Terrestrial deep shales and their interfaces are carbon-rich environments that represent a significant component of the U.S. energy portfolio. Energy resources in these environments have recently been accessed via hydraulic fracturing (i.e. “fracking”) technologies that introduce a complex mixture of biocides, surfactants, and other compounds into the shale matrix. This project aims to improve our… [Read More]

Climate change in the Arctic is progressing rapidly, thawing large areas of permafrost that contain nearly half of the world’s soil organic carbon. Once thawed, this soil carbon is first to be converted to dissolved organic carbon, which is then oxidized by microbes and sunlight to carbon dioxide. The conversion of this carbon pool to… [Read More]

Microbial metal and radionuclide reduction is central to a wide variety of processes, including biogeochemical metal cycling, hazardous organic matter degradation, and electricity generation in microbial fuel cells. Despite the potential benefit as alternative strategies for energy generation and radionuclide remediation, the molecular mechanism of microbial metal and radionuclide reduction remains poorly understood. Bacteria such… [Read More]

The zone of groundwater-surface water mixing, known as the Subsurface Interaction Zone (SIZ), is a critical and ubiquitous domain at the groundwater-surface water interface that strongly influences carbon and nitrogen cycling and regulates contaminant releases to surface waters. Researchers want to understand how groundwater-surface water mixing dynamics impact microbial communities. For this project, the work… [Read More]

Methanogens—anaerobic microbes that perform the final step of biomass degradation in the carbon cycle—convert carbon dioxide or monoxide, acetate, methanol, methyl-sulfides and methylamines into methane as part of their core metabolic system. They represent an integral piece of the global carbon cycle as an estimated 350 million tons of methane are produced yearly by methanogens…. [Read More]

Ectomycorrhizal fungi (EMF) are emerging as a model system for understanding microbial community dynamics and the linkages between microbial communities and ecosystem function. EMF provide their plant hosts with nutrients such as nitrogen, phosphorous, and water, in exchange for fixed carbon. Trade between the two partners constitutes a significant ecosystem flux in resources between plant… [Read More]

Permafrost is a key globally important ecosystem, storing massive amounts of carbon across a large area. Permafrost-associated soils cover nearly a quarter of the terrestrial land surface, contain more than a third of the world’s soil carbon, and are thawing due to climate change. The fate of the stored carbon is a key unknown in… [Read More]

Methane hydrates are pockets of methane trapped inside a solid structure of water and are often found in ocean floor sediments. Marine continental margin sediments that bear these methane hydrates are estimated to contain up to 2,000 billion metric tons of methane. Anaerobic methanotrophic archaea and sulfate-reducing bacteria (ANME-SRB consortia) account for the oxidation of… [Read More]