aveD基因失活提高阿维菌素工业菌株B组分产量

目的 破坏除虫链霉菌aveD基因,提高阿维菌素B1a的发酵单位.方法 将aveD基因内部364bp的SmaⅠ-SmaⅠ片段以相反的方向插入到原位置,构建重组质粒pUAmT-D7,并转化到阿维菌素工业生产菌Streptinomyces avermitilis G-8,筛选得到ave基因失活的基因工程菌G8-17.结果 发酵结果表明,G8-17不产维菌素A组分,而B组分的发酵单位则有相应的提高,其中有效组分B1a的发酵单位提高了33.6％.结论 aveD基因内部片段倒位没有影响下游与之共转录的基因aveF的表达,同时能有效阻断阿维菌素A组分的产生,提高B组分的发酵单位.

Gene Disruption of aveD Enhanced the Yield of Avermectin B in Industrial Strain

Objective Thereby enhance the yield of avermectin Bla by gene disruption of aveD. Methods 340 base pair of Sma I - Sma I DNA fragment was knocked down by inserted into the original site with reversed direction to obtain plasmid pUAmT-D7. The plasmid was then transformed into avermectin industrial production strain Streptinomyces avermitilis G-8, and the mutant of aveD disruption G8~l 7 was screened. Results Fermentation experiments showed that the yield of avermectin B components was enhanced in fermentation titer without producing any avermectin A components in the mutant G8-17. The effective component Bla was enhanced by 33.6%. Conclusion The inversion of internal fragment in aveD did not influence the expression of the co-transcribing downstream gene aveF. Meanwhile, it could efficiently block the transformation from avermectin B to A components to enhance the fermentation titer of avermectin B.