Cow Dung Substrate for the Potential Production of Alkaline Proteases by Pseudomonas putida Strain AT in Solid-State Fermentation

Cow dung and agroresidues were used as the substrates for the production of alkaline proteases by Pseudomonas putida strain AT in solid-state fermentation. Among the various substrates evaluated, cow dung supported maximum (1351±217 U/g) protease production. The optimum conditions for the production of alkaline proteases were a fermentation period of 48 h, 120% (v/w) moisture, pH 9, and the addition of 6% (v/w) inoculum, 1.5% (w/w) trehalose, and 2.0% (w/w) yeast extract to the cow dung substrate. The enzyme was active over a range of temperatures (50–70°C) and pHs (8–10), with maximum activity at 60°C and pH 9. These enzymes showed stability towards surfactants, detergents, and solvent and digested various natural proteins