基于转录组分析的染色体大片段缺失及其对井冈霉素高产菌株的影响  

Effect of transcriptome-based large region deletion on validamycin A overproduction by Streptomyces hygroscopicus var. jinggangensis TL01

作　　者：芦晨阳[1,2] 吴杭[3] 苏秀榕[1] 白林泉[2] 

机构地区：[1]宁波大学海洋学院,浙江宁波315211 [2]上海交通大学微生物代谢国家重点实验室,上海200240 [3]安徽大学生命科学学院,安徽合肥230029

出　　处：《微生物学报》2017年第7期1038-1048,共11页Acta Microbiologica Sinica

基　　金：国家自然科学基金(31070070)~~

摘　　要：【目的】测试大片段删减低转录区域对菌体生长和井冈霉素产量的影响。【方法】通过转录组分析,选择染色体上连续的基因低转录区域进行大片段缺失,通过Cre-loxP位点特异性重组得到1.2 Mb片段缺失突变株LCY-4。HPLC检测缺失株井冈霉素产量的变化,并测定干重绘制生长曲线。【结果】通过转录组分析,我们在井冈霉素高产菌株TL01染色体左侧末端发现了1.9 Mb的连续基因低转录区,使用Cre-loxP系统对其中的1.2 Mb区域进行大片段缺失,成功得到了1.2 Mb缺失突变株LCY-4。和出发菌株TL01相比,缺失突变株LCY-4中井冈霉素发酵产量基本保持不变,生物量有显著提高,最高增幅达到44%。【结论】1.2 Mb区域的成功缺失,意味着基于转录组分析寻找连续的基因低转录区域并加以缺失的策略的可行性。1.2 Mb片段缺失对菌体生物量积累具有明显促进作用,为后续将其开发成氨基环醇类药物异源表达的通用高产宿主奠定了基础。[Objective] The effect of continuous low-expression region on validamycin A titer and biomass was evaluated through gene deletion experiments. [Methods[ The deletion boundaries of large chromosome region were identified via transcriptome analysis. Meanwhile, deletion mutant was obtained via Cre-loxP system, titer of validamycin A was detected by HPLC and, biomass was represented by dry cell weight. [Results] The 1.2 Mb large region identified via transcriptome analysis was successfully deleted by Cre-loxP system. In comparison with parent strain TL01, deletion of 1.2 Mb region increased the biomass by 44% and showed no effect on validamycin A titer. [Conclusion] The strategy developed here can be applied to identify deletion boundaries of large chromosome region, and mutant of 1.2 Mb region deletion showed potential as host for heterologous expression of aminocyclitol biosynthetic gene clusters.

关 键 词：井冈霉素 转录组 Cre-loxP系统 大片段缺失 

分 类 号：Q78[生物学—分子生物学] Q93