Studies on amylase activity of an amylolytic bacterium isolated from estuarine soil

Abstract

Diverse microscopic, macroscopic and biochemical analysis of a starch degrading amylolytic bacterial strain isolated from the soil sample of Rajakkamangalam estuary, Kanyakumari district, Tamil Nadu, India, revealed its identity to the genus Bacillus. Maximum growth was observed at 12 h when the bacteria was cultured in  minimal agar media with 2% starch maintained for 12 h, at 37°C and pH 5.5, 7.5 and 8.5. Highest enzyme  action as revealed by glucose production in the media was observed at pH 8.0, temperature 30°C and in the presence of 10 mM calcium (Ca). Enzyme activity gradually got reduced with the addition of increasing  concentrations of ethylenediaminetetraacetic acid (EDTA), confirming the need for calcium for enzyme action. The amylase produced in the medium was isolated by centrifugation and partially purified by ammonium sulphate fractionation followed by dialysis.

Key words: Amylase, bacteria, amylase activity, pH sensitivity, estuarine soil.