Virus-driven reprogramming of bacterial traits

Main area:Marine biology
Target group:Biology, Biochemistry, Bioinformatics
Educational level:Masters, Bachelor
Project description:

In the marine environment, 30-40 % of the bacteria are infected and killed by viruses, and the interactions between viruses and bacteria are central to the ecology and evolution of marine microbial communities with significant effects on biogeochemical cycles. Following infection, lytic viruses hijack the cellular machinery of the bacteria to produce new viruses and kill the host, whereas temperate viruses integrate their genome into the host chromosome, where it remains dormant (prophage) until conditions favor its reactivation and lysis of the host cell. The prophage genome represents a potential metabolic burden and molecular time bomb in the host genome which at any time can induce and kill its host. However, temperate viruses also have direct influence on the genetic composition and architecture of the host they infect and the incorporated virus genome is replicated along with the host genome. Consequently, prophages can potentially enrich the host cell with new beneficial genes, and recent studies have shown that the global marine viral community encodes most of the metabolic properties required for performing the basic bacterial functions8, in addition to numerous other bacterial fitness factors (e.g. virulence, antibiotic resistance and quorum sensing genes9). These auxiliary metabolic genes (AMG’s) are dispersed and exchanged among marine bacteria via viral infections, applying strong selection forces that drive functional diversification and evolution in marine microbial communities. The project will explore the capacity of viruses to encode key bacterial traits and disseminate these functions among marine bacterial communities, using the Vibrio genus (vibrios) as a model for the analysis of phage-driven microbial evolution. The objective of the project is to decipher the genetic mechanisms and environmental controls of the dissemination of virus-encoded bacterial traits and their implications for the functional capacity and evolution of marine Vibrio communities.

Keywords:prophages, viruses, disease, aquaculture, marine microbial ecology
Supervisor(s):  Mathias Middelboe