Denise M Akob, Ph.D.


Dr. Denise M. Akob is a geomicrobiologist whose research focuses on understanding how microorganisms impact their environment and biogeochemical cycles and in turn, how an environment impacts microorganisms. She investigates both contaminated and pristine environments. Her research focuses primarily on understanding microbial impacts on Cold War Biogeochemistry (uranium and chlorinated solvent contamination) and energy production (either by mitigating degradation of contaminants (from hydraulic fracturing or oil spills) or by enhancing natural gas production)). 

Dr. Akob received her undergraduate degree in Biology from St. Mary’s College of Maryland.  She completed her PhD in Biogeochemical Oceanography from Florida State University in 2008 and was a post-doctoral research fellow at Friedrich Schiller University Jena, Germany from 2008-2012. Dr. Akob joined the U.S. Geological Survey in 2012 and is a research scientist in the Water Mission Area's Earth System Processes Division Water Cycle Branch. For more information please visit the Reston Microbiology Lab website.


  • Ph.D. 2008, Florida State University, Department of Oceanography, Advisor: Dr. Joel E. Kostka
  • B.A. 2002, St. Mary’s College of Maryland, Major: Biology

Professional Experience

  • Adjunct Graduate Faculty, University of Alabama, Department of Biological Sciences, 2016-present.
  • Associate Editor, Biogeosciences, 2016-present.
  • Affiliated Professor, Department of Geography and Planning, Appalachian State University, 2016-current.
  • Editorial Board Member, FEMS Microbiology Ecology, 2016-present.
  • Affiliated Professor, Environmental Science and Policy Department at George Mason University, 2013-current.
  • Research Microbiologist, U.S. Geological Survey, National Research Program (Water), Reston Microbiology Laboratory. 2012-current
  • Postdoctoral Research Fellow, Friedrich-Schiller University Jena, Institute of Ecology, Aquatic Geomicrobiology. 2010-2012
  • Marie Curie Postdoctoral Research Fellow, Friedrich-Schiller University Jena, Institute of Ecology, Aquatic Geomicrobiology. 2008-2010


  1. Cozzarelli, I. M., D. M. Akob, M. J. Baedecker, T. Spencer, J. Jaeschke, D. S. Dunlap, A. C. Mumford, A. T. Poret-Peterson, D. B. Chambers. 2017. Degradation of MCHM (4-methylcyclohexanemethanol) in Sediments from Elk River, West Virginia. Environmental Science and Technology, in press [Link]

  2. Akob, D. M., S. M. Baesman, J. M. Sutton, J. L. Fierst, A. C. Mumford, Y. Shrestha, A. T. Poret-Peterson, S. Bennett, D. S. Dunlap, K. B. Haase, R. S. Oremland. 2017. Detection of Diazotrophy in the Acetylene-Fermenting Anaerobe, Pelobacter strain SFB93. Applied and Environmental Microbiology, 83(17): e01198-17,
  3. Lazar, C.S., W. Stoll, R. Lehmann, M. Herrmann, V. Schwab, D. M. Akob, A. Nawaz, T. Wubet, F. Buscot, K.-U. Totsche, and K. Küsel. Archaea in carbonate-rock groundwater ecosystems differ with regard to autotrophy vs. heterotrophy. Archaea, 2017: 1-13,
  4. Orem, W., M. Varonka, L. Crosby, K. Haase, K. Loftin, M. Hladik, D. M. Akob, C. Tatu, A. Mumford, J. Jaeschke, A. Bates, T. Schell, and I.M. Cozzarelli. Organic Geochemistry and Toxicology of a Stream Impacted by Unconventional Oil and Gas Wastewater Disposal Operations. Applied Geochemistry, 80: 155-167,
  5. Fahrenfeld, N.L., H. Delos Reyes, A. Eramo, D. M. Akob, I.M. Cozzarelli, and A. Mumford. 2017. Shifts in microbial community structure and function in surface waters impacted by unconventional oil and gas wastewaters revealed by metagenomics, Science of the Total Environment, 580: 1205–1213,
  6. Sutton, J. M., S. M. Baesman, J. L. Fierst, A. T. Poret-Peterson, R. S. Oremland, D. S. Dunlap, and D. M. Akob. 2017. Complete Genome Sequences of two Acetylene Fermenting Pelobacter acetylenicus Strains. Genome Announcements, 5:e01572-16,
  7. Sutton, J. M., S. M. Baesman, J. L. Fierst, A. T. Poret-Peterson, R. S. Oremland, D. S. Dunlap, and D. M. Akob. 2017. Complete Genome Sequence of the Acetylene Fermenting Pelobacter strain SFB93. Genome Announcements, 5:e01573-16,
  8. Cozzarelli, I. M., K.J. Skalak, D. B. Kent, M.A. Engle, A. Benthem, A.C. Mumford, K. Haase, A. Farag, D. Harper, S. C. Nagel, L.R. Iwanowicz, W. H. Orem, D. M. Akob, J. B. Jaeschke, J. Galloway, M. Kohler, D. L. Stoliker, G. Jolly. 2017. Environmental Signatures and Effects of a Spill of Untreated Oil and Gas Wastewater in the Williston Basin, North Dakota. Science of the Total Environment, 579: 1782-1795,
  9. Ouyang, B., D. M. Akob, D. S. Dunlap, and D. Renock. 2017. Microbially mediated barite dissolution in anoxic brines. Applied Geochemistry, 76: 51-59,
  10. Shelton, J. L., D. M. Akob, J. C. McIntosh, N. Fierer, J. R. Spear, P. D. Warwick, J. E. McCray. 2016. Environmental Drivers of Differences in Microbial Community Structure in Crude Oil Reservoirs across a Methanogenic Gradient. Frontiers in Microbiology, 7(1535),
  11. Akob, D.M., A. Mumford, W. H. Orem, M. Engle, J.G. Klinges, D. B. Kent and I. M. Cozzarelli. 2016. Wastewater Disposal from Unconventional Oil and Gas Development Degrades Stream Quality at a West Virginia Injection Facility. Environmental Science and Technology, 50 (11): 5517–5525,
  12. Kassotis, C.D., L.R. Iwanowicz, D.M. Akob, I.M. Cozzarelli, A.C. Mumford, W.H. Orem, and S.C. Nagel. 2016. Endocrine Disrupting Activities of Surface Water Associated with a West Virginia Oil and Gas Industry Wastewater Disposal Site. Science of the Total Environment, 557–558: 901–910,
  13. Akob, D. M., Sumy, D., Hermes, J., and Horsfall, F. 2016. CAREER PROFILES: Options and Insights. Oceanography 29(1): 106-110.
  14. Bohu, T., D.M. Akob, M. Abratis, C.S. Lazar, and K. Küsel. 2016. Biological low pH Mn(II) oxidation in a manganese deposit influenced by acidic heavy metal-rich groundwater. Applied and Environmental Microbiology, 82 (10): 3009 –3021,
  15. Fabisch, M., G. Freyer, C. A. Johnson, G. Büchel, D. M. Akob, T. R. Neu, and K. Küsel. 2016. Dominance of ‘Gallionella capsiferriformans’ and heavy metal association with Gallionella-like stalks in metal-rich pH 6 mine water discharge. Geobiology, 14: 68–90,
  16. Bohu, T. , C. Santelli, D. M. Akob, T. R. Neu, V. Ciobota, P. Rösch, J. Popp, S. Nietzsche, and K. Küsel. 2015. Characterization of pH dependent Mn(II) oxidation strategies and acidic pH bixbyite formation by Mesorhizobium australicum T-G1. Frontiers in Microbiology, 6: e734,
  17. Akob, D. M., I. M. Cozzarelli, D. S. Dunlap, E. L. Rowan and M. M. Lorah. 2015. Organic and Inorganic Composition and Microbiology of Produced Waters from Pennsylvania Shale Gas Wells. Applied Geochemistry, 60:116-125,
  18. Ritter, D., D. Vinson, E. Barnhart, D. M. Akob, M. Fields, A. Cunningham, W. Orem, J. C. McIntosh. 2015. Enhanced Microbial Coalbed Methane Generation: A Review of Potential and Limitations. International Journal of Coal Geology, 146: 28–41, DOI:10.1016/j.coal.2015.04.013.
  19. Herrmann. M., A. Rusznyák, D. M. Akob, I. Schulze*, S. Opitz*, K.-U. Totsche, and K. Küsel. 2015. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds. Applied and Environmental Microbiology, 81(7): 2384-2394.
  20. Beulig, F., V. B. Heuer, D. M. Akob, B. Viehweger, M. Elvert, M. Herrmann, K.-U. Hinrichs, and K. Küsel. 2015. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette. The ISME Journal 9(3): 746-59.
  21. Akob, D. M., T. Bo Hu, A. Beyer, F. Schäffner, M. Händel, D. Merten, G. Büchel, K.-U. Totsche, and K. Küsel. 2014. Identification of Mn(II)-oxidizing bacteria from a low pH contaminated former uranium mine. Applied and Environmental Microbiology, 80(16): 5086-5097.
  22. Fabisch, M., F. Beulig, D. M. Akob, and K. Küsel. 2013. Surprising abundance of Gallionella-related iron oxidizers in creek sediments at pH 4.4 or at high heavy metal concentrations. Frontiers in Terrestrial Microbiology, 4: 390.
  23. Keiner, R., A. Rusznyak, D. M. Akob, S. Hanf, K. Küsel, J. Popp, and T. Frosch. 2013. Raman spectroscopy – an innovative and versatile tool to follow the respirational activity and carbonate biomineralization of important cave bacteria. Analytical Chemistry, 85(18): 8708–8714.
  24. Risse-Buhl, U., M. Herrmann, D. M. Akob, P. Geesink, N. Pizani, W. Schönborn, K.-U. Totsche and K. Küsel. 2013. Phagotrophic protist diversity in the groundwater of a karstified aquifer - morphological and molecular analysis. Journal of Eukaryotic Microbiology, 60(5): 467–479.
  25. Gray, S. M., D. M. Akob, S. J. Green, and J. E. Kostka. 2012. The Bacterial Composition within the Sarracenia purpurea Model System: Local Scale Differences and the Relationship with the Other Members of the Food Web. PLoS One 7(12): e50969.
  26. Akob, D. M.*, S. H. Lee*, M. Sheth, K. Küsel, D. B. Watson, A. V. Palumbo, J. E. Kostka, and K.-J.Chin. 2012. Gene expression correlates with process rates quantified for sulfate- and Fe(III)-reducing bacteria in U(VI)-contaminated sediments. Frontiers in Terrestrial Microbiology 3:280. *Equal contribution
  27. Rusznyák, A., D. M. Akob, S. Nietzsche, K. Eusterhues, K. U. Totsche, T. R. Neu, T. Frosch, J. Popp, R. Keiner, J. Geletneky, L. Katzschmann, E.-D. Schulze, and K. Küsel. 2012. Calcite biomineralization by bacterial isolates from the recently discovered pristine karstic Herrenberg Cave. Applied and Environmental Microbiology 78(4): 1157–1167.
  28. Akob, D. M. and K. Küsel. 2011. Where microorganisms meet rocks in the Earth's Critical Zone. Biogeosciences 8: 3531-3543.
  29. Akob, D. M., L. Kerkhof, K. Küsel, D. B. Watson, A. V. Palumbo, and J. E. Kostka. 2011. Linking specific heterotrophic bacterial populations to bioreduction of uranium and nitrate using stable isotope probing in contaminated subsurface sediments. Applied and Environmental Microbiology 77(22): 8197–8200.
  30. Burkhardt, E.-M., S. Bischoff, D. M. Akob, G. Büchel, and K. Küsel. 2011. Heavy metal tolerance of Fe(III)-reducing microbial communities in a contaminated creek bank soil. Applied and Environmental Microbiology 77(9): 3132-3136.
  31. Lu, S., S. Gischkat, M. Reiche, D. M. Akob, K. B. Hallberg, and K. Küsel. 2010. Ecophysiology of Fe-cycling Bacteria in Acidic Sediments. Applied and Environmental Microbiology 76 (24): 8174-8183.
  32. Vishnivetskaya, T. A., C. C. Brandt, A. S. Madden, M. S. Drake, J. E. Kostka, D. M. Akob, K. Küsel, and A. V. Palumbo. 2010. Microbial Community Changes in Response to Ethanol or Methanol Amendments for U(VI) Reduction. Applied and Environmental Microbiology 76(17): 5728-5735.
  33. Sitte, J., D. M. Akob, C. Kaufmann, K. Finster, D. Banerjee, E.-M. Burkhardt, J. E. Kostka, A. Scheinost, G. Büchel and K. Küsel. 2010. Microbial Links between Sulfate Reduction and Metal Retention in Uranium and Heavy Metal-contaminated Soil. Applied and Environmental Microbiology 76(10): 3143–3152.
  34. Green, S. J., O. Prakash, T. M. Gihring, D. M. Akob, P. Jasrotia, P. M. Jardine, D. B. Watson, S. D. Brown, A. V. Palumbo and J. E. Kostka. 2010. Denitrifying bacteria from the terrestrial subsurface exposed to mixed waste contamination. Applied and Environmental Microbiology 76(10): 3244–3254.
  35. Burkhardt, E.-M., D. M. Akob, S. Bischoff, J. Sitte, J. E. Kostka, D. Banerjee, A. C. Scheinost, K. Küsel. 2010. Impact of Biostimulated Redox Processes on Metal Dynamics in an Iron-rich Creek Soil of a former Uranium Mining Area. Environmental Science & Technology 44(1): 177-183.
  36. Prakash, O., T. M. Gihring, D. D. Dalton, K.-J. Chin, S. J. Green, D. M. Akob, G. Wanger, and J. E. Kostka. 2010. Geobacter daltonii sp. nov., an iron(III)- and uranium(VI)-reducing bacterium isolated from the shallow subsurface exposed to mixed heavy metal and hydrocarbon contamination. International Journal of Systematic and Evolutionary Microbiology 60(3): 546-553.
  37. Akob, D. M., H. J. Mills, T. M Gihring, L. Kerkhof, J. W. Stucki, A. S. Anastacío, K.-J.Chin, K. Kusel, A. V. Palumbo, D. B. Watson, and J. E. Kostka. 2008. Functional Diversity and Electron Donor Dependence of Microbial Populations Capable of U(VI) Reduction in Radionuclide-Contaminated Subsurface Sediments. Applied and Environmental Microbiology 74(10): 3159-3170.
  38. Blöthe, M., D. M. Akob, K. Walter, J.E. Kostka, H. L. Drake, and K. Küsel. 2008. Heterogeneity of Fe(III)-reducing microorganisms in coal-mining lake sediments caused by a pH gradient. Applied and Environmental Microbiology 74(4): 1019–1029.
  39. Akob, D. M., H. J. Mills, & J. E. Kostka. 2007. Metabolically active microbial communities in uranium-contaminated subsurface sediments. FEMS Microbiology Ecology 59:95-107.
  40. Diaz, M. C., D. Akob, & C. S. Cary. 2004. Denaturing gradient gel electrophoresis of nitrifying microbes associated with tropical sponges. Proceedings of the 6th International Sponge Conference, Rapallo, Italy, 2002. Bollettino dei Musei e degli Istituti biologici dell'Università di Genova 68: 279–289.