Bacillus sp. KCA102 capable of producing thermostable amylase in a short fermentation time (similar to 18-20 h) has been isolated from a soil sample. The performance of amylase during hydrolysis of starch has been studied using response surface methodology. The parameters under study have been categorized into two, viz., physical parameters (pH, temperature and time) and chemical parameters (amounts of substrate and enzyme). The optimal conditions of pH, temperature and time at which maximum amount of glucose formed were found to be 7.1, 57.5 degrees C and 25 min, respectively. The optimal amounts of substrate and enzyme for maximum hydrolysis were found to be 0.5% starch and 94 mU/ml of amylase, respectively. (c) 2004 Elsevier Ltd. All rights reserved.