Deciphering the role of phages as top-down and bottom-up regulators of freshwater ecosystems
Due to methodological difficulties our knowledge about the role of phages in freshwater ecosystems is very limited. Therefore, the proposed project aims to address the following main research questions:
1. What are the effects of phages as bottom-up regulators on the carbon flux of freshwater ecosystems?
2. Is there a difference in the effect of phages as top-down regulators of bacterial communities depending on the attributes of the impacted bacteria or on properties of the phages?
3. What is the role of ssDNA phages in shaping freshwater bacterial communities and ecosystems?
In order to achieve these aims, the project will use novel microbial ecology and biogeochemistry methods that allow the simultaneous unbiased analysis of the two main aquatic phage groups (dsDNA & ssDNA phages), and the identification of changes in the organic matter pool of freshwaters due to the lyses of bacterial biomass by phages (i.e., viral shunt).
Three interconnected work-packages will be performed to achieve the goals: WP-1 a mesocosm study in 2017, and WP-2 and WP-3, two chemostat experiments in 2018 and 2019, respectively.
The results of the project will provide valid answers to the main research questions, increase global understanding of the ecological importance of aquatic viruses and supply valuable data for issues of broader scientific and social importance such as climate change modelling or phage therapy development.