High-level expression of Thermomyces dupontii thermo-alkaline lipase in Pichia pastoris under the control of different promoters

In this study, 15 methanol-inducible and 9 constitutive promoters were used to drive the expression of Thermomyces dupontii lipase (TDL) in Pichia pastoris . Of the 15 methanol-inducible promoters, formaldehyde dehydrogenase promoter (P FLD1 ) showed the highest efficiency in driving lipase production, followed by alcohol oxidase 1 (P AOX1 ) and dihydroxyacetone synthase (P DAS1 ) promoters. The maximum lipase activity of transformants with P FLD1 , P AOX1 and P DAS1 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 GCW14 ) 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 0472 ) and glyceraldehyde-3-phosphate dehydrogenase (P GAP ) promoters. The maximum lipase yields in 5-l bioreactors under the control of P GCW14 , P 0472 and P GAP 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 P. pastoris , but also casts some insight into the optimization of protein production in heterologous systems.