Novel Regulatory Interplay between FtsH and Spo0A∼P in <i>Bacillus cereus</i> 0–9 Biofilm Formation: A Potential Target for Antibiofilm Strategies

The biofilm formation of <i>Bacillus cereus</i> brings new challenges to food hygiene control. We investigated the multifunctional role of FtsH, an ATP-dependent metalloprotease, in regulating biofilm formation and environmental adaptation in <i>B. cereus</i> 0-9. Through homologous recombination, we generated Δ<i>ftsH</i> and related mutants, subsequently evaluating their biofilm production using crystal violet staining, colonial morphology, and sporulation capacity, respectively. Transcriptional analysis using luminescent reporter strains revealed that biofilm-associated genes (<i>sipW</i> and <i>calY</i>) are downregulated in a FtsH-dependent manner in the mutants. Our findings demonstrate FtsH modulates Spo0E protein stability (confirmed by Western blot) and consequently influences Spo0A phosphorylation levels. Thus, FtsH as a crucial regulator of both sporulation and biofilm formation in <i>B. cereus</i> 0-9, mirroring its function in <i>Bacillus subtilis</i> while differing from <i>Bacillus anthracis</i>. It provides novel insights into bacterial stress response mechanisms and offers potential applications for developing biofilm eradication strategies, thereby addressing critical disinfection challenges in food processing environments.