effect of Lactiplantibacillus plantarum against Pathogens

This study was aimed at screening potential probiotic candidates to enhance the antimicrobial activity of Artemisia argyi against foodborne pathogens. Ten LAB strains were isolated from natural Artemisia argyi fermentation liquor (AAFL) and assessed for safety and antimicrobial ability. Therein, Lactiplantibacillus plantarum WLPL01, Lacticaseibacillus casei WLCA01, WLCA02, and WLCA03, and Lactobacillus harbiness WLHA01 were further evaluated for their potential probiotic properties (gastrointestinal tolerance and adhesion capacity). The results suggested that L. plantarum WLPL01 exhibited excellent properties and was, therefore, selected as the starter for A. argyi leaves fermentation. Then, L. plantarum WLPL01-fermented AAFL (AAFL-LP) was further investigated for its antimicrobial activity against foodborne pathogens. The results demonstrated that the inhibitory effect of AAFL-LP to foodborne pathogens, such as Listeria monocytogenes CMCC54007, Salmonella Typhimurium ATCC 13311, and Candida albicans ATCC 14053, was enhanced when compared to spontaneously fermented AAFL (AAFL-spontaneous). In addition, an analysis of the whole genome of L. plantarum WLPL01 revealed the presence of 13.9 kb long and 16 plantaricin-encoding loci (pln locus), and the increased antimicrobial activities of AAFL-LP might correlate with the production of bacteriocin. Our results indicate that L. plantarum WLPL01 can be used as a starter for Artemisia argyi fermentation to enhance its antimicrobial activity against foodborne pathogens.