Water Resources Division, U.S. Geological Survey, 430 National Center, Reston, Virginia 22092.
Appl Environ Microbiol. 1990 Jun;56(6):1858-64. doi: 10.1128/aem.56.6.1858-1864.1990.
The dissimilatory Fe(III) reducer, GS-15, is the first microorganism known to couple the oxidation of aromatic compounds to the reduction of Fe(III) and the first example of a pure culture of any kind known to anaerobically oxidize an aromatic hydrocarbon, toluene. In this study, the metabolism of toluene, phenol, and p-cresol by GS-15 was investigated in more detail. GS-15 grew in an anaerobic medium with toluene as the sole electron donor and Fe(III) oxide as the electron acceptor. Growth coincided with Fe(III) reduction. [ring-C]toluene was oxidized to CO(2), and the stoichiometry of CO(2) production and Fe(III) reduction indicated that GS-15 completely oxidized toluene to carbon dioxide with Fe(III) as the electron acceptor. Magnetite was the primary iron end product during toluene oxidation. Phenol and p-cresol were also completely oxidized to carbon dioxide with Fe(III) as the sole electron acceptor, and GS-15 could obtain energy to support growth by oxidizing either of these compounds as the sole electron donor. p-Hydroxybenzoate was a transitory extracellular intermediate of phenol and p-cresol metabolism but not of toluene metabolism. GS-15 oxidized potential aromatic intermediates in the oxidation of toluene (benzylalcohol and benzaldehyde) and p-cresol (p-hydroxybenzylalcohol and p-hydroxybenzaldehyde). The metabolism described here provides a model for how aromatic hydrocarbons and phenols may be oxidized with the reduction of Fe(III) in contaminated aquifers and petroleum-containing sediments.
异化三价铁还原菌 GS-15 是第一种已知能够将芳香族化合物的氧化与三价铁的还原偶联的微生物，也是第一种已知能够在无氧条件下氧化芳烃甲苯的纯培养物的例子。在本研究中，更详细地研究了 GS-15 对甲苯、苯酚和对甲酚的代谢。GS-15 在以甲苯为唯一电子供体和氧化铁为电子受体的厌氧培养基中生长。生长与三价铁还原同时发生。[环-C]甲苯被氧化为 CO2，CO2 生成和三价铁还原的化学计量表明 GS-15 完全将甲苯氧化为二氧化碳，三价铁作为电子受体。磁铁矿是甲苯氧化过程中的主要铁末端产物。苯酚和对甲酚也完全被氧化为二氧化碳，三价铁作为唯一的电子受体，GS-15 可以通过氧化这些化合物中的任何一种作为唯一的电子供体来获得支持生长的能量。对羟基苯甲酸是苯酚和对甲酚代谢过程中而不是甲苯代谢过程中的一种短暂的细胞外中间产物。GS-15 氧化甲苯（苯甲醇和苯甲醛）和对甲酚（对羟基苯甲醇和对羟基苯甲醛）氧化过程中的潜在芳香族中间产物。这里描述的代谢为芳烃和酚类化合物如何在受污染的含水层和含石油沉积物中与三价铁的还原一起氧化提供了一个模型。
