The production of alpha-amylase in batch and chemostat culture by Bacillus stearothermophilus.

The production of alpha-amylase (alpha-1,4-glucan 4-glucanohydrolase; EC 3.2.1.1) by a strain of Bacillus stearothermophilus isolated from leaf litter was investigated in a tryptone-maltose medium at 55 degrees C in batch and chemostat culture. Amylase production was growth-limited and restricted to the exponential phase in batch culture. The enzyme yield was reduced by 40% when the culture pH was maintained at pH 7.2. Amylase production in chemostat culture was influenced by the growth rate throughout the dilution rate range used.