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多杀菌素(spinosad)为土壤放线菌刺糖多孢菌(Saccharopolyspora spinosa)经有氧发酵产生的次级代谢产物,是一种广谱、高效、低毒的生物杀虫剂,已在农药、兽药和卫生用药领域得到广泛应用。刺糖多孢菌对长效碳源淀粉的利用能力很低,这给多杀菌素的工业化发酵带来了困难。本研究在刺糖多孢菌高产菌株ASAGF73中表达阿维链霉菌(Streptomyces avermitilis)的麦芽糖转运系统基因(maltose transporter gene)mal E、mal F和mal G,以提高菌株利用淀粉的能力。将整合型载体p SET152::mal EFG通过接合转移转化ASAGF73,获得的转化子成功表达了mal EFG基因。单一碳源发酵实验结果表明,转化子利用糊精和麦芽糖的能力显著提高。以糊精或麦芽糖为单一碳源的条件下,mal EFG的表达显著促进了菌体生物量的提高,进而提高多杀菌素的产量。本研究对于以淀粉为主要碳源发酵生产多杀菌素的工艺研究具有理论指导意义及应用价值。
Spinosad, a secondary metabolite produced by aerobic fermentation of soil actinomycete Saccharopolyspora spinosa, is a broad-spectrum, high-efficiency and low-toxicity bio-pesticide that has been widely used in pesticides , Veterinary drugs and health medicine has been widely used. The ability of Saccharomyces cerevisiae to utilize long-term carbon source starch is very low, which brings difficulties to the industrialization of spinosad fermentation. In this study, the maltose transporter genes mal E, mal F and mal G of Streptomyces avermitilis were expressed in the high-yield Strain of Saccharopolyspora spinosa ASAGF73 to enhance the ability of the strain to utilize starch. The transformant obtained by transforming integrin p SET152 :: mal EFG to ASAGF73 by junctional transfer successfully expressed the mal EFG gene. Single carbon source fermentation experiment results show that the ability of transformants to use dextrin and maltose significantly increased. Under the condition of dextrin or maltose as the sole carbon source, the expression of mal EFG significantly promoted the biomass of the cells and then increased the production of spinosad. This study has theoretical significance and application value for the study of spinosad production by starch as the main carbon source.