Aerobic TMAO respiration in Escherichia coli
Aerobic TMAO respiration in Escherichia coli
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DOI：
10.1111/j.1365-2958.2007.05936.x
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发表时间：
2007-10-01
影响因子：
3.6
通讯作者：
Mejean, Vincent
中科院分区：
文献类型：
--
作者：
Ansaldi, Mireille;Theraulaz, Laurence;Mejean, Vincent
在没有氧气的情况下，大肠杆菌可以使用替代的外源电子受体，包括氧化三甲胺（TMAO），以产生能量。在这项研究中，我们表明，在其他厌氧呼吸系统，氧化三甲胺还原酶（Tor）系统的好氧和厌氧过程中表达。通过使用torA-lacZ融合和定量逆转录聚合酶链反应，我们建立了编码Tor系统的torCAD操纵子在TMAO存在下主要在指数期被诱导，并且最佳诱导需要一定水平的DNA超螺旋。我们还表明，氧气的存在既不能阻止Tor系统的生物合成，也不能阻止TMAO的还原。在需氧过程中TMAO还原的生理作用尚未确定，但我们的实验表明，碱性TMA生产可以通过增加培养物的pH值来增强生长条件。
In the absence of oxygen, Escherichia coli can use alternative exogenous electron acceptors, including trimethylamine oxide (TMAO), to generate energy. In this study, we showed that in contrast to the other anaerobic respiratory systems, the TMAO reductase (Tor) system was expressed during both aerobiosis and anaerobiosis. By using a torA-lacZ fusion and quantitative reverse transcription polymerase chain reaction, we established that the torCAD operon encoding the Tor system was induced in the presence of TMAO mainly during exponential phase, and that optimal induction required a certain level of DNA supercoiling. We also showed that the presence of oxygen prevented neither the biogenesis of the Tor system nor the reduction of TMAO. The physiological role of TMAO reduction during aerobiosis has not been yet established, but our experiments suggest that alkaline TMA production could enhance the growth conditions by increasing the pH of the culture.