Gardening of bacteria

By bringing together national and international expertise within the fields of marine microbial ecology and molecular biology, a team led by NORCE and University of Bergen will investigate how bacterivorous mixotrophy affects the structure and function of the marine pelagic food web and assess the impact of mixotrophy on carbon flow and food web efficiency.

Mixotrophic algae combine photosynthesis and the uptake of bacteria for their nutrition. At elevated carbon and low nutrient concentrations, algae might “garden” bacteria to keep up in the competition for scarce nutrients in the ocean. There is a consensus that the ability to “run” a mixotrophic mode is rather the rule than an exception among marine phytoplankton. However, how mixotrophy affects the marine microbial food web is so far underexplored, mainly due to the lack of suitable methods. During the three year project, funded by the Research Council of Norway (project number 280414, MIXsTRUCT - Impact of mixotrophy on the structure of the marine pelagic food web), we will apply state-of-the-art technology and develop an approach suitable to quantify and identify mixotrophy in controlled experiments and natural marine microbial communities. Furthermore, we will examine how input of dissolved organic carbon (e.g. due to increased runoff from land) affects the contribution of mixotrophy to marine microbial production. MIXsTRUCT also aims to raise early awareness around scientific topics and cooperates with a local school.