The probiotic Lactiplantibacillus plantarum ATCC10241 inhibits wound-associated pathogens through the secretion of organic acids.

While probiotics are traditionally studied for their role in gut health, they are also being explored for their potential to treat wound infections and enhance wound healing. One probiotic strain commonly studied in the context of wound care is Lactiplantibacillus plantarum ATCC10241. Although its antimicrobial activity against Pseudomonas aeruginosa has been well-established, data on the activity against other wound-associated pathogens is more limited. Here, we demonstrate that this probiotic also inhibits the growth of other clinically relevant pathogens such as Acinetobacter baumannii and, to a lesser extent, Staphylococcus aureus. While we identify a putative bacteriocin cluster encoding the well-characterized plantaricins PlnJK and PlnEF, these antimicrobial peptides did not substantially contribute to antimicrobial activity, even though they were weakly expressed in our in vitro setups. Instead, antimicrobial activity was completely lost when the pH was neutralized, and lactic acid alone was sufficient to mimic the antimicrobial activity of L. plantarum ATCC10241. Consistent with previous work, these result confirm that acidification of the environment through the accumulation of organic acids is more important than plantaricins to explain the antimicrobial potential of L. plantarum ATCC10241.