Chloroethene degradation and expression of Dehalococcoides dehalogenase genes in cultures originating from Yangtze sediments
The anaerobic Dehalococcoides spp. is the only microorganism known to completely dechlorinate the hazardous compounds tetrachloroethene (PCE) or trichloroethene (TCE) via dichloroethene (DCE) and vinyl chloride (VC) to the terminal product, ethene. In this study, growth of Dehalococcoides spp. (DHC) and the expression of DHC dehalogenase genes were demonstrated for Yangtze enrichment cultures. Reductive dechlorination of chloroethenes occurred in Yangtze sediment without the addition of any external auxiliary substrates. All Yangtze enrichment cultures completely dechlorinated PCE and cis-DCE to ethene. To investigate expression of the dehalogenase genes pceA, tceA, vcrA, and bvcA, a protocol for messenger RNA (mRNA) extraction followed by reverse transcription and quantitative PCR analysis was established. During dechlorination, an increase in gene copy numbers of pceA, tceA, and vcrA was observed. However, temporary formation of mRNA was only measured in the case of the dehalogenase genes tceA and vcrA. Comparison of DHC dehalogenase patterns indicated that the Yangtze DHC community does not match any of the previously published enrichment cultures that were obtained from contaminated areas in the USA or Europe.
KeywordsChloroethenes Dehalococcoides Dehalogenases Yangtze River sediments mRNA Reductive dechlorination
The authors gratefully acknowledge financial support from the German Ministry of Education and Research (BMBF, Grant No. 02WT1130). This study is part of the Sino-German Yangtze-Hydro-Project (www.yangtze-project.de). Eva Lüthen is also acknowledged for preparing the sediment microcosm experiments, and Prof. Chaofeng Shen for translation of Chinese publications.
- Bælum J, Chambon JC, Scheutz C, Binning PJ, Laier T, Bjerg PL, Jacobsen CS (2013) A conceptual model linking functional gene expression and reductive dechlorination rates of chlorinated ethenes in clay rich groundwater sediment. Water Res 47:2467–2478. doi: 10.1016/j.watres.2013.02.016 CrossRefGoogle Scholar
- Behrens S, Azizian MF, McMurdie PJ, Sabalowsky A, Dolan ME, Semprini L, Spormann AM (2008) Monitoring abundance and expression of “Dehalococcoides” species chloroethene-reductive dehalogenases in a tetrachloroethene-dechlorinating flow column. Appl Environ Microbiol 74:5695–5703. doi: 10.1128/AEM.00926-08 CrossRefGoogle Scholar
- Han FA, Chen J, Jiang ZF (2011) Investigation of VOCs and SVOCs in surface water source in Jiangsu, Zhejiang, Shandong Province, China. J Environ Health 28:890–894 (in Chinese)Google Scholar
- Johnson DR, Lee PKH, Holmes VF, Alvarez-Cohen L (2005) An internal reference technique for accurately quantifying specific mRNAs by real-time PCR with application to the tceA reductive dehalogenase gene. Appl Environ Microbiol 71:3866–3871. doi: 10.1128/AEM.71.7.3866-3871.2005 CrossRefGoogle Scholar
- Kranzioch I, Stoll C, Holbach A, Chen H, Wang L, Zheng B, Norra S, Bi Y, Schramm K-W, Tiehm A (2013) Dechlorination and organohalide-respiring bacteria dynamics in sediment samples of the Yangtze Three Gorges Reservoir. Environ Sci Pollut R 20:7046–7056. doi: 10.1007/s11356-013-1545-9 CrossRefGoogle Scholar
- Lee PKH, Johnson DR, Holmes VF, He J, Alvarez-Cohen L (2006) Reductive dehalogenase gene expression as a biomarker for physiological activity of Dehalococcoides spp. Appl Environ Microb 72(9):6161–6168. doi: 10.1128/AEM.01070-06
- Lee PKH, Cheng D, West KA, Alvarez-Cohen L, He J (2013) Isolation of two new Dehalococcoides mccartyi strains with dissimilar dechlorination functions and their characterization by comparative genomics via microarray analysis. Environ Microbiol 15:2293–2305. doi: 10.1111/1462-2920.12099 CrossRefGoogle Scholar
- Li B, Chen H, Cao X (2006) Chlorinated hydrocarbons and BTEX in Yangtze River Delta region shallow groundwater, China. http://en.cgs.gov.cn/Achievement/The34thCongress/Recovery/18687.htm. Accessed 02 October 2013
- Löffler FE, Yan J, Ritalahti KM, Adrian L, Edwards EA, Konstantinidis KT, Müller JA, Fullerton H, Zinder SH, Spormann AM (2013) Dehalococcoides mccartyi gen. nov., sp. nov., obligately organohalide–respiring anaerobic bacteria relevant to halogen cycling and bioremediation, belong to a novel bacterial class, Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov., within the phylum Chloroflexi. Int J Syst Evol Microbiol 63:625–635. doi: 10.1099/ijs.0.034926-0 CrossRefGoogle Scholar
- Magnuson JK, Stern RV, Gossett JM, Zinder SH, Burris DR (1998) Reductive dechlorination of tetrachloroethene to ethene by a two-component enzyme pathway. Appl Environ Microbiol 64:1270–1275Google Scholar
- Müller JA, Rosner BM, von Abendroth G, Meshulam-Simon G, McCarty PL, Spormann AM (2004) Molecular identification of the catabolic vinyl chloride reductase from Dehalococcoides sp. strain VS and its environmental distribution. Appl Environ Microbiol 70:4880–4888. doi: 10.1128/AEM.70.8.4880-4888.2004 CrossRefGoogle Scholar
- Pöritz M, Goris T, Wubet T, Tarkka MT, Buscot F, Nijenhuis I, Lechner U, Adrian L (2013) Genome sequences of two dehalogenation specialists – Dehalococcoides mccartyi strains BTF08 and DCMB5 enriched from the highly polluted Bitterfeld region. FEMS Microbiol Lett 343:101–104. doi: 10.1111/1574-6968.12160 CrossRefGoogle Scholar