Müller-Kraft G, Babel W
Z Allg Mikrobiol. 1983;23(3):181-7. doi: 10.1002/jobm.3630230306.
Commonly the TCA cycle fulfils an anabolic and a catabolic function in case of aerobic chemoorganoheterotrophic nutrition. In methylotrophic growth the TCA cycle is dispensable as a bioenergetic pathway. This is reflected by properties of citrate synthase in facultative methylotrophic bacteria. Two citrate synthases, a "chemoorganoheterotrophic" one, which is inhibited by NADH (or ATP in Acetobacter MB 58), and a "methylotrophic" one, which is not or less affected by energy indicators, were found in Pseudomonas oleovorans, Pseudomonas MS, Pseudomonas MA, and Acetobacter MB 58. The concentration of these citrate synthases depends on the manner of nutrition. Bacteria with ICL-negative-variant of the serine pathway and with ribulosebisphosphate pathway seem to possess only a "chemoorganoheterotrophic" citrate synthase. Possibly the anabolic function of this citrate synthase can be realized by metabolites.
在有氧化学有机异养营养的情况下，三羧酸循环通常兼具合成代谢和分解代谢功能。在甲基营养型生长中，三羧酸循环作为生物能量途径是可有可无的。这在兼性甲基营养型细菌中柠檬酸合酶的特性上得到了体现。在食油假单胞菌、假单胞菌MS、假单胞菌MA和醋杆菌MB 58中发现了两种柠檬酸合酶，一种是“化学有机异养型”柠檬酸合酶，它被NADH（或醋杆菌MB 58中的ATP）抑制，另一种是“甲基营养型”柠檬酸合酶，它不受或较少受能量指标的影响。这些柠檬酸合酶的浓度取决于营养方式。具有丝氨酸途径ICL阴性变体和核酮糖二磷酸途径的细菌似乎只拥有一种“化学有机异养型”柠檬酸合酶。这种柠檬酸合酶的合成代谢功能可能通过代谢物来实现。
