High Production of Thermostable β-Galactosidase of Bacillus stearothermophilus in Bacillus subtilis

Abstract

By cloning the β-galactosidase gene of Bacillus stearothermophilus IAM11001 (ATCC 8005) into Bacillus subtilis , enzyme production was enhanced 50 times. β-Galactosidase could be purified to 80% homogeneity by incubating the cell extract of B. subtilis at 70°C for 15 min, followed by centrifugation to remove the denatured proteins. Because of its heat stability and ease of production, β-galactosidase is suitable for application in industrial processes.