Production of alkaline protease by Bacillus circulans using agricultural residues: A statistical approach

Abstract

Bacillus circulans, an alkaline protease producer isolated from vegetable waste, showed a pH of 10.5, temperature between 25-30°C and agitation rate of 200 rpm as optimum physical conditions for enzyme production. Factorial experiments were designed and the best CN combination of glucose and soybean meal produced a maximum alkaline protease of 461.65 U/mL. Soybean meal replaced with cotton deoiled meal (CDM) from enzyme production medium as the maximum supporter of alkaline protease produced 589 U/mL of protease. Protease values with different concentrations of CDM fitted in a regression equation showed that B. circulans produces maximum alkaline protease of 808.68 U mL⁻¹ in 100.9 h using 0.5789% CDM.