Microbial model systems and ecological theories
In the last two decades, cultivation-independent molecular biological methods have allowed revealing the wealth of microbial diversity in terrestrial and aquatic environments and raising microbial biodiversity inventories (i.e. bacteria, protists and fungi). While the development of these methods undoubtedly has radically changed the way scientists observe microorganisms in their environmental setting, our knowledge regarding the underlying mechanisms driving microbial patterns, interactions and processes in nature is still rudimentary. It is further unclear if the ecological theories, derived from community dynamics of higher organisms, also apply to microorganisms. However, ecological theory is particularly crucial to provide predictions for microbial communities.
Within our group we intend to address the question how microbial biodiversity and interactions are related to ecosystem functioning, stability and resilience. Of particular importance is the mechanistic analysis of direct and indirect interactions (i.e. trophic, chemical etc.) between microorganisms within and across trophic levels. Lack of understanding the complexity of microbial communities and their interactions to date makes it unlikely to accurately predict their responses in the field. While manipulative experiments would be the choice to reveal the mechanisms, these seem hardly feasible for natural microbial communities. We therefore favor the explicit theory-driven use of miniaturized microbial model systems as a complementary approach to field observations. Such systems are powerful experimental tools since they offer several advantages such as easy control, high number of replication, rapid generation times, post-hoc analysis and range of experimental scale. Through the reduction of complexity simplified model systems allow testing theories and hypotheses about ecological processes and establishing the plausibility of mechanisms presumed to be operating in natural systems.
See also an article about our model systems in the local newspaper (Leipziger Volkszeitung):