Purification and Characterization of a New Bacillus thuringiensis Bacteriocin Active Against Listeria monocytogenes, Bacillus cereus and Agrobacterium tumefaciens

Abstract

This study reports on the identification, characterization and purification of a new bacteriocin, named Bacthuricin F103, from a Bacillus thuringiensis strain BUPM103. Bacthuricin F103 production began in the early exponential phase and reached a maximum in the middle of the same phase. Two chromatographic methods based on high performance liquid chromatography and fast protein liquid chromatography systems were used to purify Bacthuricin F103. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that this bacteriocin had a molecular weight of approximately 11 kDa. It also showed a wide range of thermostability of up to 80 °C for 60 min and a broad spectrum of antimicrobial activity over a pH range of 3.0-10.0. This bacteriocin was noted, and for the first time, to exhibit potent antimicrobial activity against Agrobacterium subsp. strains, the major causal agents of crown gall disease in tomato and vineyard crops, and against several challenging organisms in food, such as Listeria monocytogenes and Bacillus cereus. Complete killing with immediate impact on cells was observed within a short period of time. The sequence obtained for Bacthuricin F103 by direct N-terminal sequencing shared considerable homology with hemolysin. Bacthuricin F103 was noted to act through the depletion of intracellular ions, which suggest that the cell membrane was a possible target to Bacthuricin F103.

Purification and Characterization of a Novel Cold Shock Protein-Like Bacteriocin Synthesized by Bacillus thuringiensis

“…Bacillus thuringiensis (Bt) is one of the most successful entomopathogenic bacteria that has been used as a biopesticide due to its ability to synthesize insecticidal crystal proteins (ICPs) during sporulation and vegetative insecticidal proteins (VIPs) during the vegetative phase of growth 5 7 8 9 . Bt can also produce a variety of bacteriocins, called thuricins, with known sequences and bacteriocin-like inhibitory substances (BLIS), but these substances have not yet been fully characterized 10 11 12 13 . Thus, Bt bacteriocins may expand the potential of this insecticide to other purposes 5 .…”

Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications

“…Importantly, it is highly active against B. cereus, which is one of the most virulent bacteria that may be found in agro-industrial products [ 22 ]. Although this bacteriocin is less active against Gram-negative bacteria [ 35 ]. It is the only bacteriocin produced by B. thuringiensis , which displays activity against K. pneumoniae.…”

Future Challenges and Prospects of Bacillus thuringiensis

“…Bacteriocins can also be used to control pest that affect honeybees, for example, Entomocin 110 has growth inhibitory activity to Paenibacillus larvae, the causal agent of American foul-brood of honeybees ( A. mellifera L.) (Cherif et al 2008). Finally, bacteriocins of B. thuringiensis have growth inhibitory activity against the phytopathogenic bacteria, for example Bacthuricin F103 synthesized by B. thuringiensis strain BUPM103 showed inhibitory effect to Agrobacterium tumefaciens (Kamoun et al 2011).…”