Antibacterial Activity of Native Bacillus thuringiensis Strains from Fernandez Canyon State Park, Mexico

Abstract

Bacillus thuringiensis is a microbial insecticide whose presence in the Fernandez Canyon State Park, a protected natural area in the north of Mexico, has not been reported. The objective of this work was to isolate Bacillus thuringiensis strains isolated from the Fernandez Canyon State Park with the capacity to synthesize antimicrobial peptides (bacteriocins). We showed the isolation and characterization of two native strains of Bacillus thuringiensis (CF13 and CF42) collected from soils of the protected area. Bacteria were identified based on its capacity to synthesize spherical crystals and by sequencing of the flagellin gene. Both strains produced bacteriocins with bactericial/bacteriolytic activity against Bacillus cereus, with molecular mass of 10 kDa and 15 kDa, susceptible to proteolytic treatment, thermotolerants and with activity to ten Gram-positive and eight Gram-negative bacteria that might affect human and animal health. The importance of this work is that it is reported for the first time the isolation and characterization of bacteriocinogenic strains of Bacillus thuringiensis native from the Fernandez Canyon State Park, a protected natural area in Mexico.