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Partial characterization of bacteriocin‐like compounds from two strains of Bacillus cereus with biological activity against Paenibacillus larvae, the causal agent of American Foulbrood disease
Author(s) -
Minnaard J.,
Alippi A.M.
Publication year - 2016
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12665
Subject(s) - american foulbrood , bacillus cereus , bacteriocin , cereus , biology , microbiology and biotechnology , bacteria , paenibacillus , antibacterial activity , paenibacillus polymyxa , 16s ribosomal rna , spore , antimicrobial , genetics
American Foulbrood (AFB), caused by the spore‐forming Gram‐positive bacterium Paenibacillus larvae, is the most severe bacterial disease affecting honeybees worldwide. Two bacterial isolates showing specific inhibitory activity against P . larvae were identified as Bacillus cereus by 16S rDNA sequencing. Antagonistic compounds were obtained from cell‐free supernatants of strains m6c and m387 growing on Trypticase Soy Broth and concentrated by NH 4 SO 4 precipitation, ultrafiltration and butanol extraction. Both compounds were characterized as bacteriocin‐like inhibitory substances ( BLIS ). BLIS m6c and BLIS m387 were stable at 70°C for 30 min and active in the pH range from 3 to 7. The antibacterial activity was completely lost at pH values higher than 8 or temperatures >80°C. Both BLIS have a narrow activity range and highly inhibit the growth of P. larvae . BLIS m6c and BLIS m387 differ from each other and other BLIS reportedly produced by B. cereus with regard to their molecular weights, antibacterial activity, minimal inhibitory concentration values and sensitivity to degradative enzymes. The findings of this study suggest that BLIS m6c and BLIS m387 can potentially be used to control AFB. Significant and Impact of the Study An Integrated Pest Management ( IPM ) approach is needed to ensure the sustainability of the beekeeping industry due to the increasing demand for organic honey and the reduction of dependence on antibiotics. Biocontrol agents produced by bacteria isolated from apiarian sources seem promising and able to combine with an IPM strategy. The most significant findings of this study are the characterization of bacteriocin‐like compounds ( BLIS ) obtained from two strains of Bacillus cereus isolated from honey. Both BLIS have a narrow activity range and highly inhibit the growth of Paenibacillus larvae, the causal agent of American Foulbrood disease of honey bees.