Villemur Richard, Lanthier Martin, Beaudet Réjean, Lépine François
INRS-Institut Armand-Frappier, Laval, Québec, Canada.
FEMS Microbiol Rev. 2006 Sep;30(5):706-33. doi: 10.1111/j.1574-6976.2006.00029.x.
Desulfitobacterium spp. are strictly anaerobic bacteria that were first isolated from environments contaminated by halogenated organic compounds. They are very versatile microorganisms that can use a wide variety of electron acceptors, such as nitrate, sulfite, metals, humic acids, and man-made or naturally occurring halogenated organic compounds. Most of the Desulfitobacterium strains can dehalogenate halogenated organic compounds by mechanisms of reductive dehalogenation, although the substrate spectrum of halogenated organic compounds varies substantially from one strain to another, even with strains belonging to the same species. A number of reductive dehalogenases and their corresponding gene loci have been isolated from these strains. Some of these loci are flanked by transposition sequences, suggesting that they can be transmitted by horizontal transfer via a catabolic transposon. Desulfitobacterium spp. can use H2 as electron donor below the threshold concentration that would allow sulfate reduction and methanogenesis. Furthermore, there is some evidence that syntrophic relationships occur between Desulfitobacterium spp. and sulfate-reducing bacteria, from which the Desulfitobacterium cells acquire their electrons by interspecies hydrogen transfer, and it is believed that this relationship also occurs in a methanogenic consortium. Because of their versatility, desulfitobacteria can be excellent candidates for the development of anaerobic bioremediation processes. The release of the complete genome of Desulfitobacterium hafniense strain Y51 and information from the partial genome sequence of D. hafniense strain DCB-2 will certainly help in predicting how desulfitobacteria interact with their environments and other microorganisms, and the mechanisms of actions related to reductive dehalogenation.
脱卤脱硫杆菌属是严格厌氧细菌，最初是从受卤代有机化合物污染的环境中分离出来的。它们是非常多样化的微生物，能够利用多种电子受体，如硝酸盐、亚硫酸盐、金属、腐殖酸以及人造或天然存在的卤代有机化合物。大多数脱卤脱硫杆菌菌株可通过还原脱卤机制使卤代有机化合物脱卤，不过卤代有机化合物的底物谱在不同菌株间差异很大，即使是属于同一物种的菌株也是如此。已从这些菌株中分离出许多还原脱卤酶及其相应的基因位点。其中一些位点两侧有转座序列，这表明它们可通过分解代谢转座子进行水平转移。在低于允许硫酸盐还原和产甲烷的阈值浓度下，脱卤脱硫杆菌属可以利用氢气作为电子供体。此外，有证据表明脱卤脱硫杆菌属与硫酸盐还原菌之间存在互营关系，脱卤脱硫杆菌细胞通过种间氢转移获取电子，并且据信这种关系也存在于产甲烷菌群中。由于其多样性，脱卤脱硫杆菌可成为开发厌氧生物修复过程的理想候选者。嗜温脱卤脱硫杆菌菌株Y51完整基因组的公布以及嗜温脱卤脱硫杆菌菌株DCB - 2部分基因组序列的信息，肯定有助于预测脱卤脱硫杆菌如何与它们的环境及其他微生物相互作用，以及与还原脱卤相关的作用机制。
