alpha-Amylase production by free and immobilized Bacillus subtilis

The effect of glucose on the alpha-amylase production by Bacillus subtilis ATCC-21556 was studied. Initial glucose concentrations up to 20 g/L were fo und to be directly proportional to the specific alpha-amylase production in an immobilized-cell batch system, whereas a free-cell batch system present ed an inversely proportional relationship with the initial glucose concentr ation. This might be owing to the alpha-amylase repression by the glucose p resent in the culture medium. Three hundred eighty-five percent of the spec ific a-amylase production with the free-cell system was produced by the imm obilized-cell batch culture.