Publication:

The quantitative significance of Syntrophaceae and syntrophic partnerships in methanogenic degradation of crude oil alkanes (2011)

Author(s): Gray ND, Sherry A, Grant RJ, Rowan AK, Hubert CRJ, Callbeck CM, Aitken CM, Jones DM, Adams JJ, Larter SR, Head IM

    Abstract: Libraries of 16S rRNA genes cloned from methanogenic oil degrading microcosms amended with North Sea crude oil and inoculated with estuarine sediment indicated that bacteria from the genera Smithella (Deltaproteobacteria, Syntrophaceace) and Marinobacter sp. (Gammaproteobacteria) were enriched during degradation. Growth yields and doubling times (36 days for both Smithella and Marinobacter) were determined using qPCR and quantitative data on alkanes, which were the predominant hydrocarbons degraded. The growth yield of the Smithella sp. [0.020 g(cell-C)/g(alkane-C)], assuming it utilized all alkanes removed was consistent with yields of bacteria that degrade hydrocarbons and other organic compounds in methanogenic consortia. Over 450 days of incubation predominance and exponential growth of Smithella was coincident with alkane removal and exponential accumulation of methane. This growth is consistent with Smithella's occurrence in near surface anoxic hydrocarbon degrading systems and their complete oxidation of crude oil alkanes to acetate and/or hydrogen in syntrophic partnership with methanogens in such systems. The calculated growth yield of the Marinobacter sp., assuming it grew on alkanes, was [0.0005 g(cell-C)/g(alkane-C)] suggesting that it played a minor role in alkane degradation. The dominant methanogens were hydrogenotrophs (Methanocalculus spp. from the Methanomicrobiales). Enrichment of hydrogen-oxidizing methanogens relative to acetoclastic methanogens was consistent with syntrophic acetate oxidation measured in methanogenic crude oil degrading enrichment cultures. qPCR of the Methanomicrobiales indicated growth characteristics consistent with measured rates of methane production and growth in partnership with Smithella.

      • Date: 14-09-2011
      • Journal: Environmental Microbiology
      • Volume: 13
      • Issue: 11
      • Pages: 2957-2975
      • Publisher: Wiley-Blackwell Publishing Ltd.
      • Publication type: Article
      • Bibliographic status: Published
      Staff

      Dr Carolyn Aitken
      Research Associate

      Dr Neil Gray
      Reader in Geomicrobiology and RCUK Research Fellow

      Professor Ian Head
      Prof of Environmental Microbiology

      Dr Casey Hubert
      Reader in Geomicrobiology & EPSRC Research Fellow

      Dr Martin Jones
      Analytical Facilities Manager

      Professor Stephen Larter
      Fellow of the Royal Society

      Dr Angela Sherry
      School and SAgE Faculty Research Fellow (Geomicrobiology)