Alexandre G, Greer S E, Zhulin I B
Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA.
J Bacteriol. 2000 Nov;182(21):6042-8. doi: 10.1128/JB.182.21.6042-6048.2000.
Energy taxis encompasses aerotaxis, phototaxis, redox taxis, taxis to alternative electron acceptors, and chemotaxis to oxidizable substrates. The signal for this type of behavior is originated within the electron transport system. Energy taxis was demonstrated, as a part of an overall behavior, in several microbial species, but it did not appear as the dominant determinant in any of them. In this study, we show that most behavioral responses proceed through this mechanism in the alpha-proteobacterium Azospirillum brasilense. First, chemotaxis to most chemoeffectors typical of the azospirilla habitat was found to be metabolism dependent and required a functional electron transport system. Second, other energy-related responses, such as aerotaxis, redox taxis, and taxis to alternative electron acceptors, were found in A. brasilense. Finally, a mutant lacking a cytochrome c oxidase of the cbb(3) type was affected in chemotaxis, redox taxis, and aerotaxis. Altogether, the results indicate that behavioral responses to most stimuli in A. brasilense are triggered by changes in the electron transport system.
能量趋性包括趋氧性、趋光性、氧化还原趋性、对替代电子受体的趋性以及对可氧化底物的趋化性。这种行为类型的信号源自电子传递系统。能量趋性作为整体行为的一部分，在几种微生物物种中得到了证实，但在其中任何一种中都未表现为主要决定因素。在本研究中，我们表明，在巴西固氮螺菌这种α-变形杆菌中，大多数行为反应都是通过这种机制进行的。首先，发现对固氮螺菌栖息地典型的大多数化学效应物的趋化性依赖于代谢，并且需要一个功能性的电子传递系统。其次，在巴西固氮螺菌中发现了其他与能量相关的反应，如趋氧性、氧化还原趋性以及对替代电子受体的趋性。最后，一个缺乏cbb(3)型细胞色素c氧化酶的突变体在趋化性、氧化还原趋性和趋氧性方面受到影响。总之，结果表明巴西固氮螺菌对大多数刺激的行为反应是由电子传递系统的变化触发的。
