Protease production by thermo-alkaliphilic novel gut isolate Kitasatospora cheerisanensis GAP 12.4 from Gryllotalpa africana

Abstract

In course of searching for proteolytic microbes from the gut of Gryllotalpa africana, a potent isolate GAP 12.4 was screened and identified as Kitasatospora cheerisanensis having protease activity 46.8 ± 1.52 U/ml. Optimum conditions for the protease production (605.3 ± 9.7 U/ml) were 7-d cultivation, 5% inoculum, pH 9.5, 55 °C, 150 rpm, and supplementation with 0.8% glucose and 0.6% ammonium sulfate. Surfactants such as SDS, EDTA, Tween 80 and Triton X-100 showed positive effect on enzyme production. Addition of biotin (50 μg/ml) promotes enzyme production maximally (674.15 ± 4.13 U/ml). Further enhancement on addition of casein hydrolysate and molasses to the production medium was 709.20 ± 7.53 U/ml and 744.26 ± 9.71 U/ml, respectively. The isolate was also able to utilize agro-industries waste, green gram husk in solid-state fermentation for enzyme production (1675.02 ± 21.58 U/ml). This thermo-alkaliphilic isolate may be a potent candidate for low cost protease production through management of agro-residues. It is the first report of protease production by a member of actinobacteria under the Kitasatospora genus.