Raman chemical imaging and Fluorescence Lifetime microscopy studies of chromate uptake, localization, and reduction in remediating bacteria
Abstract
Bioremediation, a natural process of detoxifying environment has the potential to be incorporated for effective treatment of toxic 'superfund' sites. One of the major challenges in effective implementation of bioremediative strategies is the current lack of a thorough understanding of the microbial processes that are responsible for the remediation of contaminated sites. This project aims to develop novel approaches, involving effective integration of ultrasensitive Raman spectroscopy and Fluorescence Lifetime imaging techniques with nanobiotechnology, to study intracellular chemical activities within single microorganisms. Two unique methods of delivering nanoprobes into the usually inaccessible intracellular microenvironment of cells are used to study cellular chromate reduction activities in a ubiquitous metal reducer S. oneidensis MR-1 at single cell level. After careful optimization of SERS substrate delivery, sulfate and nitrate competition assays were detailed at single cell and multi-cell resolutions. Given the potential use of this environmentally important strain for biotechnological and bioremediation purposes, it is necessary that we increase our understanding of the fundamental biological processes enabling chromate reduction before improving environmental applications of S. oneidensis MR-1. The significance of this strain is reflected in the formation of the "Shewanella Federation", a multi-conglomerate Department of Energy (DOE)-funded group that applies bioinformatic, genomic and proteomic techniques to define the systems biology of Shewanella. The ability to map processes through the use of sensitive spectroscopic tools will complement these efforts by defining not only what processes are occurring, but also where they are occurring within the cell.
Degree
Ph.D.
Advisors
Irudayaraj, Purdue University.
Subject Area
Microbiology|Biomedical engineering|Biophysics
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