Thermostable α-amylase and α-galactosidase production from the thermophilic and aerobic Bacillus sp.JF strain

Abstract

Extracellular thermostable α-amylase (EC 3.2.1.1) and intercellular α-galactosidase (EC 3.2.1.22) from one fermentation of a thermophilic and aerobic Bacillus sp.JF 2 strain were studied and modelled. The cell growth of the thermophilic Bacillus sp.JF 2 strain could be expressed by the Monod model, the μ max was 0.084/h, the activation energy for cell growth and death was E g=7.42 and E d=−18.8 cal/g mol K. The thermostable α-amylase production was expressed by a model combining growth-associated and non-growth-associated models. Intercellular α-galactosidase production was expressed by the growth-associated model; and the relationship equation between the substrate, cell growth, and two enzyme production was also defined, and the all constants were defined.