Production of Alkaline Enzymes by Alkalophilic Microorganisms

Bacillus No. A–40–2 isolated from soil produced an alkaline amylase in alkaline media. The characteristic point of this microorganism was especially good growth in alkaline media, and no growth was detected in neutral media such as nutrient broth. The alkaline amylase of Bacillus No. A–40–2 was purified by DEAE-cellulose and hydroxyl apatite columns. The amylase was most active at pH 10.5 and stable pH was about 8.5. Calcium ion was effective to stabilize the enzyme especially at high temperatures. The sedimentation constant was about 3.8 S and molecular weight estimated by the Sephadex gel-filtration method was about 70,000. The enzyme was inactivated by urea, sodium laurylsulfate and sodium dodecylbenzene sulfonate. EDTA, PCMB and DFP did not show inhibitory effect. The enzyme hydrolyzed about 70% of starch and yielded glucose, maltose and maltotriose. If the enzyme is a single entity, this alkaline amylase is a type of saccharifying α-amylase.