Antimicrobial Activity and Peptidomic Analysis of Halotolerant Lactiplantibacillus plantarum CH

As antibiotic-resistant bacteria emerge, antimicrobial peptides have become a promising alternative due to their safety, low residue, and low resistance properties. This study evaluated the in vitro antibacterial activity of peptides obtained from the fermentation of a halotolerant Lactiplantibacillus plantarum CH. Moreover, an in silico antimicrobial activity of L. plantarum was predicted. The strain was previously isolated from ripened, salty Mexican cheese (Chiapas cheese) and genetically reidentified using 16S rRNA. Antimicrobial activity was assessed in MRS broth against five common food pathogens, and the proteinaceous nature of the active compounds was confirmed. Peptidomic analysis revealed 57 peptides with antimicrobial potential, ranging in molecular weight from 767.88 to 4859.55 Da. Three peptides (NINLQTELIAGVTSFFAISYIIVV, KDPFPFVHTNIIGTYT, and IKVIAGLVVIILAFLIGRILIQGV) demonstrated antimicrobial, antibacterial, antifungal, and antiviral activity. The peptide QSFQDTLPALVKGVILILIAWLVAVLVKNVVTKGFKKIKLD exhibited the highest antibacterial activity. Additionally, ten peptides contributed to the bacterium's probiotic effects, suggesting potential food preservation and health enhancement applications. The physicochemical properties of these peptides were explored to understand their mechanisms of action. However, further research involving synthesizing and testing the most active peptides is necessary to corroborate these findings and fully elucidate their potential as antimicrobial agents.