Van Spanning R J, de Boer A P, Reijnders W N, De Gier J W, Delorme C O, Stouthamer A H, Westerhoff H V, Harms N, van der Oost J
Department of Microbial Physiology, Vrije Universiteit, Amsterdam, Netherlands.
J Bioenerg Biomembr. 1995 Oct;27(5):499-512. doi: 10.1007/BF02110190.
Paracoccus denitrificans is a facultative anaerobic bacterium that has the capacity to adjust its metabolic infrastructure, quantitatively and/or qualitatively, to the prevailing growth condition. In this bacterium the relative activity of distinct catabolic pathways is subject to a hierarchical control. In the presence of oxygen the aerobic respiration, the most efficient way of electron transfer-linked phosphorylation, has priority. At high oxygen tensions P. denitrificans synthesizes an oxidase with a relatively low affinity for oxygen, whereas under oxygen limitation a high-affinity oxidase appears specifically induced. During anaerobiosis, the pathways with lower free energy-transducing efficiency are induced. In the presence of nitrate, the expression of a number of dehydrogenases ensures the continuation of oxidative phosphorylation via denitrification. After identification of the structural components that are involved in both the aerobic and the anaerobic respiratory networks of P. denitrificans, the intriguing next challenge is to get insight in its regulation. Two transcription regulators have recently been demonstrated to be involved in the expression of a number of aerobic and/or anaerobic respiratory complexes in P. denitrificans. Understanding of the regulation machinery is beginning to emerge and promises much excitement in discovery.
反硝化副球菌是一种兼性厌氧菌，能够根据当前的生长条件在数量和/或质量上调整其代谢结构。在这种细菌中，不同分解代谢途径的相对活性受到分级控制。在有氧存在的情况下，有氧呼吸作为电子传递偶联磷酸化的最有效方式具有优先性。在高氧张力下，反硝化副球菌合成一种对氧亲和力相对较低的氧化酶，而在氧限制条件下，一种高亲和力氧化酶会特异性诱导产生。在厌氧条件下，具有较低自由能转换效率的途径会被诱导。在有硝酸盐存在的情况下，多种脱氢酶的表达确保了通过反硝化作用继续进行氧化磷酸化。在鉴定出参与反硝化副球菌有氧和厌氧呼吸网络的结构成分后，接下来有趣的挑战是深入了解其调控机制。最近已证明两种转录调节因子参与反硝化副球菌中多种有氧和/或厌氧呼吸复合物的表达。对调控机制的理解正在逐渐形成，并有望在发现过程中带来许多令人兴奋的成果。
