Engineering Shewanella oneidensis MR-1 for mixed waste bioremediation


An important area of research in our laboratory is investigating microorganisms with the potential for application in bioremediation of both organic and inorganic contaminants. One such interesting organism we are studying is Shewanella oneidensis MR-1.  This organism can grow both aerobically and anaerobically on a vast array of electron acceptors and plays an important biogeochemical role in metal reduction.  Shewanella oneidensis MR-1 also is capable of transforming carbon tetrachloride, a common subsurface contaminant.  In an effort to gain better understanding of the physiology of Shewanella oneidensis MR-1 for carbon tetrachloride transformation and metal reduction, MR-1 mutants lacking menaquinone formation capability were created and tested for their activity for carbon tetrachloride transformation and iron reduction.   In the process, we discovered that the wild type Shewanella oneidensis MR1 secretes a carbon tetrachloride-degrading factor. 

Recently we have focused our efforts on investigating the nature and activity of secreted factors for iron reduction and carbon tetrachloride transformation.  A putative quinone compound was characterized and found to be capable of reducing solid iron (III) oxide and carbon tetrachloride transformation.  Another aspect of our research is aimed at the fundamental understanding of the energy harvesting processes of MR-1 and the factors that impact this process.

Researchers working on this project: Aim Boonchayaanant and Shiang Fu