My work is focused on understanding membrane transport, signaling, stress response and tolerance phenotypes in microbial systems. I study both engineered and environmental microbes. I use a variety of microbiological, biochemical and systems biology tools to examine environmentally important organisms such as sulfate and metal reducing bacteria as well as cyanobacteria. I have specific interest in signaling mechanisms in novel non-model organisms like Pseudomonas stuzeri, Desulfovibrio vulgaris and Microcoleus vaginatus and have conducted detailed studies in model organisms such as Agrobacterium tumefaciens. I develop tools, and use host and protein engineering strategies, to improve the production of fuels and chemicals, and conduct bioremediation, using model microbes such as Escherichia coli and Saccharomyces cerevisiae.