School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States.
Curr Opin Biotechnol. 2013 Jun;24(3):498-505. doi: 10.1016/j.copbio.2013.02.014. Epub 2013 Mar 13.
In the last few years there has been a burst of genomes released for organohalide respiring bacteria (referred to as OHRB herein though the process is otherwise known as dehalorespiration, reductive dechlorination, or halorespiration). The microorganisms are employed in bioremediation of sites contaminated with chlorinated ethene, ethane, and methanes, as well as chlorinated aromatics. Of particular note are the releases of the first Dehalogenimonas genome (a Dehalococcoides-related Chloroflexi) and not one but seven Dehalobacter (meta)genomes. Collectively, genomes from these three genera (Dehalococcoides, Dehalogenimonas, and Dehalobacter) clearly support their niche as obligate OHRB, while other genera with sequenced genomes (Desulfitobacterium, Geobacter, and Anaeromyxobacter) maintain organohalide respiration (OHR) as one of many possible energy conserving respiration strategies. The obligate OHRB genomes consistently harbor 10-39 unique reductive dehalogenase (RDase) genes and they are flanked with not only transcriptional regulators but also transposition related genes. Active transposition likely plays a key role in the accumulation of such a broad and tightly regulated dehalogenase repertoire. Functional assays are now the bottleneck for genome-informed discovery of dehalogenase substrate ranges.
在过去的几年中，已经有大量的有机卤化物呼吸细菌（以下简称 OHRB，尽管该过程也被称为脱卤呼吸、还原脱氯或卤呼吸）的基因组被发布。这些微生物被用于修复受氯代乙烯、乙烷和甲烷以及氯代芳烃污染的场地。特别值得注意的是，第一个 Dehalogenimonas 基因组（与 Dehalococcoides 相关的 Chloroflexi）以及七个 Dehalobacter（变形菌门）基因组的发布。这三个属（Dehalococcoides、Dehalogenimonas 和 Dehalobacter）的基因组共同支持了它们作为严格的 OHRB 的生态位，而其他具有测序基因组的属（脱硫菌属、地杆菌属和厌氧粘细菌属）则将有机卤化物呼吸（OHR）作为许多可能的能量保存呼吸策略之一保留下来。严格的 OHRB 基因组通常含有 10-39 种独特的还原脱卤酶（RDase）基因，这些基因不仅被转录调节剂包围，还被转座相关基因包围。活跃的转座可能在积累如此广泛和严格调控的脱卤酶库方面发挥了关键作用。功能测定现在是基于基因组信息发现脱卤酶底物范围的瓶颈。
