Soils at the microscale

Soil is highly complex and heterogeneous at the microscale. We use different types of microbial models to uncover how microorganisms spatially self organize in soil, how they interact with each other and how all these aspects influence the organic matter decomposition.

** My first research line concerns with the degradation of large polysaccharides by microorganisms. We study how the degradation dynamics depends on diffrent types of extracellular enzymes involved. In particular we are interested in contrasting dynamics observed for enzymes with exo activity, that cut the polymers at the end of the chain, vs endo activity for enzymes that cut the polymer randomly. We are interested in the tradeoffs faced by microorganisms and finally the possibility of division of labor.

** My second research line concerns with the impact of the soil structure on the decomposition of soil organic matter. We model how microorganisms spread and colonize different types of pore networks, tacking into account different aspects of microbial decomposition dynamics. Furthermore we study how the enzyme kinetics, can be influenced by the accessibility to the substrate, i.e. by the complex pore geometry of the soil space.

Publications:

• Trade-offs faced by bacteria in decomposition of complex biopolymers, Ksenia Guseva, Moritz Mohrlok, Lauren Alteio, Hannes Schmidt, Shaul Polak and Christina Kaiser (In preparation)