Diversity of culturable actinobacteria producing protease inhibitors from the intertidal zones of Maharashtra, India

Phylogenetic diversity of culturable actinobacteria isolated from the intertidal regions of west coast of Maharashtra, India was studied using 16S rRNA gene sequencing. Total of 140 actinobacterial isolates were obtained, which belonged to 14 genera, 10 families and 65 putative species with Streptomyces being the most dominant genus followed by Nocardiopsis and Micromonospora. They were screened for production of extracellular protease inhibitors (PI) against three pure proteases viz. chymotrypsin, trypsin, subtilisin and one crude extracellular protease from Pseudomonas sp. 80% of the isolates showed protease inhibition activity against at least one of the proteases, majority of them belonged to genus Streptomyes. Actinobacterial diversity from two sites Ade and Harnai with varying degrees of anthropological pressures showed that more species diversity was obtained from site with minimal human disturbance i.e Ade, however, site with higher human disturbance, i.e. Harnai contained higher percentage of PI producing strains. Understanding association of PI production and abundance of extracellular proteases due to organic load in the marine environments can give interesting insights into the chemical ecology of microbial community in the intertidal region.