Uncovering the potential of rosmarinic acid as a natural antimicrobial agent: effective inhibition of growth and biofilm formation in Bacillus cereus

Bacillus cereus is a foodborne pathogen capable of producing various toxins that cause food poisoning. Both B. cereus and its biofilm pose significant threats to the development of the food industry and human health. Therefore, identifying effective strategies to inhibit B. cereus is crucial. This study investigated the antibacterial mechanism of rosmarinic acid (RA) and its potential application in wheat bread dough. The results indicated that RA inhibits the growth of B. cereus by inducing membrane depolarization, increasing intracellular reactive oxygen species (ROS), and reducing intracellular DNA, ATP, and protein content. These alterations result in membrane damage and ultimately lead to cell death. Furthermore, RA decreased the structural integrity and functionality of the biofilm and inhibited the production of virulence factors such as flagella, hemolysin, protease, and phospholipase. Transcriptomic and metabolomic analyses further revealed that RA causes osmoregulatory imbalance, disrupts energy metabolism, and impairs nucleic acid metabolism in B. cereus. It also suppressed toxin and flagellum expression, disrupted bacterial intercommunication, and ultimately triggered bacterial inactivation and death. Additionally, RA significantly inhibited the growth of B. cereus in wheat bread dough without affecting yeast activity, highlighting its potential as a natural antimicrobial agent and offering a new solution for food safety.