Sources: Harry Beller, Jillian Banfield, Dan Hawkes
This past week (February 9, 2015) brought the third installment of the video “trilogy” related to the U.S. Department of Energy–Biological and Environmental Research (DOE–BER) Genome-to-Watershed Scientific Focus Area (SFA) 2.0 project. This video, entitled “SFA 2.0-Metabolic Potential,” narrated by ESD’s Jillian Banfield and Harry Beller, describes the powerful influence of metabolic potential— defined here as the collective metabolic capabilities of subsurface microbial communities and their impact on ecosystems.
In her opening narration, Banfield informs us of how little microbiologists knew (until a few decades ago) regarding many of the obscure microorganisms that populate the branches of the tree of life, and how they function in the environment around us. The development of metagenomics (the study of genetic material recovered directly from environmental samples, especially microbial community samples) has, according to Banfield, “provided a method by which to begin to assay these organisms and in fact can deliver genomic information, information about the metabolic potential of these organisms that would otherwise not have been possible.”
This information is especially important for examining the Earth’s subsurface. While much research has been done on the terrestrial surface and even the soil, the region below the soil zone, which is out of contact with the sun and solar-driven biosphere, is still very little understood. As Banfield says, “It is only through the application of methods such as metagenomics that we are beginning to be able to take an inventory of the kinds of organisms that exist in that region, and to start to build an understanding of the kinds of processes they mediate. This is absolutely critical if we are going to understand how microbes and microbial processes transform elements in the subsurface and interconnect Earth’s biogeochemical cycles.”
The potential environmental impact of these subsurface microbial communities cannot be overstated. As Beller says, “These communities mediate a lot of important biogeochemical cycles, such as the cycling of carbon, sulfur, nitrogen, and iron.” Importantly, and in contrast to humans and other “higher” organisms, “Microbes collectively have an incredible metabolic diversity. They can do things like break down wood, they can oxidize ammonia, they can respire rust. These capabilities can deeply influence biogeochemical cycles.”
The ultimate goal of SFA 2.0 is to develop a predictive understanding of biogeochemical cycles that are occurring in the subsurface and in their broader environment of the watershed. As Beller notes, “This can have global consequences if we are looking at greenhouse gases and climate change. Microbial communities can create a net influx or efflux of carbon dioxide, a greenhouse gas. They can also produce nitrous oxide, which is a potent greenhouse gas, or they can produce or consume methane, which is another potent greenhouse gas. And these gases that are produced in the subsurface can communicate with the external environment, either through transport of groundwater to rivers, for example, or diffusion of these gases up through the soil, exchanging with the atmosphere.”
Thus, it is essential to have a thorough understanding of what these communities are doing, how they are influencing biogeochemical cycles and their effects on greenhouse gases. The metabolic potential component of SFA 2.0 entails, as Beller states, “trying to nail down and define what the metabolic activities are of the subsurface biota under conditions of interest.”
To watch this just-released video, made by LBNL video producer Ivan Berry, go here »
To watch the two previous SFA 2.0-related videos, also made by LBNL video producer Ivan Berry, go to:
To read about these previous SFA 2.0 videos, go to:
- Predicting Subsurface Processes: Genome to Watershed Scales
- Williams ID’s Hot Moments in Cool Watershed
To read further about the Genomes-to-Watershed project and recent publications, visit the SFA 2.0 website »
Additional information about the project is provided through the following links: