[Production of neutral beta-mannanase by Bacillus subtilis and its properties]

Neutral beta-mannanase was produced by Bacillus subtilis BM9602 isolated from a soil. For this strain the neutral beta-mannanase was produced only when polysaccharides were used as a carbon source. Organic nitrogen source was superior to inorganic nitrogen source on the enzyme production. The optimum liquid medium consisted of 4% konjak powder, 1% each of beef peptone and yeast extract. The optimum culture conditions were initial pH 8.5, temperature 35 degrees C and cultivation time 36 h. Enzyme activity of culture filtrate to 0.5% galactomannan polysaccharide was 96 IU/mL per minute at pH 6.0 and 50 degrees C for 10 min. The optimum pH and temperature for enzyme action were 6.0 and 50 degrees C respectively. The enzyme was stable below 50 degrees C and pH 5.0-10.0. The enzyme hydrolyzed konjak powder and locust bean gum to form oligosaccharides.