Denise M. Akob, Ph.D.
Denise Akob is a Research Microbiologist for the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Dr. Denise M. Akob is a microbial ecologist and biogeochemist whose research aims to understand interactions between microbes and their environment and address effects of anthropogenic contaminants on environmental health and water quality. Her research focuses primarily on understanding microbial impacts on Cold War Biogeochemistry (uranium and chlorinated solvent contamination); energy production (either by mitigating degradation of contaminants (from hydraulic fracturing or oil spills) or by enhancing natural gas production); and carbon cycling. Dr. Akob joined the U.S. Geological Survey in 2012 as a research scientist in the Water Mission Area, and move to the Geology, Energy, and Minerals Science Center in 2020. For more information, please visit the Reston Microbiology Lab website.
Professional Experience
Research Microbiologist, U.S. Geological Survey, Geology, Energy, & Minerals Science Center, Reston Microbiology Laboratory, 2020-current
Affiliated Professor, Department of Biology at George Mason University, 2017-current
Affiliated Professor, Department of Geology, Appalachian State University, 2017-current
Affiliated Professor, Department of Geography and Planning, Appalachian State University, 2016-current
Affiliated Professor, Environmental Science and Policy Department at George Mason University, 2013-current
Research Microbiologist, U.S. Geological Survey, Water Mission Area, Reston Microbiology Laboratory, 2012-2020
Postdoctoral Research Fellow, Friedrich-Schiller University Jena, 2010-2012
Marie Curie Postdoctoral Research Fellow, Friedrich-Schiller University Jena, 2008-2010
Education and Certifications
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
Affiliations and Memberships*
Chair, 2025 Applied and Environmental Microbiology Gordon Research Conference
Chair, American Society for Microbiology’s Council on Microbial Sciences (COMS), 2023-2024
Vice Chair, American Society for Microbiology’s Council on Microbial Sciences (COMS), 2022-2023
Vice Chair, 2023 Applied and Environmental Microbiology Gordon Research Conference
Editorial Board Member, FEMS Microbiology Ecology, 2016-present
Editorial Board Member, Applied and Environmental Microbiology, January 1, 2018-present
Editorial Board Member, ISME Communications, 2020-present
Associate Editor, Biogeosciences, 2016-2023
Councilor, Washington, D.C. Branch of the American Society for Microbiology, 2021-2022
President, Washington, D.C. Branch of the American Society for Microbiology, 2019-2021
President-Elect, Washington, D.C. Branch of the American Society for Microbiology, 2017-2019
USGS Community for Data Integration’s Bioinformatics Community of Practice, co-organizer, 2017-present
USGS Eastern Water Science Series, co-organizer, 2017-present
Applied and Environmental Microbiology Gordon Research Seminar Mentor, July 15-16, 2017
USGS NRP-EB Weekly Science Series, co-organizer (2013-2017)
Geobiology Theme Chair, Goldschmidt 2015 25th Anniversary Meeting
Co-Chair for Session T50. Microbial Hydrocarbon Formation and Biodegradation: Organisms, Pathways, Environmental Limitations, and Isotope Signatures, 2015 Geological Society of America Annual Meeting
Honors and Awards
USGS Early Career Leadership Award, 2017
Science and Products
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Compositional analysis of formation water geochemistry and microbiology of commercial and carbon dioxide-rich wells in the southwestern United States
Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania
The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration o
Binning singletons: Mentoring through networking at ASM microbe 2019
Draft genome sequence of the Mn(II)-oxidizing bacterium Oxalobacteraceae sp. AB_14
Phylogenetic techniques in geomicrobiology
Organic geochemistry and toxicology of a stream impacted by unconventional oil and gas wastewater disposal operations
Microbial community composition of a hydrocarbon reservoir 40 years after a CO2 enhanced oil recovery flood
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
Acetylenotrophy: A hidden but ubiquitous microbial metabolism?
Common hydraulic fracturing fluid additives alter the structure and function of anaerobic microbial communities
Degradation of crude 4-MCHM (4-methylcyclohexanemethanol) in sediments from Elk River, West Virginia
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Publications
Filter Total Items: 43
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be key markers of OG wastewater releases when combineAuthorsIsabelle M. Cozzarelli, Douglas B. Kent, Martin A. Briggs, Mark A Engle, Adam Benthem, Katherine Skalak, Adam Mumford, Jeanne B. Jaeschke, Aida Farag, John W. Lane, Denise M. AkobCompositional analysis of formation water geochemistry and microbiology of commercial and carbon dioxide-rich wells in the southwestern United States
Studies of naturally occurring subsurface carbon dioxide (CO2) accumulations can provide useful information for potential CO2 injection projects; however, the microbial communities and formation water geochemistry of most reservoirs are understudied. Formation water and microbial biomass were sampled at four CO2-rich reservoir sites: two within Bravo Dome, a commercial CO2 field in New Mexico; oneAuthorsJenna L. Shelton, Robert S. Andrews, Denise M. Akob, Christina A. DeVera, Adam C. Mumford, Mark Engle, Michelle R. Plampin, Sean T. BrennanShale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania
The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration o
AuthorsAdam Mumford, Kelly O. Maloney, Denise M. Akob, Sarah Nettemann, Arianne Proctor, Jason Ditty, Luke Ulsamer, Josh Lookenbill, Isabelle M. CozzarelliBinning singletons: Mentoring through networking at ASM microbe 2019
The American Society for Microbiology (ASM) national conference, Microbe, is the flagship meeting for microbiologists across the globe. The presence of roughly 10,000 attendees provides enormous opportunities for networking and learning. However, such a large meeting can be intimidating to many, especially early career scientists, students, those attending alone, and those from historically underrAuthorsJoseph B. James, Amanda L. Gunn, Denise M. AkobDraft genome sequence of the Mn(II)-oxidizing bacterium Oxalobacteraceae sp. AB_14
Biological Mn(II) oxidation produces reactive manganese oxides that help to mitigate metal contamination in the environment. Here we present the genome of Oxalobacteraceae sp. AB_14, a species of Mn(II)-oxidizing bacteria (MOB) notable for its ability to catalyze Mn oxidation at low pH (5.5).AuthorsTimothy Bushman, Denise M. Akob, Tsing Bohu, Andrea Beyer, Tanja Woyke, Nicole Shapiro, Alla Lapidus, Hans-Peter Klenk, Kirsten KüselPhylogenetic techniques in geomicrobiology
Molecular biological techniques have revolutionized the field of geomicrobiology by providing researchers with robust techniques for identifying microorganisms and characterizing microbial communities in a wide variety of environments. These techniques have freed researchers from the constraints of classical culture-based microbiology and allowed the discovery of previously unknown phylogenetic diAuthorsDenise M. Akob, Adam C. Mumford, Darren S. Dunlop, Amisha T. Poret-PetersonOrganic geochemistry and toxicology of a stream impacted by unconventional oil and gas wastewater disposal operations
Water and sediment extracts samples were analyzed for extractable hydrocarbons by gas chromatography/mass spectrometry (GC/MS) using an Agilent (Agilent Technologies, Palo Alto, CA, USA) 7890 series GC and 5975 electron ionization (EI) mass selective detector (MSD) operated in scan mode. Agilent ChemStation software was used for data acquisition and analysis (version E.02.00.493 on GC/MS computerAuthorsWilliam H. Orem, Matthew S. Varonka, Lynn M. Crosby, Karl B. Haase, Keith A. Loftin, Michelle L. Hladik, Denise M. Akob, Calin Tatu, Adam C. Mumford, Jeanne B. Jaeschke, Anne L. Bates, Tiffani Schell, Isabelle M. CozzarelliMicrobial community composition of a hydrocarbon reservoir 40 years after a CO2 enhanced oil recovery flood
Injecting CO2 into depleted oil reservoirs to extract additional crude oil is a common enhanced oil recovery (CO2-EOR) technique. However, little is known about how in situ microbial communities may be impacted by CO2 flooding, or if any permanent microbiological changes occur after flooding has ceased. Formation water was collected from an oil field that was flooded for CO2-EOR in the 1980s, inclAuthorsJenna L. Shelton, Robert S. Andrews, Denise M. Akob, Christina A. DeVera, Adam C. Mumford, John E. McCray, Jennifer C. McIntoshAn initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
A study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission and Montclair State University, was designed to compare pesticide concentrations and the presence and prevalence of amphibian pathogens between natural ponds and two types of created wetlands, excavated ponds and stormwater basins, throughout the New Jersey Pinelands. The study described hereinAuthorsKelly L. Smalling, John F. Bunnell, Jonathan Cohl, Kristin M. Romanok, Lisa Hazard, Kirsten Monsen, Denise M. Akob, Angela M. Hansen, Michelle L. Hladik, Nicole Abdallah, Quratulain Ahmed, Araba Assan, Matthew D. De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna WilliamsAcetylenotrophy: A hidden but ubiquitous microbial metabolism?
Acetylene (IUPAC name: ethyne) is a colorless, gaseous hydrocarbon, composed of two triple bonded carbon atoms attached to hydrogens (C2H2). When microbiologists and biogeochemists think of acetylene, they immediately think of its use as an inhibitory compound of certain microbial processes and a tracer for nitrogen fixation. However, what is less widely known is that anaerobic and aerobic microorAuthorsDenise M. Akob, John M. Sutton, Janna L. Fierst, Karl B. Haase, Shaun Baesman, George Luther, Laurence G. Miller, Ronald S. OremlandCommon hydraulic fracturing fluid additives alter the structure and function of anaerobic microbial communities
The development of unconventional oil and gas (UOG) resources results in the production of large volumes of wastewater containing a complex mixture of hydraulic fracturing chemical additives and components from the formation. The release of these wastewaters into the environment poses potential risks that are poorly understood. Microbial communities in stream sediments form the base of the food chAuthorsAdam C. Mumford, Denise M. Akob, J. Grace Klinges, Isabelle M. CozzarelliDegradation of crude 4-MCHM (4-methylcyclohexanemethanol) in sediments from Elk River, West Virginia
In January 2014, approximately 37 800 L of crude 4-methylcyclohexanemethanol (crude MCHM) spilled into the Elk River, West Virginia. To understand the long-term fate of 4-MCHM, we conducted experiments under environmentally relevant conditions to assess the potential for the 2 primary compounds in crude MCHM (1) to undergo biodegradation and (2) for sediments to serve as a long-term source of 4-MCAuthorsIsabelle M. Cozzarelli, Denise M. Akob, Mary Jo Baedecker, Tracey Spencer, Jeanne B. Jaeschke, Darren S. Dunlap, Adam C. Mumford, Amisha T. Poret-Peterson, Douglas B. ChambersNon-USGS Publications**
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 (DOI: 10.1021/ac401699d).Gray, S. M., D. M. Akob, S. J. Green, and J. E. Kostka. 2012. The predictability of bacterial composition within the Sarracenia purpurea model system: local scale differences and relationships with the other members of the food web. PLoS One 7(12): e50969.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.Risse-Buhl, U., M. Herrmann, D. M. Akob, P. Geesink, N. Pizani, W. Schönborn, K.-U. Totsche and K. Küsel. 2012 Phagotrophic protist diversity in the groundwater of a karstic aquifer - morphological and molecular analysis. Journal of Eukaryotic Microbiology, 60(5): 467–479 (DOI: 10.1111/jeu.12054.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.Akob, D. M. and K. Küsel. 2011. Where microorganisms meet rocks in the Earth's Critical Zone. Biogeosciences 8, 3531-3543.
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
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.
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.
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.
Sitte, J., D. M. Akob, C. Kaufmann, K. Finster, D. Banerjee, E.-M. Burkhardt, J. E. Kostka, A. Scheinost, Georg 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.
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.
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.O. Prakash, T.M. Gihring, D.D. Dalton, K.-J. Chin, S.J. Green, D.M. Akob, G. Wanger, 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: 546-553.D. M. Akob, H. J. Mills, T. M. Gihring, L. Kerkhof, J. W. Stucki, Kuk-Jeong Chin, Kirsten Kuesel, Anthony V. Palumbo, David B. Watson, and Joel 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: 3159-3170.
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): 1019–102.
D. M. Akob, H. J. Mills, D. L. Swofford, J. E. Kostka. 2007. Metabolically-Active Microbial Communities in Uranium-Contaminated Subsurface Sediments. FEMS Microbiology Ecology 59: 95-107.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government