High-level expression of thermo-alkaline lipase in under the control of different promoters.

In this study, 15 methanol-inducible and 9 constitutive promoters were used to drive the expression of lipase (TDL) in . Of the 15 methanol-inducible promoters, formaldehyde dehydrogenase promoter (P) showed the highest efficiency in driving lipase production, followed by alcohol oxidase 1 (P) and dihydroxyacetone synthase (P) promoters. The maximum lipase activity of transformants with P, P and P promoters in 5-l bioreactor was 27,076, 24,159 and 22,342 U/ml, respectively. For the nine constitutive promoters, glycosyl phosphatidyl inositol-anchored protein promoter (P) produced the highest amount of lipases in a medium containing glucose or glycerol as the only carbon source, followed by mitochondrial alcohol dehydrogenase isozyme (P) and glyceraldehyde-3-phosphate dehydrogenase (P) promoters. The maximum lipase yields in 5-l bioreactors under the control of P, P and P promoters were 17,353, 15,046 and 14,276 U/ml, respectively. The result of this study not only identifies a few highly efficient promoters for the heterologous expression of TDL in , but also casts some insight into the optimization of protein production in heterologous systems.