Thermostable Lipase ofBacillus stearothermophilus: High-level Production, Purification, and Calcium-dependent Thermostability

An efficient expression system was developed for the production of the thermostable lipase from Bacillus stearothermophilus L1 in an Escherichia coli system. A structural gene corresponding to mature lipase was subcloned in the pET-22b(+) expression vector and its expression was induced by IPTG at 30°C in E. coli cells. The lipase activity in a cell-free extract was as high as 448,000 units/g protein, which corresponds to as much as 26% of the...