Profile of Rick Colwell, new SBI faculty member in the College of Oceanic and Atmospheric Sciences

Posted: June 1, 2006

The Subsurface Biosphere Initiative would like to welcome Dr. Rick Colwell, a geomicrobiologist who will join the faculty of the College of Oceanic and Atmospheric Sciences (COAS) in June 2006. Rick has been a scientist at the Idaho National Laboratory (INL) since 1986 where his research has focused on microbial communities in subsurface environments. Rick’s position is in part funded by the Subsurface Biosphere Initiative and we are delighted about the expertise he brings to campus.

Below is a short interview designed to introduce Rick. Please contact him (rcolwell@coas.oregonstate.edu) if you would like more information about his research – he is excited about the potential for new collaborations at OSU.

Photo of Rick working with a multi-level sampler used to characterize the aquifer chemistry and microbiology at the Idaho National Laboratory's Test Area North. This is a site where Colwell and his collaboartors are studying TCE co-metabolism by methanotrophic microbes. (Photo by Sean O'Connell.)

How did you become interested in geomicrobiology and the subsurface biosphere?

I became interested in working in this field through my early experience at the Idaho National Laboratory. In the late 1980s the Department of Energy sponsored research to explore the subsurface biosphere. The program manager of this Subsurface Science Program required interdisciplinary collaboration among investigators in order to answer complex questions related to these deep geological environments and thereby broke the traditional language and context barriers that divide disciplines. It became clear to me that microbiological studies of these habitats needed to integrate an understanding of the physical and chemical environment in which the organisms grow. I also became intrigued by the difficulties of studying microbes from the subsurface; it is strikingly heterogeneous and actually quite remote despite the fact that the habitable subsurface is not far beneath us. Even the task of collecting representative, uncontaminated samples from the deep earth became an exciting challenge that prompted close teamwork.

What motivates your research?

I enjoy studying unique microbial habitats, the microbes in those habitats, and trying to work out what controls their survival in those locations. My goal is to understand how integrated microbiological systems function. When possible, I like to work iteratively with modelers – my research and experimentation helps to determine realistic input variables that the modelers need to accurately describe the system. Together, we hope to develop a better understanding of the system that can improve our ability to predict how microbial activities matter in a selected environment.

For example, an exciting current collaboration is my work with Jerry Dickens, a climate change modeler at Rice University and Bill Ussler, a geochemist at the Monterey Bay Aquarium Institute. Together, we are interested in the amount of methane produced by methanogens in deep marine sediments, what controls the rates of methanogenesis, and how that biogenic methane factors into the global carbon cycle. Our methanogenic rate experiments with a methanogen from the seafloor sustained under conditions representative of deep sediments aim to provide data for Jerry’s carbon cycling models and our experimental parameters (e.g., pressure, temperature, methane concentration) are framed by Bill’s thermodynamic calculations.

I also like the exploratory aspects of geomicrobiology. It is undeniably exciting to puzzle out the identity, activity, and constraints of a microbial community that has not been described. The research starts out with basic questions such as, “What organisms are present? Where do they exist? What are they capable of?” Later, we move to hypothesis driven experimentation.

Transmission electron microscope photo of Methanoculleus submarinus. This new species of methanogen was captured from sediments 246 m below the seafloor in the Nankai Trough off the coast of Japan and is being used in Rick's methanogenesis rate experiments. (Photo by Henry Aldrich.)

Are you doing anything else related to the microbiology of methane hydrates -- the ice-like substance that traps methane in sea floor sediments?

In addition to the methanogenic rate experiments and modeling we are also investigating the small scale control that methane hydrates or other seafloor sediment characteristics have on the type and numbers of microbes in the sediments. For this work I am a part of a team with Marta Torres (OSU professor of Chemical Oceanography) and we will be receiving new hydrate samples this summer. The samples will come from closely spaced, deep marine sediments obtained from off the coast of India and will compare the microbial community, geochemistry, and sedimentology of sediment layers that contain methane hydrates with layers that don’t. The goal is to better understand the microbial distribution in and around methane hydrates.

One of your research projects focuses on TCE contamination at the Idaho National Laboratory. Can you describe it?

A portion of the aquifer at the INL is contaminated with TCE, a common groundwater contaminant that was once used as a cleaning agent. The TCE is gradually disappearing from the aquifer by natural means and we have good evidence that this disappearance is due, in part, to the activity of methane-consuming microbes (methanotrophs). Interestingly, methane-producing microbes also in the groundwater seem to sustain this process. The EPA and the Idaho Department of Environmental Quality have accepted “monitored natural attenuation” as the most appropriate cleanup solution for part of this contaminant plume. In other words, the system is cleaning itself up and the process only needs to be monitored over time. But the complete story regarding the cleanup is still not known. We don’t know the rates at which the methanotrophs co-metabolize or destroy the TCE nor do we have a clear idea of what factors control this activity.

I am working on a project funded by DOE Office of Science that is trying to understand the system better. We are placing reactors into the aquifer where we can control aquifer flow rate and methane availability and we want to derive in situ rates for the cometabolism of TCE. We will also take samples of the microbial community and work with them in the lab to model TCE transformation, look at gene expression, and the production of particular proteins that are unique to methanotrophs. Another collaborator will use heavy isotopes to trace the path of methane, the microbe’s food source, in the system. When integrated, we hope this research will provide a systems level of understanding of the methanotrophs in the aquifer and how biological and abiological processes are coupled.

Rick is also an enthusiastic fisherman and soccer player. He caught this Yellowstone cutthroat on the Gros Ventre River near Jackson, WY last summer. (Photo by Taylor Eighmy.)

What are you looking forward to about coming to OSU?

I’m excited about the community – this is really a thriving environment for the type of collaboration and interdisciplinary work I like to do. There are few places in the country that have this collection of scientists and I’m excited for the chance to work with people in different disciplines related to earth science and geomicrobiology – from waste degradation, to methane hydrates, to fine-scale colonization of geological materials, and maybe hydrogen production. At the same time, I hope to continue my collaborations with researchers at the Idaho National Laboratory and at other national labs and I hope to bring opportunities to OSU by helping to be a bridge to those institutions. For example, I’d like to encourage students to consider research projects that would include internships at the INL. Such internships would benefit the scientists at both institutions.

What types of teaching will you do at OSU?

At INL I worked with some students, for example summer interns, but I didn’t have the opportunity to work with students as extensively as I will here. I am really looking forward to exploring ideas with them. I plan to supervise graduate students and look forward to developing a lab team that will hopefully grow to include one or more post-docs and undergraduates as well. I will also teach one class a year in COAS – perhaps a geomicrobiology class since that’s my area of expertise. I hope a class like this will be useful to an interdisciplinary group of students, for example students who are in the IGERT Earth's Subsurface Biosphere Program.

Rick arrives on campus in late June and can be reached at rcolwell@coas.oregonstate.edu. To learn more about geomicrobiology and the Idaho National Laboratory, he also suggests visiting the following web pages: