Denise M Akob, Ph.D.
National Research Program
12201 Sunrise Valley Dr
Reston, VA 20192
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’s National Research Program in 2012. 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 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, National Research Program (Water), Microbiology and Molecular Ecology 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
Science and Products
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 diversity was highest in the Mn deposit compared...Bohu, Tsing; Akob, Denise M.; Abratis, Michael; Lazar, Cassandre S.; Küsel, Kirsten
Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site
Currently, >95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection...Kassotis, Christopher D.; Iwanowicz, Luke; Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam; Orem, William H.; Nagel, Susan C.
Wastewater disposal from unconventional oil and gas development degrades stream quality at a West Virginia injection facility
The development of unconventional oil and gas (UOG) resources has rapidly increased in recent years; however, the environmental impacts and risks are poorly understood. A single well can generate millions of liters of wastewater, representing a mixture of formation brine and injected hydraulic fracturing fluids. One of the most common methods for wastewater disposal is underground injection; we...Akob, Denise M.; Mumford, Adam; Orem, William H.; Engle, Mark A.; Klinges, Julia (Grace); Kent, Douglas B.; Cozzarelli, Isabelle M.
Dominance of 'Gallionella capsiferriformans' and heavy metal association with Gallionella-like stalks in metal-rich pH 6 mine water discharge
Heavy metal-contaminated, pH 6 mine water discharge created new streams and iron-rich terraces at a creek bank in a former uranium-mining area near Ronneburg, Germany. The transition from microoxic groundwater with ~5 mm Fe(II) to oxic surface water may provide a suitable habitat for microaerobic iron-oxidizing bacteria (FeOB). In this study, we investigated the potential contribution of these...Fabisch, Maria; Freyer, Gina; Johnson, Carol A.; Buchel, Georg; Akob, Denise M.; Neu, Thomas R.; Kusel, Kirsten
Organic and inorganic composition and microbiology of produced waters from Pennsylvania shale gas wells
Hydraulically fractured shales are becoming an increasingly important source of natural gas production in the United States. This process has been known to create up to 420 gallons of produced water (PW) per day, but the volume varies depending on the formation, and the characteristics of individual hydraulic fracture. PW from hydraulic fracturing of shales are comprised of injected fracturing...Akob, Denise M.; Cozzarelli, Isabelle M.; Dunlap, Darren S.; Rowan, Elisabeth L.; Lorah, Michelle M.
Characterization of pH dependent Mn(II) oxidation strategies and formation of a bixbyite-like phase by Mesorhizobium australicum T-G1
Despite the ubiquity of Mn oxides in natural environments, there are only a few observations of biological Mn(II) oxidation at pH < 6. The lack of low pH Mn-oxidizing bacteria (MOB) isolates limits our understanding of how pH influences biological Mn(II) oxidation in extreme environments. Here, we report that a novel MOB isolate, Mesorhizobium australicum strain T-G1, isolated from an acidic...Bohu, Tsing; Santelli, Cara M; Akob, Denise M.; Neu, Thomas R; Ciobota, Valerian; Rösch, Petra; Popp, Jürgen; Nietzsche, Sándor; Küsel, Kirsten
Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette
Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (...Beulig, Felix; Heuer, Verena B.; Akob, Denise M.; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten
Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds
The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater...Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten