Abstract:

The bsh1 gene was subcloned into expression vector pET28b and its product bile sale hydrolase(BSH) was overexpressed in Escherichia coli BL21. The appropriate value of each significant effect was noted with single factor experimental design. Effects of inducing time, isopropylthioDgalactoside. IPTG concentration, bile salt concentration and amount of medium on BSH activity were investigated by orthogonal test. After orthogonal experimental design, under the optimal condition, the specific activity of BSH was 817.73 U．

Key words: bile salt hydrolase, BSH, fermentation condition, single factor experimental design, orthogonal experimental design