Extraction of bacitracin from Bacillus subtilis BSG and its optimization using response surface methodology

Abstract

Bacillus sp. was isolated from the soil sample of Gunupur, Odisha, India and screened to produce bacitracin at the laboratory. The bacitracin from the bacterium was extracted using butanol-ether solution as a solvent and its antibacterial properties against five bacteria namely Staphylococcus aureus (MTCC 98), Escherichia coli (MTCC 739), Micrococcus luteus (MTCC 106), Salmonella typhimurium (MTCC 1254), and Pseudomonas aeruginosa (MTCC 2453) have been studied in vitro by agar well diffusion method. Simultaneously, the individual, square and combined effect of incubation time, pH and temperature on the bacitracin production was studied using Response Surface Methodology (RSP). Analysis of variance (ANOVA) has shown a coefficient of correlation value of 0.9611) and a quadratic correlation for bacitracin production was derived with 95% confidence level. Incubation time of 26.5 h; pH of 5.67; and temperature of 30.65 degrees C have been found to be as optimum operating conditions for a maximum bacitracin production from Bacillus sp. BSG of 8.72 mu g/100 ml.