• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Microbiology >Disruption of the Oxidative Pentose Phosphate Pathway Stimulates High-Yield Production Using Resting Corynebacterium glutamicum in the Absence of External Electron Acceptors
【24h】

Disruption of the Oxidative Pentose Phosphate Pathway Stimulates High-Yield Production Using Resting Corynebacterium glutamicum in the Absence of External Electron Acceptors

机译：氧化戊糖的破坏磷酸盐途径在没有外部电子受体的情况下使用休息的棒杆菌谷氨酸刺激高产产生

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Identifying and overcoming the limitations preventing efficient high-yield production of chemicals remain important tasks in metabolic engineering. In an attempt to rewire Corynebacterium glutamicum to produce ethanol, we attained a low yield (63% of the theoretical) when using resting cells on glucose, and large amounts of succinate and acetate were formed. To prevent the by-product formation, we knocked out the malate dehydrogenase and replaced the native E3 subunit of the pyruvate dehydrogenase complex (PDHc) with that from Escherichia coli , which is active only under aerobic conditions. However, this tampering resulted in a 10-times-reduced glycolytic flux as well as a greatly increased NADH/NAD~(+) ratio. When we replaced glucose with fructose, we found that the glycolytic flux was greatly enhanced, which led us to speculate whether the source of reducing power could be the pentose phosphate pathway (PPP) that is bypassed when fructose is metabolized. Indeed, after shutting down the PPP by deleting the zwf gene, encoding glucose-6-phosphate dehydrogenase, the ethanol yield on glucose increased significantly, to 92% of the theoretical. Based on that, we managed to rechannel the metabolism of C. glutamicum into d-lactate with high yield, 98%, which is the highest that has been reported. It is further demonstrated that the PPP-inactivated platform strain can offer high-yield production of valuable chemicals using lactose contained in dairy waste as feedstock, which paves a promising way for potentially turning dairy waste into a valuable product.IMPORTANCE The widely used industrial workhorse C. glutamicum possesses a complex anaerobic metabolism under nongrowing conditions, and we demonstrate here that the PPP in resting C. glutamicum is a source of reducing power that can interfere with otherwise redox-balanced metabolic pathways and reduce yields of desired products. By harnessing this physiological insight, we employed the PPP-inactivated platform strains to produce ethanol, d-lactate, and alanine using the dairy waste whey permeate as the feedstock. The production yield was high, and our results show that inactivation of the PPP flux in resting cells is a promising strategy when the aim is to use nongrowing C. glutamicum cells for producing valuable compounds. Overall, we describe the benefits of disrupting the oxidative PPP in nongrowing C. glutamicum and provide a feasible approach toward waste valorization.
机译：识别和克服防止化学品高产高产生产的局限性仍然是代谢工程中的重要任务。在尝试将棒状杆菌谷氨酰胺重新加入谷氨酸以产生乙醇，在使用尿素上的静息细胞时，我们达到了低产量（理论的63％），并且形成大量的琥珀酸盐和乙酸盐。为了防止副产物形成，我们敲出了丙酸酯脱氢酶，并用来自大肠杆菌的大肠杆菌替换丙酮酸脱氢酶复合物（PDHC）的天然E3亚基，其仅在有氧条件下活性。然而，这种篡改导致10次降低的糖酵解助焊剂以及大大增加的NADH / NAD〜（+）比率。当我们用果糖取代葡萄糖时，我们发现糖酵解通量大大提高，这导致我们推测降低功率的源代谢时是否可以是旁路的磷酸磷酸盐途径（PPP）。实际上，通过删除ZWF基因来关闭PPP后，编码葡萄糖-6-磷酸脱氢酶，葡萄糖对葡萄糖的乙醇产量显着增加至约92％的理论。基于此，我们设法将C.谷氨酸的新陈代谢恢复为D-乳酸的高产率，98％，这是据报道的最高。进一步证明，PPP - 灭活平台应变可以使用乳制品中包含的乳酸作为原料的乳糖提供高产的有价值的化学品生产，这为潜在地将乳制品垃圾铺平为有价值的产品。以广泛使用的工业主营制作C.谷氨酰胺在非创造条件下具有复杂的厌氧代谢，并且在此证明静息C.谷氨酰胺的PPP是减少能力的源，其可以干扰其他氧化还原性代谢途径并降低所需产物的产量。通过利用这种生理洞察力，我们使用PPP - 失活平台菌株来生产乙醇，D-乳酸和丙氨酸，使用乳制品粉碎乳清渗透物作为原料。生产率高，我们的结果表明，当目的用于使用非学生C.谷氨酰胺细胞生产有价值的化合物时，静息细胞中PPP通量的失活是一种有希望的策略。总体而言，我们描述了破坏非创谷氨酸中氧化PPP的益处，并提供了一种可行的浪费储存方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号