Optimization of Extracellular Alkaline Protease Production From Pseudomonas aeruginosa Isolated from Soil Samples

Proteolytic enzymes are ubiquitous in nature present in all forms of life from viruses to animals. Among them microbial proteases secure most significant position due to their vast industrial applications. In this study 148 bacterial strains were isolated from 50 different soil samples of slaughter house, fish market and sewage wastes of Lucknow, Uttar Pradesh, India. Out of which fifty six strains competent of secreting extracellular alkaline protease. In preliminary screening the isolate SSB1 showed highest ability to hydrolyzed casein and skimmed milk which was done on skim milk agar media. The isolates showed positive for casein, gelatin, oxidase, starch, and catalase test and negative for gram staining, indole, methyl red, voges proskauer, urea, hemolysis and triple sugar iron (TSI) test and found to be motile. The culture conditions were optimized for utmost enzyme production. Many physical parameters were deliberated to optimize the maximum yield of alkaline protease. The optimum conditions for the maximum protease production were when cultivated for 36 h at 37°C in a medium containing 1% glucose, 1% yeast extract, 1M NaCl, and 1mM Zn²⁺ at pH 9.0. Strain SSB1 with the maximum yield alkaline protease was identified as Pseudomonas aeruginosa based on nucleotide homology and phylogenetic analysis. The study revealed that the bacterial strain of P. aeruginosa is a potent source of extracellular alkaline protease and optimization of culture conditions for the maximum yield and their applications in different industries.

SSB1 strain identified as Pseudomonas aeruginosa, a protease producing bacterium from soils, a potential producer of protease which could find applications in industry & biotechnology.