微生物および生化学技術ジャーナル

概要

Characterization of Alkaliphilic, Surfactant Stable and Raw Starch Digesting A-Amylase from Bacillus subtilis Strain JS-16

Gopalakrishnan Menon, Kalpana Mody, Sumitra Datta and Bhavanath Jha

An alkali-thermophilic and surfactant stable α-amylase was obtained from Bacillus subtilis strain JS-16, isolated from sludge samples of a soda ash industry, located on west coast of Gujarat. It was active over a wide temperature range (30°C-80°C) exhibiting optimum activity at 50°C and pH 9.0. Unique feature of this amylase was two-fold enhancement of activity in SDS. Three-step purification yielded 15.16-fold purified enzyme with specific activity of 13.5 U/mg proteins. Km and Vmax were 10 mg/ml and 0.2 μmol/min/ml (11.56 μmol/ min/mg protein) respectively. Enzyme activity enhanced with Fe3+ but was strongly inhibited by Hg2+ ions. The amylase hydrolyzed 12% raw wheat starch and 5% corn starch granules after 12 h incubation. Surfactant stability, alkaliphilic nature, activity under wide temperature range and hydrolyses of raw starch makes this amylase a promising candidate for liquid detergent and starch industry.