Metal and Radionuclide Bioremediation by Starvation Promoter-Driven Combinatorial Bacteria
EMSL Project ID
1958
Abstract
We propose to use genetic and protein engineering approaches to construct P. putida strains with superior capacity to remediate chromate and, possibly also radionuclides, at the DOE sites. Such strains will possess an improved chromate reductase activity that is capable of reducing high priority radionuclides uranium and technitium as well, and be able to express this enzyme at a high level under the harsh DOE site conditions. Our recent findings have generated hypotheses relevant to this objective.One of these is that several proteins known for unrelated activities, such as nitroreductase, and NADPH:FMN oxidoreductase, can reduce chromate. These proteins evidently have a broad substrate range, encouraging the notion that they may be active also in catalyzing the reduction of uranium and technitium. We have cloned some of the relevant genes and have purified their products, More such genes are being cloned and their products purified. The pure proteins and the source bacteria will be examined for their chromate, uranium, and technetium reducing activity and reduction products. DNA shuffling will be used to develop a super-efficient chromate reductase that ideally will also be efficient in handling the radionuclides. We need EMSL collaboration to work with the radionuclides as well as to characterize the products of chromate reduction.
Project Details
Project type
Exploratory Research
Start Date
2000-04-24
End Date
2003-01-29
Status
Closed
Released Data Link
Team
Principal Investigator