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Research Associate in Microbial Biogeochemistry

My postdoctoral research focuses on understanding the processes and microorganisms (particularly methanogenic Archaea) involved in methane production in the upper oceans.  This involves using DNA based analysis and biogeochemical gas measurements. 

In broader terms my research interests include understanding how microbial communities cycle carbon, nitrogen and sulphur in both natural and engineered environments.

At the Scottish Marine Institute I am a member of the ...

and a user of the analytical capabilities and research vessels of the Institute.

 

Career / education

 

Research

Research projects

Unravelling the Oceanic Methane Paradox

The world’s upper oceans are typically supersaturated with dissolved methane, thought to result from in situ microbial methane production.  This observed supersaturation has been termed the 'oceanic methane paradox' because the microorganisms (methanogenic Archaea) primarily responsible for methane production (methanogensis) can not tolerate oxygen and the upper oceans are highly oxygenated.  Recent evidence has suggested that anaerobic (without oxygen) microsites within marine zooplankton (small animals), their excreted faecal pellets and sedimentary material may provide a suitable habitat for methanogens and could hence be sites for methane production in the upper ocean.

Methanogenic Archaea have been identified in faecal pellets and sedimentary material (work at SAMS).  This has lead to an insight into the pathways involved in methane production in the upper ocean.  Different groups of methanogens can utilize different substrates (carbon dioxide, acetate and methylated substrates).  The methanogens identified at SAMS are known for their unique ability to utilize methylated substrates.  One group of methylated compounds that may represent substrates for methanogens in the upper oceans is the algal derived compounds consumed by zooplankton, dimethylsulphide (DMS) and the methylamines (MA).  DMS and MA are climatic feedback gases thus this work has important consequences for our understanding of the role the oceans and oceanic gases play in climate change.

 

ICE CHASER expedition to the Arctic 2008

My primary role on the Arctic cruise was to investigate the processes and microorganisms involved in methane production in the pelagic/ice environment of the Arctic.  This involved collecting and preserving sedimentary material (surface sediment and sedimentary particles in upper oceans), water samples, ice cores and copepods and their faecal pellets for microbial analysis.  Further to this, anaerobic ice core microcosm experiments were set up to investigate methane production under different conditions.  Samples were also collected for analysis of biogenic sulphur compounds (dimethlysulphoniopropionate-DMSP/dimethylsulfoxide-DMSO).

Publications

My publications

  • Aitken, C.M., Jones, D.M., Gray, N.D., Sherry, A., Bowler, B.F.L, Rowan, A.K., Larter, S.R. and Head, I.M. Crude oil alkane activation under sulfate-reducing & methanogenic conditions proceeds by different mechnisms. Submitted to Geochimica et Cosmochimica Acta.

  • Oldenburg, T.B.P, Larter S.R., Adams J.J., Rowan A.K., Brown A., Head I.M., Grigoriyan, A.A., Voordouw G., Fustic M. and Hubert C. 2009 Methods for recovery of microorganisms and intact polar lipids (IPLs) from oil-water mixtures lab experiments and natural well-head fluids. Analytical Chemistry, 81(10), 4130-4136.

  • Head, I.M., Larter, S.R., Gray, N.D., Brown, A. , Adams, J.J., Aitken, C.M., Jones, D.M., Rowan, A.K., Huang, H., Röling, W.F.M. Hydrocarbon Degradation in Petroleum Reservoirs. . In: Timmis, K.N, ed. Microbiology of Hydrocarbons, Oils, Lipids. Heidelberg, Germany: Springer, 2009

  • *D.M. Jones, I. M. Head, N. D. Gray, J.J. Adams, A. K. Rowan, C.M. Aitken, B. Bennett, H. Huang, A. Brown, B.F.J. Bowler, and S.R. Larter.  2008. Crude oil biodegradation via methanogenesis in subsurface petroleum reservoirs. Nature, 451, 176-180.  *Organic Geochemistry Division Best Paper Award for 2008

  • Gray, N.D., Brown, A, Nelson, D.R., Pickup, R.W., Rowan, A.K. and I.M. Head. 2007 The biogeographical distrubution of closely related freshwater sediment bacteria is determined by environmental selection. The ISME Journal. 1(7):596-606

  • Demspsey, M.J., Porto, I., Mustafa, M., Rowan A.K., Brown, A., and I.M. Head.  2006. The expanded bed biofilter: combined nitrification, solids destruction, and removal of bacteria.  Water Science and Technology.  54(8): 37-46.    

  • Rowan, A.K., Snape, J.R., Fearnside, D., Curtis, T.P., Barer, M.R. and I.M. Head. 2005. Development of a rapid assay for quantification of ammonia-oxidising bacteria in wastewater treatment plants. Applied and Environmental Microbiology. 71: 8481-8490.

  • Rowan, A.K., Snape, J.R., Fearnside, D., Curtis, T.P., Barer, M.R. and I.M. Head.  2005. Changes in AOB community structure in full-scale wastewater treatment reactors following a change in wastewater composition.  In: Proceedings of the Third Chartered Institute for Water and Environmental Management National Conference 2005.  Not peer reviewed

  • Rowan, A.K., Snape, J.R., Fearnside, D., Curtis, T.P., Barer, M.R. and I.M. Head. 2003. Composition and diversity of ammonia-oxidising bacterial communities in wastewater treatment reactors of different design treating identical wastewater. FEMS Microbiology Ecology. 43:195-206.

  • Rowan, A.K., Moser, G., Gray, N., Snape, J.R., Fearnside, D., Curtis, T.P., Barer, M.R. and I.M. Head. 2003. A comparative study of ammonia-oxidising bacteria in lab-scale industrial wastewater treatment reactors. Water Science and Technology. 48(3): 17-24.

  • Rowan, A.K., Snape, J.R., Fearnside, D., Curtis, T.P., Barer, M.R. and I.M. Head. 2002. A comparison of autotrophic ammonia-oxidising bacteria in full-and laboratory-scale wastewater treatment reactors. Water Science and Technology. 46(1-2): 319-322.

  • Gray, N.D., Howarth, R., Rowan, A., Pickup, R.W., Jones, J.G. and Head, I.M. 1999. Natural communities of Achromatium oxaliferum comprise genetically, morphologically and ecologically distinct sub-populations. Applied and Environmental Microbiology. 65 (11), 5089-5099

 

External

external activities / measures of esteem
  • Research outputs include 9 peer reviewed papers and 1 in submission process
  • Chairperson at Molecular Microbial Ecology Group (MMEG) 14 & 15 (2008; 2009)
  • Presentation at both national and international level (11 oral, 9 poster; 1999-2010)
  • Selected to present a poster of my research at Westminster (Annual reception for Britain’s young scientists, engineers and technologists, 2006) 
  • Selected from participants of UK water conference to present at international conference

 

Outreach activities

  • Active STEM ambassador (promoting science to young people- www.stemnet.org.uk)
  • Involvement in Sharing Science event at Our Dynamic Earth (public engagement event showcasing Arctic research), March 2009.  The hands on display also formed part of polar oceans activities for 2009 (International Polar Year 07-08)
  • Invited speaker: Oban and Lorn Environment Week 2008 (series of public lectures about exciting environmental research coordinated by the Argyll and Bute Regional Environmental Education Forum (ABREEF)),
  • Speaker at local primary schools (Rockfield, Oban & Achaleven, Connel) & Lochaber's University of the 3rd Age group. Title: What do polar bears eat?
  • Involvement in open days (2008, 2009, 2010), local science fun days (2007) & SAMS Festival of the Sea
  • Participation in Ocean Science on Tall Ship initiative: collaboration between the Future Ship project, the jubilee sailing trust (charity that enables participants whatever their physical ability to challenge themselves through the adventure of tall ship sailing) and the Challenger society and aimed to conduct marine research on a low carbon footprint tall ship, and integrate and educate the non-scientists onboard and promote marine science to the general public.  

Teaching

teaching activities

BSc (Hons) Marine Science programme

  • Lectures, tutorials and practical classes: Marine Biogeochemical Cycling (year 3)
 
My contact details

Dr Arlene Rowan SAMS

Dr Arlene Ditchfield

E: arlene.ditchfield@sams.ac.uk

T: +44 (0)1631 559 429

F: +44 (0)1631 559 001

Scottish Marine Institute

Oban, Argyll PA37 1QA, UK

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