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. She investigates both contaminated and pristine environments. 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 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
- Affiliated Professor, Department of Biology at George Mason University, 2017-current.
- Affiliated Professor, Department of Geology, Appalachian State University, 2017- present.
- Adjunct Graduate Faculty, University of Alabama, Department of Biological Sciences, 2016-present.
- 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-current
- Postdoctoral Research Fellow, Friedrich-Schiller University Jena. 2010-2012
- Marie Curie Postdoctoral Research Fellow, Friedrich-Schiller University Jena. 2008-2010
- Associate Editor, Biogeosciences, 2016-present.
- Editorial Board Member, FEMS Microbiology Ecology, 2016-present.
- President-Elect American Society of Microbiology Washington, D.C. Branch, 2017-present.
- Editorial Board Member, Applied and Environmental Microbiology, January 1, 2018- December 31, 2020.
- 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, Baltimore, MD
- USGS Early Career Leadership Award, 2017
Science and Products
Acetylenotrophy: 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...Akob, Denise M.; Sutton, John M.; Fierst, Janna L.; Haase, Karl B.; Baesman, Shaun; Luther, George; Miller, Laurence G.; Oremland, Ronald S.
Common 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...Mumford, Adam C.; Akob, Denise M.; Klinges, J. Grace; Cozzarelli, Isabelle M.
Degradation 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)...Cozzarelli, Isabelle M.; Akob, Denise M.; Baedecker, Mary; Spencer, Tracey; Jaeschke, Jeanne B.; Dunlap, Darren S.; Mumford, Adam C.; Poret-Peterson, Amisha T.; Chambers, Douglas B.
Detection of diazotrophy in the acetylene-fermenting anaerobe Pelobacter sp. strain SFB93
Acetylene (C2H2) is a trace constituent of the present Earth's oxidizing atmosphere, reflecting a mixture of terrestrial and marine emissions from anthropogenic, biomass-burning, and unidentified biogenic sources. Fermentation of acetylene was serendipitously discovered during C2H2 block assays of N2O reductase, and Pelobacter acetylenicus was...Akob, Denise M.; Baesman, Shaun; Sutton, John M.; Fierst, Janna L.; Mumford, Adam; Shrestha, Yesha; Poret-Peterson, Amisha T.; Bennett, Stacy; Dunlap, Darren S.; Haase, Karl B.; Oremland, Ronald S.
Archaeal diversity and CO2 fixers in carbonate-/siliciclastic-rock groundwater ecosystems
Groundwater environments provide habitats for diverse microbial communities, and although Archaea usually represent a minor fraction of communities, they are involved in key biogeochemical cycles. We analysed the archaeal diversity within a mixed carbonate-rock/siliciclastic-rock aquifer system, vertically from surface soils to subsurface...Lazar, Cassandre Sara; Stoll, Wenke; Lehmann, Robert; Herrmann, Martina; Schwab, Valérie F.; Akob, Denise M.; Nawaz, Ali; Wubet, Tesfaye; Buscot, François; Totsche, Kai-Uwe; Küsel, Kirsten
Shifts in microbial community structure and function in surface waters impacted by unconventional oil and gas wastewater revealed by metagenomics
Unconventional oil and gas (UOG) production produces large quantities of wastewater with complex geochemistry and largely uncharacterized impacts on surface waters. In this study, we assessed shifts in microbial community structure and function in sediments and waters upstream and downstream from a UOG wastewater disposal facility. To do this,...Fahrenfeld, N.L.; Reyes, Hannah Delos; Eramo, Alessia; Akob, Denise M.; Mumford, Adam; Cozzarelli, Isabelle M.
Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota
Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples...Cozzarelli, Isabelle M.; Skalak, Katherine; Kent, D.B.; Engle, Mark A.; Benthem, Adam J.; Mumford, Adam; Haase, Karl B.; Farag, Aïda M.; Harper, David; Nagel, S. C.; Iwanowicz, Luke R.; Orem, William H.; Akob, Denise M.; Jaeschke, Jeanne B.; Galloway, Joel M.; Kohler, Matthias; Stoliker, Deborah L.; Jolly, Glenn D.
Complete genome sequence of the acetylene-fermenting Pelobacter sp. strain SFB93
Acetylene fermentation is a rare metabolism that was previously reported as being unique to Pelobacter acetylenicus. Here, we report the genome sequence of Pelobacter sp. strain SFB93, an acetylene-fermenting bacterium isolated from sediments collected in San Francisco Bay, CA.Sutton, John M.; Baesman, Shaun; Fierst, Janna L.; Poret-Peterson, Amisha T.; Oremland, Ronald S.; Dunlap, Darren S.; Akob, Denise M.
Complete genome sequences of two acetylene-fermenting Pelobacter acetylenicus strains
Acetylene fermentation is a rare metabolism that was serendipitously discovered during C2H2-block assays of N2O reductase. Here, we report the genome sequences of two type strains of acetylene-fermenting Pelobacter acetylenicus, the freshwater bacterium DSM 3246 and the estuarine bacterium DSM 3247.Sutton, John M.; Baesman, Shaun; Fierst, Janna L.; Poret-Peterson, Amisha T.; Oremland, Ronald S.; Dunlap, Darren S.; Akob, Denise M.
Microbially mediated barite dissolution in anoxic brines
Fluids injected into shale formations during hydraulic fracturing of black shale return with extraordinarily high total-dissolved-solids (TDS) and high concentrations of barium (Ba) and radium (Ra). Barite, BaSO4, has been implicated as a possible source of Ba as well as a problematic mineral scale that forms on internal well surfaces, often in...Ouyang, Bingjie; Akob, Denise M.; Dunlap, Darren S.; Renock, Devon
Environmental drivers of differences in microbial community structure in crude oil reservoirs across a methanogenic gradient
Stimulating in situ microbial communities in oil reservoirs to produce natural gas is a potentially viable strategy for recovering additional fossil fuel resources following traditional recovery operations. Little is known about what geochemical parameters drive microbial population dynamics in biodegraded, methanogenic oil reservoirs. We...Shelton, Jenna L.; Akob, Denise M.; McIntosh, Jennifer C.; Fierer, Noah; Spear, John R.; Warwick, Peter D.; McCray, John E.
Biological low pH Mn(II) oxidation in a manganese deposit influenced by metal-rich groundwater
The mechanisms, key organisms, and geochemical significance of biological low-pH Mn(II) oxidation are largely unexplored. Here, we investigated the structure of indigenous Mn(II)-oxidizing microbial communities in a secondary subsurface Mn oxide deposit influenced by acidic (pH 4.8) metal-rich groundwater in a former uranium mining area. Microbial...Bohu, Tsing; Akob, Denise M.; Abratis, Michael; Lazar, Cassandre S.; Küsel, Kirsten
Evidence of Unconventional Oil and Gas Wastewater Found in Surface Waters near Underground Injection Site
These are the first published studies to demonstrate water-quality impacts to a surface stream due to activities at an unconventional oil and gas wastewater deep well injection disposal site.
In a study of 13 hydraulically fractured shale gas wells in north-central Pennsylvania, USGS researchers found that the microbiology and organic chemistry of the produced waters varied widely from well to well.