Anaerobic phenanthrene mineralization by a carboxylating sulfate-reducing bacterial enrichment
Anaerobic phenanthrene mineralization by a carboxylating sulfate-reducing bacterial enrichment
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DOI：
10.1038/ismej.2007.48
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发表时间：
2007-09-01
期刊：
影响因子：
11
通讯作者：
Suflita, Joseph M.
中科院分区：
文献类型：
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作者：
Davidova, Irene A.;Gieg, Lisa M.;Suflita, Joseph M.
关于高相对分子质量多环芳烃对厌氧生物降解的敏感性的信息相对较少。我们从碳氢化合物污染的海洋沉积物中获得了一株能够代谢菲的硫酸盐还原细菌。菲的降解与理论上预期的硫酸盐还原量符合化学计量比，并且被钼酸盐抑制。通过回收预期的(14)CO(2)量，证实了(14)C-菲的矿化作用。通过对质子化或氚代菲的稳定同位素研究，用气相色谱-质谱法检测到相应标记的菲羧酸。代谢物图谱与合成标准的比较证实，母体分子在C-2位发生了羧化。将(13)C-碳酸氢盐掺入羧基，意味着菲的直接羧化反应可能是关键的初始反应。变性梯度凝胶电泳法分析表明，克隆得到的两条主要条带和16S rRNA序列与已知的降解硫酸盐还原三角洲蛋白细菌聚在一起，表明它们可能参与了菲通过羧化的厌氧氧化反应。
Information on the susceptibility of higher molecular weight polynuclear aromatic hydrocarbons to anaerobic biodegradation is relatively rare. We obtained a sulfate-reducing bacterial enrichment capable of phenanthrene metabolism from a hydrocarbon-contaminated marine sediment. Phenanthrene degradation was in stoichiometric agreement with the theoretically expected amount of sulfate reduction and inhibited by molybdate. Mineralization of (14)C-phenanthrene by the enrichment was confirmed by the recovery of the expected amount of (14)CO(2). Stable isotope studies with protonated or deuterated phenanthrene resulted in the detection of the correspondingly labeled phenanthrene carboxylic acid by gas chromatography-mass spectrometry. Comparison of the metabolite profile with a synthesized standard confirmed that the parent molecule was carboxylated at the C-2 position. Incorporation of (13)C-bicarbonate into the carboxyl group implicated a direct carboxylation of phenanthrene as a likely key initial reaction. Denaturing gradient gel electrophoresis analysis of the enrichment showed only two major bands and 16S rRNA sequences obtained by cloning clustered with known hydrocarbon-degrading sulfate-reducing delta-proteobacteria, indicating their possible involvement in the anaerobic oxidation of phenanthrene via carboxylation as the initial activation reaction.