Isolation and screening of thermophillic bacteria and its subsequent evaluation for lipases production

Abstract

Thermophilic bacteria are always being attracted for their thermostable products including enzymes. In the present work, isolation and screening of thermophilic lipolytic bacterial strains were performed from hot spring environments of Azad Jammu, Kashmir, and Manghopir, Karachi. Forty-eight bacterial strains were isolated using serial dilution method. Phenol red agar medium was used to screen hyper producers for lipases production through agar well diffusion technique. Fifteen strains were found lipolytic positive. Six were selected as lipases hyper producers based on zone hydrolysis. Their compatibility was checked with all other strains for the formulation of bacterial consortium for maximum lipolytic activity. By fermentation process, the highest lipases production was observed by consortium of Bacillus toyonensis (L2AKh) and Bacillus thuringiensis (L2AKo), which was selected for subsequent lipases synthesis. Various physiological variables, including pH, incubation temperature and incubation time, were optimized for maximum lipases synthesis. Lipases produced by thermophilic bacteria had optimum pH of 6, incubation temperature of 60 o C, and an optimum incubation period was found to be 24h. The thermostable lipases produced in the present study are suitable for exothermic reactions on an industrial scale.