Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, PO Box 875001, Tempe, AZ 85287-5001, USA.
Appl Microbiol Biotechnol. 2011 Dec;92(5):1063-71. doi: 10.1007/s00253-011-3388-y. Epub 2011 Jun 12.
A novel anaerobic consortium, named DehaloR^2, that performs rapid and complete reductive dechlorination of trichloroethene (TCE) to ethene is described. DehaloR^2 was developed from estuarine sediment from the Back River of the Chesapeake Bay and has been stably maintained in the laboratory for over 2 years. Initial sediment microcosms showed incomplete reduction of TCE to DCE with a ratio of trans- to cis- isomers of 1.67. However, complete reduction to ethene was achieved within 10 days after transfer of the consortium to sediment-free media and was accompanied by a shift to cis-DCE as the prevailing intermediate metabolite. The microbial community shifted from dominance of the Proteobacterial phylum in the sediment to Firmicutes and Chloroflexi in DehaloR^2, containing the genera Acetobacterium, Clostridium, and the dechlorinators Dehalococcoides. Also present were Spirochaetes, possible acetogens, and Geobacter which encompass previously described dechlorinators. Rates of TCE to ethene reductive dechlorination reached 2.83 mM Cl- d(-1) in batch bottles with a Dehalococcoides sp. density of 1.54E+11 gene copies per liter, comparing favorably to other enrichment cultures described in the literature and identifying DehaloR^2 as a promising consortium for use in bioremediation of chlorinated ethene-impacted environments.
一种新型的厌氧群落，命名为 DehaloR^2，能够快速而完全地将三氯乙烯（TCE）还原为乙烯。DehaloR^2 是从切萨皮克湾的 Back 河的河口沉积物中分离出来的，已经在实验室中稳定维持了超过 2 年。最初的沉积物微宇宙显示 TCE 不完全还原为 DCE，反式异构体与顺式异构体的比例为 1.67。然而，在将群落转移到无沉积物的培养基后，10 天内即可实现完全还原为乙烯，并伴随着中间代谢产物 cis-DCE 的增加。微生物群落从沉积物中优势的 Proteobacteria 门转变为 DehaloR^2 中的 Firmicutes 和 Chloroflexi，其中包含 Acetobacterium、Clostridium 和脱氯菌 Dehalococcoides。还存在螺旋体，可能是产乙酸菌，以及囊括了先前描述的脱氯菌的 Geobacter。在批量瓶中，以每升 1.54E+11 个基因拷贝的 Dehalococcoides sp. 密度，TCE 还原为乙烯的脱氯速率达到 2.83 mM Cl- d(-1)，与文献中描述的其他富集培养物相比具有优势，表明 DehaloR^2 是一种很有前途的用于修复氯化乙烯污染环境的群落。
