Optimization of the thermostable alkaline and Ca-dependent alpha-amylase production from Bacillus paralicheniformis by statistical modeling

A novel amylolytic enzyme producing thermoalkaliphilic bacteria was isolated and used in the present study since they are the source of industrially used enzymes. Isolated strain identified by morphological, physio-biochemical tests and the 16S rRNA gene sequence analysis. The optimal conditions of enzyme activity were determined. For higher -amylase production, the variables such as yeast extract, starch, CaCl 2 , (NH 4 ) 2 SO 4, NaCl and MgSO 4 in the a-amylase production medium and the temperature and pH were screened by Plackett–Burman design and optimised using response surface methodology (RSM). The optimal conditions were found to be 0.15 g/L for starch, 0.15 mg/L for CaCl 2 and 60 oC for temperature. By using RSM model, amylase production increase was achieved up to seven-fold. It is showed that this method can be utilised to optimize a-amylase production in a thermophilic bacteria such as Bacillus paralicheniformis .