Corynebacterium glutamicum, industrially producing various bio-based organic acids, is often cultivated under abiotic stress conditions, such as low pH, which can reduce both cell growth and the yield of the target compound. Here, a response regulator from Deinococcus radiodurans, DR1558, was introduced into a recombinant C. glutamicum strain expressing lysine decarboxylase (cadA) to enhance cadaverine production at acidic pHs. During batch cultivation under acidic conditions, 6.4 g/L of cadaverine was produced by the recombinant C. glutamicum strain expressing cadA and dr1558; this yield was 1.7-fold higher than that produced by a recombinant C. glutamicum strain expressing only cadA. Transcriptional analysis revealed altered expression levels of stress defense- and cadaverine biosynthesis-related genes in the recombinant C. glutamicum strain expressing dr1558. During fed-batch cultivation, the recombinant C. glutamicum strain expressing cadA and dr1558 showed a 2.4-fold increase in cadaverine production compared to that produced by the recombinant C. glutamicum strain expressing only cadA. The cell growth of C. glutamicum expressing both cadA and dr1558 increased markedly during fed-batch cultivation at acidic pH. These results indicated that the response regulator dr1558 altered the expression of genes involved in metabolic pathways and stress defense mechanisms in C. glutamicum.

谷氨酸棒杆菌在工业上生产各种生物基有机酸，通常在非生物胁迫条件下培养，例如低 pH 值，这会降低细胞生长和目标化合物的产量。在这里，来自耐辐射奇异球菌的反应调节剂DR1558 被引入到表达赖氨酸脱羧酶 ( cadA )的重组谷氨酸棒杆菌菌株中，以增强酸性 pH 下尸胺的产生。在酸性条件下分批培养期间，表达cadA和dr1558的重组谷氨酸棒杆菌菌株产生6.4g/L尸胺；该产量比重组谷氨酸棒杆菌产生的产量高 1.7 倍仅表达cadA 的菌株。转录分析显示在重组应力与国防和尸胺的生物合成相关的基因的改变的表达水平谷氨酸菌株表达dr1558。在补料-分批培养，重组谷氨酸棒杆菌菌株中表达的cadA和dr1558显示在尸胺生产了2.4倍的增加相比，由重组产生的谷氨酸棒杆菌菌株仅表达的cadA。表达cadA和dr1558的谷氨酸棒杆菌的细胞生长在酸性 pH 下分批补料培养期间显着增加。这些结果表明，响应调节因子dr1558改变了谷氨酸棒杆菌中参与代谢途径和应激防御机制的基因的表达。