Bioenergetics analysis of ammonia-oxidizing bacteria and the estimation of their maximum growth yield
Bioenergetics analysis of ammonia-oxidizing bacteria and the estimation of their maximum growth yield
复制标题
DOI：
10.1016/j.watres.2019.01.054
复制
发表时间：
2019-05-01
期刊：
影响因子：
12.8
通讯作者：
Ofiteru, Irina Dana
中科院分区：
文献类型：
--
作者：
Gonzalez-Cabaleiro, Rebeca;Curtis, Thomas Peter;Ofiteru, Irina Dana
目前公认的氨氧化细菌（AOB）的生物化学和生物能量学显示出低效的代谢：当一摩尔氨被氧化时，只有53.8%的能量释放，并且释放的电子中只有不到两个可以被引导到自养厌氧微生物。然而，矛盾的是，AOB似乎在具有挑战性的条件下茁壮成长：几乎在大多数好氧环境中容易生长，但在纯培养中存在有限的AOB。在这项研究中，一个全面的生物化学模型的代谢AOB。使用生物能量学计算并选择每个代谢步骤中消耗的能量的最小估计，该模型预测最高可能的真实产量为0.16 gBio/gN，当考虑细胞维持时，产量为0.13 gBio/gN。观察到的产率应始终低于这些值，但文献中的实验值范围在0.04和0.45 gBio/gN之间变化。在这项工作中，我们讨论了如果其他未考虑的替代能源存在于AOB的生物化学中，是否可以理解AOB生长产量的观测值的方差。我们分析了预测的最大生长产量的AOB的变化，考虑共代谢，使用羟胺作为底物，非生物氧化的NO，能量收集在单加氧酶或使用有机碳源。(C)2019作者爱思唯尔有限公司出版
The currently accepted biochemistry and bioenergetics of ammonia-oxidizing bacteria (AOB) show an inefficient metabolism: only 53.8% of the energy released when a mole of ammonia is oxidised and less than two of the electrons liberated can be directed to the autotrophic anabolism. However, paradoxically, AOB seem to thrive in challenging conditions: growing readily in virtually most aerobic environment, yet limited AOB exist in pure culture. In this study, a comprehensive model of the biochemistry of the metabolism of AOB is presented. Using bioenergetics calculations and selecting the minimum estimation for the energy dissipated in each of the metabolic steps, the model predicts the highest possible true yield of 0.16 gBio/gN and a yield of 0.13 gBio/gN when cellular maintenance is considered. Observed yields should always be lower than these values but the range of experimental values in literature vary between 0.04 and 0.45 gBio/gN. In this work, we discuss if this variance of observed values for AOB growth yield could be understood if other non-considered alternative energy sources are present in the biochemistry of AOB. We analyse how the predicted maximum growth yield of AOB changes considering co-metabolism, the use of hydroxylamine as a substrate, the abiotic oxidation of NO, energy harvesting in the monooxygenase enzyme or the use of organic carbon sources. (C) 2019 The Authors. Published by Elsevier Ltd.