Bacillus cereus 0-9 is a biocontrol strain with abundant antimicrobial peptide (AMP) biosynthesis gene clusters. This strain exhibits significant antibacterial activity against Gram-positive bacteria. Notably, the deletion of gene abrB, encoding global transcriptional regulator AbrB, resulted in a 62. 74% increase in the antibacterial efficacy of strain 0-9. EMSA studies revealed that the gene cluster lanT, responsible for producing key components of antibacterial activity, is dual-regulated by AbrB. In the ΔabrB strain, five novel AMPs were identified, with MICs ranging from 125 to 250 μg/mL against Corynebacterium glutamicum, surpassing the antibacterial efficacy of Nisin Z. Furthermore, the presence of K+, Ni2+, Zn2+, and Ca2+ ions significantly enhances the antibacterial activity of the peptides TPV21, LLV7, and CPR6. The genes FRY47₀3100 and FRY47₁5105, which encode precursor proteins associated with LLV7 and CPR6, are also directly regulated by AbrB. This research expands our understanding of Bacillus-derived AMPs regulated by AbrB in B. cereus 0-9.
Wang et al. (Wed,) studied this question.