Characterization of a thermostable, CaCl2-activated and raw-starch hydrolyzing alpha-amylase from Bacillus licheniformis AT70: Production under solid state fermentation by utilizing agricultural wastes

Publication date: Available online 5 July 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Saideh Afrisham, Arastoo Badoei-Dalfard, Abdolhamid Namaki-Shoushtari, Zahra Karami B. licheniformis AT70 which produced a thermophilic, raw-starch degrading alpha-amylase was isolated from Gorooh hot springs in Kerman province. Maximum production of AT70 alpha-amylase was obtained in the presence of starch (as a carbon source) and ammonium chloride (as a nitrogen source) with 388 and 329U/ml enzyme yield, respectively. SSF was also carried out using various agricultural and kitchen wastes and results showed that the maximum yield of AT70 alpha-amylase production was obtained by date waste and wheat bran, respectively (10%, w/v). The thermal stability of the AT70 alpha-amylase was increased about 2.5 folds at 60°C. AT70 alpha-amylase showed the maximum activity at 1.5M NaCl by 42% and local detergent Shooma enhanced the alpha-amylase activity about 34%, compared to control. Furthermore, AT70 alpha-amylase exhibited remarkable hydrolytic activity in a range of 14-20% (w/v) of raw corn starch at 55°C. These results indicated that AT70 alpha-amylase has great potential applications for the raw-starch degrading. Graphical abstract

Source: Journal of Molecular Catalysis B: Enzymatic - July 5, 2016 Category: Biochemistry Source Type: research