Screening and optimization of protease production from a halotolerant Bacillus licheniformis isolated from saltern sediments

Protease producing halotolerant bacterium was isolated from saltern pond sediment (Tuticorin) and identified as Bacillus licheniformis (TD4) by 16S rRNA gene sequencing. Protease production was enhanced by optimizing the culture conditions. The nutritional factors such as carbon and nitrogen sources, NaCl and also physical parameters like incubation time, pH, agitation, inoculum size were optimized for the maximum yield of protease. Studies on the effect of different carbon and nitrogen sources revealed that xylose and urea enhances the enzyme production. Thus, with selected C–N sources along with 1 M NaCl the maximum protease production (141.46 U/mg) was obtained in the period of 24 h incubation at pH 8 under 250 rpm compared to the initial enzyme production (89.87 U/mg).