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EMSL Project ID


Bacterial strains such as Shewanella oneidensis strain MR-1 are key organisms in the bioremediation of metals due to their ability to enzymatically reduce and precipitate a diverse range of heavy metals and radionuclides. Central to this reduction is the capacity of anaerobic respiration where the organism uses alternate electron acceptors in the respiratory process. Shewanella can transition between these conditions, and the changes in protein expression patterns through out these changes will aid in the understanding of the reduction mechanisms in the organism.
We will focus on several key electron acceptors that would be of interest to different groups and, at the same time, represent environmentally relevant conditions. These should include: oxygen, fumarate, nitrate, thiosulfate, Fe(III)NTA and HFO (or ferrihydrite). The experiments will be carried out using controlled batch cultures (the MCDL facilities at PNNL). We will focus on the transition phase when the cultures are switched from one respiratory condition to another (Fig. 1). Oxygen-limited cultures will be used as a reference/starting point to transition to all test conditions. The samples for expression analysis (as well as for other types of analyses) will be collected in 10-15 minute intervals. Growth parameters, substrate concentrations and rates of physiological processes will be measured during this transition.

Project Details

Project type
Exploratory Research
Start Date
End Date


Principal Investigator

Alex Beliaev
Environmental Molecular Sciences Laboratory

Team Members

Grigoriy Pinchuk
Pacific Northwest National Laboratory

Matthew Marshall
Pacific Northwest National Laboratory

Margaret Romine
Pacific Northwest National Laboratory

Mary Lipton
Environmental Molecular Sciences Laboratory