Improvement on Extracellular Production of Recombinant Burkholderia cepacia Lu10-1 Lipase by Escherichia coli

The purpose of this study was to investigate several strategies on enhancing extracellular production of recombinant lipase from Burkholderia cepacia Lu10-1 in recombinant Escherichia coli BL21(DE3). In the present study, a fed-batch fermentation strategy for the excellular production of lipase by E. coli has been established. First of all, different induction methods (including selection of inducers, inducer concentration, induction temperature and induction time) were investigated and the results indicated that these factors played an important role in lipase production. When induced by 0.8 g L^-1 h^-1 lactose at 30°C and at a OD₆₀₀ of 30, the lipase activity in the culture medium could achieve 58 U mL^-1. Moreover, addition of glycine and calcium ions can increase the extracellular yield of lipase. With supplementation of the culture with 0.5% (w/v) glycine and 2.5 mM Ca²⁺, the maximum extracellular activity of lipase could reach 85 U mL^-1, which was 2.1 fold higher than that of the control. This study might provide fermentation strategy for the extracellular production of other heterogonous proteins expressed in E. coli.