R. KOKILA AND S. MRUDULA
Abstract
Thermophilic bacterium that secretes amylase was isolated from soil and identified as Bacillus sp. The strain was cultivated in submerged fermentation and produced 296 units of amylase per ml of culture broth containing 0.2% soluble starch as a carbon source. The most important factors such as substrate concentration, inoculum size, temperature, pH, incubation time and various carbon, nitrogen sources that influence the enzyme production were optimized. The optimum substrate concentration, temperature, pH and incubation period were found to be 3.0%, 55 o C, 8.0 and 24 hours respectively for maximum enzyme production. Among different carbon, nitrogen and trace elements supplemented, fructose, yeast extract, calcium and sodium chloride respectively enhanced production. Under the optimum parameters, the strain produced 400 units of amylase per ml of culture broth which is 35% more than an un optimized medium.