Kleinsteuber Sabine, Schleinitz Kathleen M, Breitfeld Jana, Harms Hauke, Richnow Hans H, Vogt Carsten
Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany.
FEMS Microbiol Ecol. 2008 Oct;66(1):143-57. doi: 10.1111/j.1574-6941.2008.00536.x. Epub 2008 Jul 10.
The microbial communities of in situ reactor columns degrading benzene with sulfate as an electron acceptor were analyzed based on clone libraries and terminal restriction fragment length polymorphism fingerprinting of PCR-amplified 16S rRNA genes. The columns were filled with either lava granules or sand particles and percolated with groundwater from a benzene-contaminated aquifer. The predominant organisms colonizing the lava granules were related to Magnetobacterium sp., followed by a phylotype affiliated to the genera Cryptanaerobacter/Pelotomaculum and several Deltaproteobacteria. From the sand-filled columns, a stable benzene-degrading consortium was established in sand-filled laboratory microcosms under sulfate-reducing conditions. It was composed of Delta- and Epsilonproteobacteria, Clostridia, Chloroflexi, Actinobacteria and Bacteroidetes. The most prominent phylotype of the consortium was related to the genus Sulfurovum, followed by Desulfovibrio sp. and the Cryptanaerobacter/Pelotomaculum phylotype. The proportion of the latter was similar in both communities and significantly increased after repeated benzene-spiking. During cultivation on aromatic substrates other than benzene, the Cryptanaerobacter/Pelotomaculum phylotype was outcompeted by other community members. Hence, this organism appears to be specific for benzene as a growth substrate and might play a key role in benzene degradation in both communities. Based on the possible functions of the community members and thermodynamic calculations, a functional model for syntrophic benzene degradation under sulfate-reducing conditions is proposed.
基于克隆文库以及PCR扩增的16S rRNA基因的末端限制性片段长度多态性指纹图谱，对以硫酸盐作为电子受体降解苯的原位反应柱中的微生物群落进行了分析。反应柱填充有火山岩颗粒或沙粒，并用来自受苯污染含水层的地下水进行渗滤。定殖于火山岩颗粒上的主要微生物与嗜磁杆菌属相关，其次是属于隐厌氧杆菌属/泥杆菌属的一个系统发育型以及几种δ-变形菌。在装有沙子的反应柱中，在硫酸盐还原条件下于装有沙子的实验室微观环境中建立了一个稳定的苯降解菌群。它由δ-变形菌、ε-变形菌、梭菌纲、绿弯菌门、放线菌门和拟杆菌门组成。该菌群最突出的系统发育型与硫卵菌属相关，其次是脱硫弧菌属和隐厌氧杆菌属/泥杆菌属系统发育型。后者在两个群落中的比例相似，并且在重复加入苯后显著增加。在以苯以外的芳香族底物进行培养期间，隐厌氧杆菌属/泥杆菌属系统发育型被其他群落成员竞争淘汰。因此，这种微生物似乎对作为生长底物的苯具有特异性，并且可能在两个群落的苯降解中起关键作用。基于群落成员的可能功能以及热力学计算，提出了一个在硫酸盐还原条件下苯的互营降解功能模型。
