Molecular characterization of bacterial communities mineralizing benzene under sulfate-reducing conditions
Molecular characterization of bacterial communities mineralizing benzene under sulfate-reducing conditions
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DOI：
10.1111/j.1574-6941.2008.00536.x
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发表时间：
2008-10-01
影响因子：
4.2
通讯作者：
Vogt, Carsten
中科院分区：
文献类型：
--
作者：
Kleinsteuber, Sabine;Schleinitz, Kathleen M.;Vogt, Carsten
以16S rRNA基因的克隆文库和末端限制性片段长度多态性指纹图谱为基础，分析了以硫酸盐为电子受体的苯降解柱的微生物群落。这些柱子要么填满熔岩颗粒，要么填满沙粒，并用苯污染的含水层的地下水进行渗透。在熔岩颗粒中定植的优势微生物与磁杆菌属有关，其次是隐气杆菌/尖顶隐杆菌属和几种三角洲蛋白细菌。从填砂柱出发，在硫酸盐还原条件下，在填砂的实验室微观环境中建立了一个稳定的苯降解团。该菌主要由变形杆菌、梭状芽胞杆菌、绿假单胞菌、放线杆菌和类杆菌组成。该联盟最突出的系统类型与硫磺弧菌属有关，其次是硫磺弧菌属。和隐孢杆菌/杆状芽孢杆菌的系统型别。后者在两个群落中的比例相似，在反复加苯后显著增加。在苯以外的芳香族基质上培养时，隐气杆菌/杆状芽孢杆菌的系统型被其他群落成员击败。因此，这种微生物似乎是苯作为生长底物所特有的，并可能在两个群落中降解苯的过程中发挥关键作用。基于群落成员可能的功能和热力学计算，提出了硫酸盐还原条件下间苯降解的功能模型。
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.