Background: Microbial interactions are not static but instead occur on a continuum from cooperation to competition, affected by the prevailing environmental conditions. Among these, nutrient availability is particularly important, as heterotrophic microorganisms can benefit from algal photosynthates while, at the same time, competing with the alga for essential nutrients such as nitrogen. Nutrient supply can therefore exert a strong influence on the outcome of an interaction.

Project Description: This project aims to investigate whether and how nutrient availability changes the outcome of the interaction between the alga Chlamydomonas reinhardtii and the soil-borne filamentous fungus Verticillium dahliae (Prockl et al., 2026). By systematically modifying growth medium compositions, including nitrogen and phosphorus concentrations, we will assess whether varying culturing conditions change the interaction outcome between the two partners. When shifts in interaction outcomes are observed, we will further explore potential mechanisms driving these changes.