Quantitative proteomics reveals energy metabolism remodeling in Bacillus cereus spores under pulsed light treatment

Pulsed light (PL) is an emerging non-thermal sterilization technology. However, its molecular inactivation mechanisms against the highly resistant dormant spores of the foodborne pathogen Bacillus cereus remain poorly understood, representing a critical research gap. To address this, our specific contribution involved employing a data-independent acquisition (DIA)-based quantitative proteomic approach to elucidate the dynamic protein-level responses of B. cereus spores to PL treatment. A total of 489 proteins exhibiting differential abundance (270 demonstrating increased abundance, 219 demonstrating decreased abundance) were identified. Bioinformatics analyses indicated significant enrichment in RNA polymerase, RNA degradation, and ribosomal biosynthesis pathways. Furthermore, proteins constituting key energy production pathways, including the phosphotransferase system (PTS), pyruvate metabolism, and fatty acid synthesis, exhibited significantly increased abundance, indicating a potential disruption leading to the accumulation of pyruvate and long-chain fatty acids. Conversely, the decreased abundance of terminal proteins in the oxidative phosphorylation pathway, such as bacterial cytochrome c oxidases and ATP synthase subunits, points to a potential physical impairment in ATP synthesis machinery and a structural contribution to reactive oxygen species accumulation. Structural analysis revealed altered abundance of proteins associated with the exosporium, spore coat, cortex, germination receptors, and small acid-soluble proteins (SASPs), suggesting that PL exposure may affect molecular components related to spore structural maintenance, germination readiness, and DNA protection. Practically, these proteomic findings provide data-driven molecular clues to PL-induced spore inactivation and offer a mechanistic basis for further evaluating PL-based non-thermal strategies aimed at reducing B. cereus spore-related risks in food safety applications.