A thermoactive α-amylase from a Bacillus sp. isolated from CSMCRI salt farm

Abstract

Amylases are the most important hydrolytic enzymes for starch-based industries. It is desirable that α-amylases should be active at high temperature of gelatinization (100–110 °C) and liquefaction (80–90 °C) to economize processes. Therefore, thermostable and thermoactive enzyme from natural bacterial strain would have wide industrial importance. In the present study a highly thermoactive and thermostable amylase producing Bacillus sp. was isolated from experimental salt farm of Central Salt and Marine Chemicals Research Institute, yielding 452 U ml −1 amylase in medium containing (%) NaCl 0.5, peptone 0.5, beef extract 0.3, starch 1.0 at 37 °C, pH 7.0 after 48 h of incubation. Maximum activity of amylase was observed at pH 8.0 and 110 °C temperature. The crude enzyme was highly active between pH 6.0 and 11.0 and observed to be active and thermostable after 30 min of incubation at 60 °C. These properties indicated that the isolated α-amylase enzyme is suitable for starch liquefaction and other food processing.