Todd R. Miller, PhD
Research Associate, University of Wisconsin-Madison, Center for Limnology and Department of Bacteriology
Postdoctoral Scholar, Johns Hopkins, Bloomberg School of Public Health
PhD, Marine Estuarine Environmental Sciences, Marine Molecular Biology and Biotechnology, University of Maryland, College Park, MD
BS, Biological Sciences, St. Norbert College, DePere, WI
Interests and Expertise
Research in my laboratory is concerned with characterizing factors that regulate human exposure to naturally occurring or anthropogenic toxins in water or wastewater. I am particularly interested in understanding how microbial communities affect the concentration, fate and toxicity of harmful chemicals in the aquatic environment. The ultimate goal of this research is to formulate models (either numerical or conceptual) of toxin production, release, and degradation in aquatic systems. Since the diversity of biochemical functions performed by microorganisms is only beginning to be realized, this research is both challenging and intriguing.
Research & Teaching Overview
Currently my research is focused on two project areas:
Biological transformations of phenyl urea pesticides. The environmental fate and toxicity of chemical pollutants is complicated by the large number of potential biological transformations that a chemical may undergo once released into the environment. In some cases the breakdown products may be more harmful than the parent compounds. This appears to be the case for phenyl urea pesticides such as Linuron, Diuron, Triclocarban and related compounds, which are slowly transformed by bacteria to carcinogenic chloroanilines in the environment. All of these compounds, as well as their chloroaniline degradation products have estimated half- lives exceeding 100 days in freshwater and have the potential to bioaccumulate in freshwater organisms. We are investigating how microbial processes control the distribution of these compounds and their toxic end- products in freshwater and freshwater resources including "seafood," drinking water and groundwater. These transformations are studied in laboratory scale microcosms, in fish bioassays, and in the natural environment through field surveys.
Freshwater harmful algal blooms. Recurrent nuisance and/or toxic algal blooms are a consistent problem in eutrophic lakes, rivers and coastal oceans. In recreational eutrophic lakes hepatotoxins and neurotoxins produced by cyanobacteria are an ongoing threat to public health. Beaches in many regions are monitored and closed by local health authorities when problems are suspected. However, despite these closings acute illnesses of swimmers are still reported. This illustrates the need for better monitoring methods and greater understanding of factors controlling human exposure to toxins. Our research is directed at understanding cyanobacterial toxin dynamics in lakes relative to the molecular ecology of cyanobacteria. We are also developing new autonomous monitoring systems for cyanobacteria and their toxins based on sensor-equipped buoy platforms. Finally, we are developing models of cyanobacterial growth and toxin production, which we hope will aid in reducing human exposure to algal toxins.
Miller,T.R., A. L. Delcher, S. L. Salzberg, E. Saunders, J. C. Detter, and R. U. Halden. 2010. Genome sequence of the dioxin- mineralizing bacterium Sphingomonas wittichii RW1. J. Bacteriol. 192:6101-6102.
Miller, T. R., D. R. Colquhoun, and R. U. Halden. 2010. Identification of wastewater bacteria involved in the degradation of Triclocarban and its non-chlorinated congener. J. Hazard. Mater. 183:766-772.
Miller, T.R., S. Chillrud, J. Heidler and R.U. Halden. 2008. Fate of triclosan and evidence for reductive dechlorination of triclocarban in estuarine sediments. Environ. Sci. and Technol. 42:4570–4576.
Miller, T.R., M. P. Franklin and R. U. Halden. 2007. Bacterial community analysis of shallow groundwater undergoing sequential anaerobic and aerobic chloroethene biotransformation. FEMS Microbiol. Ecol. 60:299-311.
Reid, I. N., W. B. Sparks, S. Lubow, M. McGrath, M. Livio, J. Valenti, K. R. Sowers, H. D. Shukla, S. MacAuley, T. Miller, R. Suvanasuthi, R. Belas, A. Colman, F. T. Robb, P. DasSarma, J. A. Müller, J. A. Coker, R. Cavicchioli, F. Chen and S. DasSarma. 2006. Terrestrial models for extraterrestrial life: methanogens and halophiles at martian temperatures. Intl. J. Astrobiol. 5:89-97.
Miller, T. R. and R. Belas. 2006. Motility is involved in Silicibacter sp. TM1040 interaction with dinoflagellates. Environ. Microbiol. 8:1648-1659.
Dong, W., G. Xie, T. R. Miller, M. P. Franklin, T. P. Oxenberg, E. J. Bouwer, W. P. Ball, and R. U. Halden. 2006. Sorption and bioreduction of hexavalent uranium at a military facility by the Chesapeake Bay. Environ. Pollut.132:132-142.
Moran, M. A., A. Buchan, J. M. González, J. F. Heidelberg, W. B. Whitman, R. P. Kiene, J. R. Henriksen, G. M. King, R. Belas, C. Fuqua, L. Brinkac, M. Lewis, S. Johri, B. Weaver, G. Pai, J. A. Eisen, E. Rahe, W. M. Sheldon, W. Ye, T. R. Miller, J. Carlton, D. A. Rasko, I. T. Paulsen, Q. Ren, S. C. Daugherty, R. T. Deboy, R. J. Dodson, A. S. Durkin, R. Madupu, W. C. Nelson, S. A. Sullivan, M. J. Rosovitz, D. H. Haft, J. Selengut, and N. Ward. 2004. Genome sequence of Silicibacter pomeroyi reveals adaptations to the marine environment. Nature. 432: 910 - 913
Miller, T. R., and R. Belas. 2004. Chemotaxis of Silicibacter sp. TM1040 toward dinoflagellate products. Appl. Environ. Microbiol. 70:4692-4701
Miller, T. R., and R. Belas. 2004. Dimethylsulfoniopropionate (DMSP) metabolism by Pfiesteria associated Roseobacter. Appl. Environ. Micrbiol. 70:3383-3391
Miller, T. R., and R. Belas. 2003. Pfiesteria piscicida, P. shumwayae, and other Pfiesteria-like dinoflagellates. Res. Microbiol. 154:85-90.
Quesenberry, M. S., K. Saito, D. Krupatkina, J. Robledo, T. Drgon, W. Pecher, N. O'Leary, M. Alavi, T. Miller, R. Schneider, R. Belas, J. Deeds, A. Place, Y. Zohar, and G. Vasta. 2003. Bioassay for ichthyocidal activity of Pfiesteria piscicida: characterization of a culture flask assay format. J. Appl. Phycol. 14:241-254.
Alavi, M., T. Miller, K. Erlandson, R. Schneider, and R. Belas. 2001. Bacterial community associated with Pfiesteria-like dinoflagellate cultures. Environ. Microbiol. 3:380-396.