ABSTRACT

The antimicrobial activity of some bacteriocin strains produced by Bacillus thuringiensis (Bt) bacteria had been tested against Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa bacteria under different concentrations of ammonium sulfate. The Bt strains were previously isolated from various habitats in Middle Tennessee (USA). Bacteriocin production and activity were defined by the agar well diffusing using the sensitivity of the standard reference bacteria as a measure of its activity. No inhibition was observed on P. aeruginosa upon incubation with many bacteriocins in 20% ammonium sulfate precipitate, while a medium inhibition zone was observed for other bacteriocins under these same conditions. A strong inhibition zone was shown for some strains against S. aureus with 20%, 30% and 40% of ammonium sulfate, while no inhibition zone observed for bacteriocin produced by other strains with 20% ammonium sulfate precipitate against B. cereus. Increasing concentrations of ammonium sulfate adequately increase the antimicrobial activity of bacteriocins. Keywords: Bacillus thuringiensis (Bt); Bacteriocins, Antibacterial, Ammonium sulfate
Publication date: 01/09/2021

https://ijbpas.com/pdf/2021/September/MS_IJBPAS_2021_5618.pdf

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https://doi.org/10.31032/IJBPAS/2021/10.9.5618