Strain Improvement of Halotolerant Actinomycete for Protease Production by Sequential Mutagenesis

Proteases are the natural biocatalysts that due to their enormous range and specificity have attracted the attention of the scientists globally for better microbial sources for enhanced production of the enzyme. However, bacterial proteases from Bacillus are comprehensively studied and characterized, less attention has been paid to proteases produced by Actinomycetes. In the present investigation, a protease producing halotolerant and alkaliphilic Actinomycete, A1F2, was isolated from water of Sambhar Salt Lake, Rajasthan, India identified as Streptomyces sp. To further enhance the production, the isolate was subjected to sequential random mutagenesis using acridine orange, ethidium bromide and Ultraviolet radiation. The protease production in shake flask increased approximately 2.2-fold from parent to the final mutant. The results suggest that the process of sequential random mutagenesis is more efficient in strain improvement than a single mutagen treatment. The hyper active protease producing mutant can be used for industrial applications.