Ph,D., Massachusetts Institute of Technology, 1962.
Editor in Chief designate, Antonie van Leeuwenhoek International Journal of Microbiology
Editorial Boards, Applied and Environmental Microbiology, BioMetals, International Biodeterioration and Biodegradation
Room: E623A MSB, Tel: 312-996-9608
Heavy Metal Resistance in Bacteria
This laboratory studies the molecular genetics and biochemistry of how bacterial cells cope with toxic overload of inorganic cations and anions. The genes for most of the resistance systems that we study reside on bacterial plasmids. We currently study arsenic, mercury, and silver resistances in a wide range of Gram negative and Gram positive bacteria.
Approaches including DNA sequencing, site-directed mutagenesis, PCR cloning, RT-PCR transcript analysis, overexpression of proteins, protein structure and function by activity assays, CD and NMR analysis, and membrane transport studies are used to understand each system. Current efforts include the new silver resistance system found on plasmids in hospital-exposed bacteria; mercury resistance determinants from Minamata Bay, Japan; arsenic resistance, oxidation and reduction with Gram positive and negative bacteria, and the cadmium resistance ATPase that is closely homologous to those defective in the human hereditary diseases, Menkes' syndrome and Wilson's disease. We collaborate with biotechnology startup companies concerned with microbial genomics, bioremediation and biomining.
In recent years, these studies have been useful in providing a basic understanding of systems that are shared by organisms causing human disease and those that are found in the environment . In some cases, metal-resistance genes directly affect bacterial pathogenesis. The plasmid resistance systems also have been of general interest in revealing novel regulatory genes, and enzymatic and membrane transport systems, for which homologous examples are found elsewhere in bacteria and eukaryotes.