Engineering taxol biosynthetic pathway for improving taxol yield in taxol-producing endophytic fungus EFY-21 (Ozonium sp.)

Key enzyme gene transformation is an ordinary and effective method to increase secondary metabolites of plants and microorganisms. In this work, a fungus expression vector (pV2+-TS-pAN7-1) containing taxadiene synthase gene (ts), a rate-limiting enzyme gene for taxol biosynthesis, was constructed and used in the transformation of taxol-producing endophytic fungus EFY-21. Southern blot analysis demonstrated the integration of the ts gene in the genome of independent transformants and one taxol-increased transgenic strain was screened out by LC-MS analysis. Reverse transcription - polymerase chain reaction (RT-PCR) results proved the over-expression of the ts gene in the transgenic strain. This study provides a possibility to improve the taxol yield of taxol-producing fungi by genetic engineering and a prospect for massive production of taxol by fungal fermentation. Key words: Taxol, taxol-producing fungi, transformation, taxadiene synthase (TS), LC-MS.