J Weitz Georgia Institute of Technology
Thursday 30th October 2014 -
11:55 to 12:30
INI Seminar Room 1
Viruses are ubiquitous in the marine environment and can infect and lyse target cells. Lysis of marine host cells releases cellular debris. This debris can then be taken up by non-targeted cells, stimulating microbial production. This redirection of cellular biomass by viruses is termed the "viral shunt". Quantitative estimates of the strength of the viral shunt, first established in the late 1990s, were inferred from estimates of host and viral density, host carbon content, and viral lysis rates. Yet, these and subsequent estimates provide limited information on potential dynamic drivers and the likelihood of the viral shunt to cause other feedbacks. Here, I offer two recent perspectives on the viral shunt. First, I present an ab-initio model of the carbon and nutrient content of virus particles. In doing so, I show how the elemental stoihcoimetry of virus particles differs from that of microbial host cells. The consequences of this difference include both changes in the expected release of elements in the viral shunt as well as the potential reservoir of elements in virus particles. Second, I present a new model of a microbial community that incorporates virus-host interactions and the viral shunt. I show how virus presence in the environment may stimulate certain ecosystem-scale functions, including increased recycling of organic matter and gross primary productivity. I close with a brief discussion of ongoing challenges of translating and testing these results in the field.