Anaerobic Cometabolic Transformation of Polycyclic and Heterocyclic Aromatic Hydrocarbons: Evidence from Laboratory and Field Studies
详细信息 查看全文
- 作者：Michael Safinowski ; Christian Griebler ; and Rainer U. Meckenstock
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：July 1, 2006
- 年：2006
- 卷：40
- 期：13
- 页码：4165 - 4173
- 全文大小：726K
- 年卷期：v.40,no.13(July 1, 2006)
- ISSN：1520-5851
文摘
The sulfate-reducing enrichment culture N47 can grow onnaphthalene or 2-methylnaphthalene as the sole carbonand energy source. Here we show that the culture canfurthermore cometabolically transform a variety of polycyclicand heteroaromatic compounds with naphthalene ormethylnaphthalene as the auxiliary substrate. Most of thecosubstrates were converted to the correspondingcarboxylic acids, frequently to several isomers. The massspectra of specific metabolites that were extractedfrom supernatants of cultures containing the cosubstratesbenzothiophene, benzofuran, and 1-methylnaphthaleneresembled known intermediates of the anaerobic naphthaleneand 2-methylnaphthalene degradation pathways (i.e.,naphthyl-2-methylsuccinic acid and naphthyl-2-methylenesuccinic acid). This indicates that some of the testedcompounds were first methylated and then transformed tothe corresponding methylsuccinic acids by a fumarateaddition to the methyl group. For some of the cosubstrates,a partial or total inhibition of growth on the auxiliarysubstrate was observed. This was not caused by the toxicityof the individual cosubstrate itself, but by a specificcombination of auxiliary substrate and cosubstrate. Noneof the cosubstrates tested could be utilized as the solecarbon source and electron donor by the enrichment cultureN47. Field investigations at the tar-oil-contaminatedaquifer, where strain N47 originated, revealed the presenceof a number of metabolites similar to the ones identifiedin batch culture supernatants. Our findings suggestthat aromatic hydrocarbons and heterocyclic compoundscan be converted by aquifer organisms and produce a varietyof polar compounds that become mobile in groundwater.