Studies on combinatorial biosynthesis of taxadiene in Escherichia coli

OBJECTIVE To construct a metabolic pathway for producing taxadiene in Escherichia coli. METHODS The genes encoding isopentenyl diphosphate (IDP) isomerase, 1-deoxyxylulose 5-phosphate (DXP) synthase and the gene encoding geranylgeranyl diphosphate (GGDP) synthase were cloned using PCR from E. coli and Capsicum annuum, respectively. The fusion expression vector pAIG harboring the genes of IDP isomerase and GGDP synthase and the expression vector pSLB208/DXP bearing the gene of DXP synthase were constructed. Two expression plasmids and expression plasmid pETB3 harboring the gene of taxadiene synthase from Taxus chinensis were co-transformed into E. coli. The four genes were simultaneously expressed by inducing, and the metabolic products were analyzed by gas chromatography-mass spec-trometry (GC-MS) .RESULTS A metabolic pathway for producing taxadiene was established in the engineered E. cocli. The synthesis of taxadiene was detected by GC-MS analysis.CONCLUSION The intermediate of paclitaxel (Taxol) can be obtained by metabolic engineering. The strains developed in this study can serve as a platform for the production of some terpenoid compound while a terpene synthase gene is available.