In this study, the response regulator DR1558 from Deinococcus radiodurans was overexpressed in recombinant Corynebacterium glutamicum with lysine decarboxylase (ldcC). The recombinant C. glutamicum strain overexpressing dr1558 and ldcC produced 5.9 g/L of cadaverine by flask cultivation, whereas the control strain overexpressing only ldcC produced 4.5 g/L of cadaverine. To investigate the mechanism underlying the effect of DR1558, the expression levels of genes related to central metabolism and lysine-biosynthesis were analyzed by quantitative-real time polymerase chain reaction. The results showed that phosphoenolpyruvate carboxykinase (pck) was downregulated, and pyruvate kinase (pyk) and other lysine biosynthesis genes were upregulated. Furthermore, in fed-batch fermentation, C. glutamicum coexpressing dr1558 produced 25.14 g/L of cadaverine, a 1.25-fold increase in concentration relative to the control. These results suggested that the heterologous expression of dr1558 may improve the production of biorefinery products by recombinant C. glutamicum.

在这项研究中，来自耐辐射奇球菌的反应调节剂 DR1558 在带有赖氨酸脱羧酶 ( ldcC ) 的重组谷氨酸棒杆菌中过表达。通过烧瓶培养，过表达dr1558和ldcC的重组谷氨酸棒杆菌菌株产生了5.9g/L的尸胺，而仅过表达ldcC的对照菌株产生了4.5g/L的尸胺。为了研究 DR1558 作用的机制，通过定量实时聚合酶链反应分析了与中枢代谢和赖氨酸生物合成相关的基因的表达水平。结果表明，磷酸烯醇丙酮酸羧激酶（ pck ）下调，丙酮酸激酶（ pyk ）等赖氨酸生物合成基因上调。此外，在补料分批发酵中，共表达dr1558的谷氨酸棒杆菌产生了25.14g/L的尸胺，相对于对照，浓度增加了1.25倍。这些结果表明dr1558的异源表达可以提高重组谷氨酸棒杆菌生物精炼产品的产量。