Bacteriophages, or viruses that infect bacteria (aka “phages”), are recognized as critically important for carbon cycling and other natural processes. Phages influence these processes by causing bacterial death and modifying bacterial metabolism. How phages affect the abundances of bacteria in engineered water systems remains largely unknown.

Understanding what viruses influence bacteria in water and wastewater systems is essential as these bacteria can make humans sick, degrade water quality, and influence the efficacy of treatment processes. 

We work closely with Prof. Melissa Duhaime in Ecology and Evolutionary Biology and apply experimental and computational approaches to understand phage impacts on water quality. For example, we reanalyzed previous studies that are publicly available to understand global patterns of drinking water viruses, including the effect of drinking water treatment processes on viral diversity. One interesting finding from that work is that in drinking water distribution systems that use residual disinfectants (like chlorine), viruses have lower diversity than drinking water distribution systems that use no residual disinfectant. 

We have also worked on improving methods for recovering viruses from complex water samples for metagenomic sequencing.  We found that ultrafiltration concentration resulted in higher concentration factors and in better viral DNA quality than iron chlorine concentration methods. In on-going work, we apply spike-in standards and metagenomic sequencing to quantify all viruses in water samples and to help define detection and quantification limits of specific viruses.