Abstract
Viruses are extremely abundant in aquatic ecosystems typically outnumbering bacteria by a factor of 10. Their numbers and ubiquity give them the potential to control structure and function of microbial communities. As viruses are parasites they can only replicate within their host. It is often assumed that viruses have a very narrow host range however a growing number of observations are indicating that aquatic viruses consist of broad host range viruses. This project will investigate the occurence of broad host range cyanophages (viruses infecting cyanobacteria) in subtropical lakes by using standard viral lysis assays and fluorescently labeled cyanophages of Microcystis aeruginosa or/and Cylindrospermopsis raciborskii. The labeled cyanophages will be used as probes to identify the infection susceptibility of different cyanobacterial hosts in a set of Australian subtropical lakes. The probes will allow for simple quanitfication of viral host specificity under in situ conditions as labeled cyanophages could be added directly to lake water samples. Besides the fundamental research interest on host specificity of cyanophages and their natural control of toxic cyanobacterial blooms in freshwaters, my proposed study will serve the restoration of lakes and water reservoirs, since understanding of cyanophage-induced cyanobacterial collapse might be used to control and remove toxic algal blooms.
Sweden