Production and purification of a hyperthermostable chitinase from Brevibacillus formosus BISR-1 isolated from the Great Indian Desert soils.

A strain of Brevibacillus formosus, capable of producing a high level of chitinase, was isolated and characterized for the first time from the Great Indian Desert soils. The production of extracellularly secreted chitinase was analyzed for its biocontrol potential and optimized by varying media pH, temperature, incubation period, substrate concentrations, carbon and nitrogen sources, etc. A twofold increase in chitinase production (798 IU/mL) was achieved in optimized media containing (g l(-1)) chitin 2.0, malt extract 1.5, glycerol 1.0, ammonium nitrate 0.3%, T-20 (0.1%) and media pH 7.0 at 37 °C. The produced enzyme was purified using a three-step purification procedure involving ultra-filtration, ammonium sulphate precipitation and adsorption chromatography. The estimated molecular weight of the purified enzyme was 37.6 kDa. The enzyme was found thermostable at higher temperatures and showed a t ½ of more than 5 h at 100 °C. Our results show that the chitinase produced by B. formosus BISR-1 is thermostable at higher temperatures.