Molecular Biology and Genetic Department, Faculty of Science, Gebze Technical University, 41400, Gebze, Kocaeli, Turkey.
Curr Microbiol. 2019 Sep;76(9):1045-1054. doi: 10.1007/s00284-019-01719-3. Epub 2019 Jun 18.
ATP-dependent Lon protease plays important roles in different physiological processes, including cellular differentiation of the bacteria and is a part of an important stress response regulon (HspR/HAIR). In Streptomyces, biosynthesis of secondary metabolites starts with cellular differentiation and stress is one of the factor that affect metabolite production. To clarify the effect of Lon protease on secondary metabolite production, we constructed a recombinant strain of Streptomyces coelicolor A3(2) that has one extra copy of lon gene with its own promoter and transcriptional terminator in its genome. Expression of lon gene in the recombinant strain was determined by quantitative real time (RT-qPCR). Actinorhodin and undecylprodigiosin production of the recombinant cell was measured in liquid R2YE and it was found to produce about 34 times more actinorhodin and 9 times more undecylprodigiosin than the wild-type at 168 h of growth. Development of stable Streptomyces strains capable of producing high amounts of secondary metabolites is valuable for biotechnology industry. One extra copy of lon gene is enough to boost antibiotic production by S. coelicolor A3(2) and this change do not cause any metabolic burden in the cell.
依赖 ATP 的 Lon 蛋白酶在不同的生理过程中发挥着重要作用，包括细菌的细胞分化，并且是重要的应激反应调控子（HspR/HAIR）的一部分。在链霉菌中，次生代谢物的生物合成始于细胞分化，而应激是影响代谢产物产生的因素之一。为了阐明 Lon 蛋白酶对次生代谢物产生的影响，我们构建了一个链霉菌 A3(2)的重组菌株，该菌株在其基因组中有一个额外的 Lon 基因拷贝，带有其自身的启动子和转录终止子。通过定量实时（RT-qPCR）确定重组菌中 lon 基因的表达。在液体 R2YE 中测量重组细胞的放线紫红素和十一烷吡咯并红菌素的产量，发现其在 168 h 的生长时间内产生的放线紫红素比野生型多约 34 倍，十一烷吡咯并红菌素多 9 倍。开发能够产生大量次生代谢物的稳定链霉菌菌株对生物技术产业具有重要价值。Lon 基因的一个额外拷贝足以提高链霉菌 A3(2)的抗生素产量，并且这种变化不会给细胞带来任何代谢负担。
