Research Faculty #26

There has been increasing interest in the biology and ecology of viruses and other pathogens that infect microalgae. Viruses that infect bacteria and phytoplankton play a key role in the dynamics of organisms and nutrients in marine and freshwater ecosystems, and consequently also affect nutrient and energy cycling. A primary research focus of my laboratory is to understand the biology and ecology of viruses that infect microalgae and cyanobacteria. Research interests include 1) discerning the effect of viruses on primary productivity and phytoplankton population dynamics; 2) isolating and characterizing novel viruses from marine environments; 3) developing molecular approaches for enumerating and identifying viruses; 4) determining the temporal and spatial distribution of specific viruses; 5) identifying mechanisms regulating viral abundance in nature; and 6) understanding the biology of these viruses and the infection process and exploring the molecular evolution and genetic diversity of viruses in nature.

As part of these studies, we have isolated viruses that infect ecologically important phytoplankton and cyanobacteria including toxic bloom formers. We have developed PCR primers specific for the DNA polymerase genes of viruses that infect microalgae. These primers have been used to amplify DNA from a number of different viruses infecting marine phytoplankton, as well as from natural virus communities. Sequence analysis indicates that these viruses belong to a single family, and are most closely related to herpes viruses. These viruses can occur in seawater at concentrations > 105 ml-1. Viruses that infect cyanobacteria occur at even higher concentrations, and 106 infectious units ml-1, can be found in some coastal waters. Our research will continue to investigate the role of viruses in aquatic ecosystems.