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Identification of Metal Reductases (NABIR)

EMSL Project ID


Central to the NABIR goal to develop the scientific basis for in situ remediation of radioactive contaminants is the fundamental understanding of microorganisms with dissmilatory metal reducing activity. In order to effectively exploit these bacteria, it is necessary to know which enzymes and pathways are involved. Additionally, it would be advantageous to understand the similarities and differences of these pathways across different bacteria for effective deployment in bioremediation, as well as to identify new microbes capable of such activities. Most approaches to identify these enzymes or enzyme complexes rely on biochemical purification to homogeneity with subsequent N-terminal sequencing of digested peptides. However, loss of activity before achieving purity often necessitates repetition of the entire process. Newly developed proteomics capabilities at PNNL allow for the identification of many proteins from a single sample through mass spectrometry analysis. Thus the need for absolute sample purity is eliminated, and potential enzymatic targets for metal reduction are reduced to a small subset of proteins whose metal reduction activity can be related by genetic manipulation. In the proposed research, we will use high throughput proteomics to identify the proteins responsible for metal reduction activity across 5 organisms: Shewanella oneidensis MR-1, Geobacter sulfurreducens, Pseudomonas fluorescens, Desulfovibrio desulfuricans G20, and Deinococcus radiodurans allowing inferences to be made as to the similarities and differences of activities throughout the organisms.

Project Details

Project type
Exploratory Research
Start Date
End Date


Principal Investigator

Mary Lipton
Environmental Molecular Sciences Laboratory