Biological Sciences Division
Microbiology
Transmission electron micrograph cross-section of a cell following incubation with NH4 TcO4; the dark color is technetium precipitated in the outer membrane. Images by Alice Dohnolkova. Research supported by DOE-OBER.
Bioprecipitation of radionuclides by Shewanella oneidensis MR-1. Electron micrograph of an unstained cell following incubation with uranyl acetate (left); the dark color that defines the cell is precipitated uranium.
The Microbiology group is comprised of microbial physiologists and ecologists, molecular biologists, and soil scientists. Major areas of research include biogeochemistry, microbial systems biology, soil and sediment microbiology, and development of rapid and sensitive methods of detecting and characterizing biothreat organisms and microbial communities.
Biogeochemistry is the study of how microbes impact water chemistry and the physical and chemical properties of surfaces, and how these in turn influence the behavior of microbes. Scientists in the group study the biogeochemistry of Shewanella oneidensis, which is able to transform metals and radionuclides such as chromium, uranium, and technetium to less toxic, mobile forms.
Microbial systems biology combines the use of highly controlled and reproducible culturing systems; protein, RNA, and metabolite analysis; targeted mutations; and computational modeling. Together, these methods build extensive understanding of cellular responses and their underlying regulatory networks. Two major model systems are being studied using systems biology approaches: Shewanella oneidensis (above) and defined syntrophic co-cultures. Syntrophy is a microbial interaction where two microbes require each another to obtain energy for growth. The use of a systems biology approach to studying simple two-organism systems provides an important stepping stone in understanding the details of how complex microbial communities interact at the molecular level.
Contact: Allan Konopka, Technical Leader
