Competition strategies driving resource partitioning in chitin degrading communities

Resource competition shapes microbial community dynamics and function. In polysaccharide-degrading communities, primary degraders secrete monomer-releasing enzymes and exploiters consume released products without investing in the enzymes themselves. By investigating competitive strategies between several chitin degraders and N-acetylglucosamine (GlcNAc) exploiters, we uncover several interacting factors, including GlcNAc liberation rates, diffusive loss, and resource partitioning between competitors, which determine community viability and growth dynamics at early stages of chitin degradation.

In this talk, we focus on the case in which exploiters inhibit degraders by siphoning away limited GlcNAc flux during the early, critical stages of particle degradation, when degraders must overcome diffusive GlcNAc loss to sustain chitinase production. In analogy to the Allee effect in population biology, these effects lead to sensitive dependences on initial species densities for a community to thrive. This has important implications for interpreting community-scale data in light of dynamics, including initial conditions to broaden our understand of community viability and function.