摘要
为检测ctcK基因的功能,利用基因工程技术在金色链霉菌J13(Streptomyces aureofaciens J13)上构建ctcK基因缺失工程菌SK12(ΔctcK),并分析了其次级代谢产物的变化.经质谱分析显示,工程菌SK12代谢物中检测到去甲基金霉素m/z=465.10[M+H]~+的分子离子峰,但未检测到金霉素m/z=479.12[M+H]~+的分子离子峰,这与出发菌J13代谢物的检测结果相反.结果表明,ctcK基因的失活阻断了金霉素的生物合成代谢流,使工程菌SK12主要积累去甲基金霉素,显示ctcK基因参与金霉素C-6位甲基化.本研究初步阐明了ctcK基因的功能,同时获得了一株主产去甲基金霉素的工程菌.
In order to detect the function of ctcK,the ctcK deletion mutant S. aureofaciens SK12( ΔctcK) was constructed in S. aureofaciens J13 by genetic engineering. Changes of its secondary metabolites were analyzed. The molecular ion peak of demethylchlortetracycline( m / z = 465. 10 [M + H]~+) instead of chlortetracycline( m/z =479. 12 [M + H]~+) was detected in the metabolites of mutant strain SK12 by MS analyses. This is in contrast to the detection result of metabolites of parent strain J13. These results indicate that the inactivation of ctcK interdicts chlortetracycline biosynthesis flow and lead to the main accumulation of demethylchlortetracycline in mutant strain SK12,revealing the successful methylation of C-6 of chlortetracycline with ctcK involved. In this study,the function of the ctcK was preliminarily elucidated. An engineered bacteria that mainly produces monocomponent demethylchlortetracycline has been simultaneously obtained.
引文
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