Kuhn E P, Zeyer J, Eicher P, Schwarzenbach R P
Swiss Federal Institute for Water Resources and Water Pollution Control, Kastanienbaum.
Appl Environ Microbiol. 1988 Feb;54(2):490-6. doi: 10.1128/aem.54.2.490-496.1988.
Toluene and m-xylene were rapidly mineralized in an anaerobic laboratory aquifer column operated under continuous-flow conditions with nitrate as an electron acceptor. The oxidation of toluene and m-xylene was coupled with the reduction of nitrate, and mineralization was confirmed by trapping 14CO2 evolved from 14C-ring-labeled substrates. Substrate degradation also took place when nitrous oxide replaced nitrate as an electron acceptor, but decomposition was inhibited in the presence of molecular oxygen or after the substitution of nitrate by nitrite. The m-xylene-adapted microorganisms in the aquifer column degraded toluene, benzaldehyde, benzoate, m-toluylaldehyde, m-toluate, m-cresol, p-cresol, and p-hydroxybenzoate but were unable to metabolize benzene, naphthalene, methylcyclohexane, and 1,3-dimethylcyclohexane. Isotope-dilution experiments suggested benzoate as an intermediate formed during anaerobic toluene metabolism. The finding that the highly water-soluble nitrous oxide served as electron acceptor for the anaerobic mineralization of some aromatic hydrocarbons may offer attractive options for the in situ restoration of polluted aquifers.
在以硝酸盐作为电子受体、连续流动条件下运行的厌氧实验室含水层柱中，甲苯和间二甲苯迅速被矿化。甲苯和间二甲苯的氧化与硝酸盐的还原相耦合，并且通过捕获从14C环标记底物释放出的14CO2证实了矿化作用。当一氧化二氮替代硝酸盐作为电子受体时，底物降解也会发生，但在有分子氧存在时或硝酸盐被亚硝酸盐替代后，分解作用受到抑制。含水层柱中适应间二甲苯的微生物能够降解甲苯、苯甲醛、苯甲酸盐、间甲苯甲醛、间甲苯酸盐、间甲酚、对甲酚和对羟基苯甲酸盐，但无法代谢苯、萘、甲基环己烷和1,3 - 二甲基环己烷。同位素稀释实验表明苯甲酸盐是厌氧甲苯代谢过程中形成的中间产物。高度水溶性的一氧化二氮作为某些芳香烃厌氧矿化的电子受体这一发现，可能为受污染含水层的原位修复提供有吸引力的选择。
