Production, characterization and application of thermostable, alkaline α-amylase (AA11) from Bacillus cereus strain SP-CH11 isolated from Chilika Lake

An alkaliphile bacterial strain designated as CH11 was isolated from the sediments of Chilika Lake, Odisha. The isolate showed stupendous growth and production of alpha-amylase at pH 10.0. Through 16S rRNA gene based molecular technique this isolate was identified as Bacillus cereus strain SP-CH11 having GenBank Accession No. KT992791. Homogenous similar to 55 kDa extracellular alpha-amylase was extracted with 241.304, 26.26 and 3.2-fold acceleration in specific activity, purification fold and yield respectively. The alkaline alpha-amylase AA11 was further characterized. At pH 9.0 the purified enzyme AA11 was highly stable while retaining 88-100% functional viability at temperature range from 35 to 65 degrees C, confirming its thermostability nature. It showed stability with powdered and liquid detergents at 7 mg/mL and 100-fold dilutions respectively. AA11 efficiently removed the starch stain from cotton fabrics. The findings of this study indicate that the isolate CH11 is a source of novel alkaline alpha-amylase that has promising application in food and detergent industries. (C) 2019 Elsevier B.V. All rights reserved.