Bi-phasic production of a-amylase of Bacillus flavothermusin batch fermentation

Abstract

The facultative thermophile, Bacillus flavothermus, produced highest a-amylase activity (28.6 units/ml) with lactose (4%, w/v) and Yeatex (2%, w/v) and an initial pH 6.0 at 55°C. In batch fermentation, biomass and a-amylase activity peaked twice. In the first of these growth cycles the organism utilised the nitrogen source, Yeatex, and maximum enzyme was associated with cell lysis. In the second growth phase the carbohydrate source, lactose, was utilised and enzyme peaked in the early stages of growth.