Research interests in our laboratory are in biofilm growth and control in drinking and industrial water systems; the fate, transport and survival of pathogens in biofilm systems; and the physiology of biofilm bacteria. Our focus has been primarily in low-nutrient aquatic environments. We have been using and developing methods for use in environmental systems that include RT-PCR, microarrays, community profile analysis by DGGE, distinguishing live/dead cells by PCR analysis. For determining physiological aspects of biofilm vs. suspended cells, methods development has included microarrays and proteomics, with model organisms being Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhimurium. We also have a focus in integrating information obtained on biofilm formation using the scanning confocal laser microscope with models that can be used to predict biofilm behavior. Recent work also includes investigating the microbial ecology of nitrification in oligotrophic water systems using traditional culturing and molecular methods.