Analysis of methanotrophic bacteria in Movile Cave by stable isotope probing

Wiley - Tập 6 Số 2 - Trang 111-120 - 2004
Elena Hutchens1, Stefan Radajewski2, Marc G. Dumont2, Ian R. McDonald2, J. Colin Murrell2
1Babes‐Bolyai University, Department of Plant Biology, Kogalniceanu 1, 3400 Cluj, Romania.
2University of Warwick, Department of Biological Sciences, Coventry CV4 7AL, UK

Tóm tắt

SummaryMovile Cave is an unusual groundwater ecosystem that is supported by in situ chemoautotrophic production. The cave atmosphere contains 1–2% methane (CH4), although much higher concentrations are found in gas bubbles that keep microbial mats afloat on the water surface. As previous analyses of stable carbon isotope ratios have suggested that methane oxidation occurs in this environment, we hypothesized that aerobic methane‐oxidizing bacteria (methanotrophs) are active in Movile Cave. To identify the active methanotrophs in the water and mat material from Movile Cave, a microcosm was incubated with a 10%13CH4 headspace in a DNA‐based stable isotope probing (DNA‐SIP) experiment. Using improved centrifugation conditions, a 13C‐labelled DNA fraction was collected and used as a template for polymerase chain reaction amplification. Analysis of genes encoding the small‐subunit rRNA and key enzymes in the methane oxidation pathway of methanotrophs identified that strains of Methylomonas, Methylococcus and Methylocystis/Methylosinus had assimilated the 13CH4, and that these methanotrophs contain genes encoding both known types of methane monooxygenase (MMO). Sequences of non‐methanotrophic bacteria and an alga provided evidence for turnover of CH4 due to possible cross‐feeding on 13C‐labelled metabolites or biomass. Our results suggest that aerobic methanotrophs actively convert CH4 into complex organic compounds in Movile Cave and thus help to sustain a diverse community of microorganisms in this closed ecosystem.

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Tài liệu tham khảo

10.1016/S0022-2836(05)80360-2

10.1046/j.1462-2920.2002.00323.x

10.1128/AEM.66.12.5259-5266.2000

10.1046/j.1462-2920.2003.00450.x

10.1128/AEM.67.9.3802-3809.2001

10.1128/AEM.65.11.5066-5074.1999

10.1046/j.1462-2920.2002.00318.x

10.1099/00207713-50-3-955

10.1111/j.1574-6941.2003.tb01070.x

10.1073/pnas.89.12.5685

10.1111/j.1574-6941.2002.tb00962.x

10.1128/AEM.65.11.4863-4872.1999

10.1128/AEM.65.5.1980-1990.1999

10.1099/00221287-148-9-2831

10.1111/j.1574-6968.1995.tb07834.x

10.1099/13500872-141-8-1947

10.1007/s00248-007-9320-4

Lidstrom M.E., 2001, The Prokaryotes

10.1002/elps.1150190416

10.1128/AEM.63.8.3218-3224.1997

10.1111/j.1574-6968.1997.tb12728.x

10.1128/AEM.68.3.1446-1453.2002

Murrell J.C., 2000, Cultivation‐independent techniques for studying methanotroph ecology, Res Microbiol, 151, 1

10.1016/S0966-842X(00)01739-X

10.1111/j.1462-2920.2006.01018.x

10.1099/00221287-148-8-2331

10.1016/S0958-1669(03)00064-8

10.1002/abio.200390000

Sarbu S.M., 1995, A subterranean chemoautotrophically based ecosystem, NSS Bull, 57, 91

10.1080/01490459409377984

10.1007/978-3-642-78991-5_4

10.1126/science.272.5270.1953

10.1128/AEM.62.4.1265-1273.1996

Shigematsu T., 1999, Soluble methane monooxygenase gene clusters from trichloroethylene‐degrading Methylomonas sp. strains and detection of methanotrophs during in situ bioremediation, Appl Environ Microbiol, 65, 5198, 10.1128/AEM.65.12.5198-5206.1999

10.1099/00221287-148-11-3617

10.1128/AEM.63.8.3123-3127.1997

10.1111/j.1574-6976.1997.tb00351.x