was first time reported. We constructed the over-expression functional plusmids of phzD, phzE, phzF and phzG, and transformed them into Psedomonas sp. M18 for fermentation of PCA. The fermentation results indicated that in the four genes phzD had the most significant effect for the PCA biosynthesis for enhancing the PCA product by more than 30% by phzD over-expression pared to the control of strain bearing void plasmid. This illustrated that phzD played most important role in the pathway if only single gene was considered. The experiments of inoculation period and availability of oxygen indicated that the over-expression strains and wild type of Pseudomonas M18 had different requirements in cultural conditions. Using the ristiction of antisense RNA of phzD gene, the level of PCA product was greatly decreased in the fermentation experiments of Pseudomonas M18. Key Words: Pseudomonas sp. M18, PCA, phz gene cluster, over-expression, antisense RNA 目 录 第一章 绪论.................................................................................................................... 1 生物农药概况........................................................................................................... 1 生物农药的优越性........................................................................................... 1 生物农药的分类及发展现状........................................................................... 4 生物农药的发展前景....................................................................................... 6 新型生物农药申嗪霉素的研究进展........................................................................ 8 申嗪霉素的研究背景....................................................................................... 8 申嗪霉素的基本性质....................................................................................... 8 应用效果........................................................................................................... 9 植物根际促生细菌和 PCA 10 吩嗪化合物生物合成..........
