Isolation and classical identification of potent extracellular alkaline protease producing alkalophilic Bacillus sp from coastal regions of Tamil Nadu

Microbial proteases are vastly demanded industrial enzyme with broad commercial application in various sectors. Naturally, the bacterial strains are well known for their ability to excrete enzymes into the environment. The current work was undertaken to isolate and characterize an effective extracellular alkaline protease producing Bacillus sp. A total of twenty nine bacterial strains were isolated from coastal regions of rhizosphere soil around the Cuddalore District Tamil Nadu, India. Out of twenty nine isolates, seven strains namely, IAS01, IAS02, IAS03, IAS04, IAS05, IAS06 and IAS07 show 45% clearance of hydrolyzing zone on skim milk agar plate. The positive isolates were further assay on small scale laboratory fermentation media for their protease productivity when compared with standard culture, Bacillus subtilis (MTCC-1789). As a result, the highest enzyme productivity that appeared in the strain IAS01 was found to be 332.13±1.31 U/ml at alkaline condition. Therefore, the selected isolate IAS01 was a promising strain for alkaline protease producer and identified as B. subtilis based on its morphological, physiological, biochemical characters and analysis of the 16S rRNA gene sequencing study. The partial 16S rRNA sequence was submitted to Genbank, with the accession number KF761633.