Department of Environmental Microbiology, Helmholtz Centre for Environmental Research--UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
Environ Microbiol. 2013 Sep;15(9):2603-15. doi: 10.1111/1462-2920.12168. Epub 2013 Jul 1.
Micro-organisms are known to degrade a wide range of toxic substances. How the environment shapes microbial communities in polluted ecosystems and thus influences degradation capabilities is not yet fully understood. In this study, we investigated microbial communities in a highly complex environment: the capillary fringe and subjacent sediments in a hydrocarbon-contaminated aquifer. Sixty sediment sections were analysed using terminal restriction fragment length polymorphism (T-RFLP) fingerprinting, cloning and sequencing of bacterial and archaeal 16S rRNA genes, complemented by chemical analyses of petroleum hydrocarbons, methane, oxygen and alternative terminal electron acceptors. Multivariate statistics revealed concentrations of contaminants and the position of the water table as significant factors shaping the microbial community composition. Micro-organisms with highest T-RFLP abundances were related to sulphate reducers belonging to the genus Desulfosporosinus, fermenting bacteria of the genera Sedimentibacter and Smithella, and aerobic hydrocarbon degraders of the genus Acidovorax. Furthermore, the acetoclastic methanogens Methanosaeta, and hydrogenotrophic methanogens Methanocella and Methanoregula were detected. Whereas sulphate and sulphate reducers prevail at the contamination source, the detection of methane, fermenting bacteria and methanogenic archaea further downstream points towards syntrophic hydrocarbon degradation.
微生物已知能降解多种有毒物质。然而，环境如何塑造受污染生态系统中的微生物群落，并因此影响降解能力，目前尚未完全了解。在这项研究中，我们调查了高度复杂环境中的微生物群落：受碳氢化合物污染的含水层中的毛细带和下方沉积物。使用末端限制性片段长度多态性（T-RFLP）指纹图谱、细菌和古菌 16S rRNA 基因的克隆和测序对 60 个沉积物样本进行了分析，辅之以对石油碳氢化合物、甲烷、氧气和替代末端电子受体的化学分析。多元统计分析显示，污染物浓度和地下水位位置是塑造微生物群落组成的重要因素。T-RFLP 丰度最高的微生物与硫酸盐还原菌属 Desulfosporosinus、Sedimentibacter 和 Smithella 属的发酵细菌以及属 Acidovorax 的好氧烃降解菌有关。此外，还检测到乙酸营养型产甲烷菌 Methanosaeta、氢营养型产甲烷菌 Methanocella 和 Methanoregula。硫酸盐和硫酸盐还原菌在污染源处占优势，而下游处检测到甲烷、发酵细菌和产甲烷古菌，则表明存在共营养型烃类降解。
