| 摘要: |
| 为研究Rsx复合体中RsxC亚基在大肠杆菌中的生理功能及其对细胞代谢的影响，本研究构建pET30a-rsxC重组表达载体并转化大肠杆菌E. coli BL21(DE3)，经IPTG诱导表达后，在改良M9Y培养基中培养，通过高效液相色谱法测定葡萄糖消耗量及乳酸、乙酸、乙醇等代谢产物含量，并检测细胞内NADH水平。结果表明，pET30a-rsxC重组载体构建成功，RsxC蛋白获得表达。与空载对照相比，过表达菌株在各时间点的OD600值均显著升高，葡萄糖消耗速率加快；乳酸生成无持续性响应，而乙酸和乙醇产量显著增加；NADH/(NAD+ + NADH)比值自24 h起升高，36 h时增加率达424.0%，48 h时仍保持293.3%的优势。本研究证实RsxC过表达通过提升胞内NADH水平、改变氧化还原状态，促进细胞生长并驱动代谢流向乙酸和乙醇途径。该结果为氧化还原代谢工程提供了新的理论靶点。 |
| 关键词: RsxC亚基 NADH 氧化还原 过表达 大肠杆菌 |
| DOI： |
| 投稿时间：2026-05-17修订日期：2026-06-16 |
| 基金项目:广西自然科学基金重点项目（2024JJB160132）；广西壮族自治区大学生创新创业培训计划项目（202510593010）；广西青苗人才补助科研启动经费（202402030） |
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| Effects of RsxC Overexpression on Metabolic Performance and NADH Levels in Escherichia coli |
|
HE YAN, GUO HAO, YI JIAMIN, HUANG MENGHAN, LIU QIANGQIANG, WEI YUTUO, PAN SHIYOU
|
| (Guangxi University) |
| Abstract: |
| To investigate the physiological function of the RsxC subunit from the Rsx complex in Escherichia coli and its effects on cellular metabolism, the recombinant expression vector pET30a-rsxC was constructed and transformed into E. coli BL21(DE3). After IPTG induction, the cells were cultured in modified M9Y medium. Glucose consumption, levels of major fermentation products (lactate, acetate, ethanol), and intracellular NADH levels were measured. The results showed that the recombinant vector pET30a-rsxC was successfully constructed and RsxC protein was expressed. Compared with the empty vector control, the OD600 values of the overexpression strain were significantly higher at all time points, and the glucose consumption rate was accelerated. No sustained effect on lactate production was observed, whereas acetate and ethanol production were significantly increased. The NADH/(NAD+ + NADH) ratio increased after 24 h, with an increase rate of 424.0% at 36 h and maintained a 293.3% advantage at 48 h. This study confirms that RsxC overexpression promotes cell growth and drives metabolic flux toward acetate and ethanol pathways by elevating intracellular NADH levels and altering the cellular redox state. These findings provide a new theoretical target for redox?based metabolic engineering. |
| Key words: RsxC subunit NADH redox overexpression Escherichia coli |
