BACKGROUND L-ornithine is a valuable amino acid with a wide range of applications in the pharmaceutical and food industries. However, the production of L-ornithine by fermentation cannot compete with other methods, because of the low titers produced with this technique. Development of fermentation techniques that result in a high yield of L-ornithine and efficient strategies for improving L-ornithine production are essential. RESULTS This study demonstrates that tween 40, a surfactant promoter of the production of glutamate and arginine, improves L-ornithine production titers in engineered C. glutamicum S9114. The intracellular metabolism under tween 40 triggered fermentation conditions was explored using a quantitative proteomic approach, identifying 48 up-regulated and 132 down-regulated proteins when compared with the control. Numerous proteins were identified as membrane proteins or functional proteins involved in the biosynthesis of the cell wall. Modulation of those genes revealed that the overexpression of CgS9114_09558 and the deletion of CgS9114_13845, CgS9114_02593, and CgS9114_02058 improved the production of L-ornithine in the engineered strain of C. glutamicum Orn8. The final strain with all the exploratory metabolic engineering manipulations produced 25.46 g/L of L-ornithine, and a yield of 0.303 g L-ornithine per g glucose, which was 30.6% higher than that produced by the original strain (19.5 g/L). CONCLUSION These results clearly demonstrate the positive effect of tween 40 addition on L-ornithine accumulation. Proteome analysis was performed to examine the impact of tween 40 addition on the physiological changes in C. glutamicum Orn8 and the results showed several promising modulation targets for developing L-ornithine-producing strains.

中文翻译：

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蛋白质组学分析指导了谷氨酸棒杆菌S9114的基因工程，以补间40触发L-鸟氨酸生产的改善。

背景技术左旋鸟氨酸是一种有价值的氨基酸，在制药和食品工业中具有广泛的应用。然而，通过发酵生产L-鸟氨酸不能与其他方法竞争，因为该技术产生的滴度很低。发酵技术的发展对提高L-鸟氨酸的产量和提高L-鸟氨酸产量的有效策略至关重要。结果这项研究表明，吐温40是谷氨酸和精氨酸生成的表面活性剂促进剂，可改善工程化谷氨酸棒杆菌S9114中L-鸟氨酸的生产效价。使用定量蛋白质组学方法探索了40个触发的发酵条件下的细胞内代谢，与对照组相比，鉴定了48个上调蛋白和132个下调蛋白。鉴定出许多蛋白为参与细胞壁生物合成的膜蛋白或功能蛋白。这些基因的调节显示，CgS9114_09558的过度表达和CgS9114_13845，CgS9114_02593和CgS9114_02058的缺失提高了谷氨酸棒杆菌Orn8工程菌株中L-鸟氨酸的产生。经过所有探索性代谢工程操作的最终菌株产生了25.46 g / L的L-鸟氨酸，每克葡萄糖的产量为0.303 g L-鸟氨酸，比原始菌株（19.5 g / L）的产量高30.6％。 ）。结论这些结果清楚地表明，添加吐温40对L-鸟氨酸的积累具有积极作用。进行蛋白质组分析以检查添加吐温40对C生理变化的影响。