Abstract

Pseudomonas aeruginosa JM07 which produces an extracellular alkaline protease was isolated from the Yellow Sea in China. The cultural conditions were optimized for maximum enzyme production. Maximum enzyme activity was achieved when the bacterium was grown in soybean meal (3.5%, w/v), corn steep meal (1.5%, w/v), Na₂HPO₄ (0.4%, w/v), KH₂PO₄ (0.03%, w/v), Na₂CO₃ (0.02%, w/v), MgSO₄ (0.02%, w/v), CaCl₂ (0.2, w/v), at pH 7.0 and 20°C over 12 h incubation period. The enzyme hadan optimum pH of around 10 and maintained its stability over a broad pH range between 7 and 12. Its optimum temperature is around 30°C, and exhibited a stability of up to 40°C. The enzyme activity was strongly inhibited by DFP, suggesting that it belongs to the family of serine proteases.

Key words: Pseudomonas aeruginosa, alkaline protease, by-product.