The thermodynamic model is applicable to slow-growing communities in which metabolic byproducts from reactions close to thermodynamic equilibrium create crossfeeding networks. We derive the principle of maximum free energy dissipation in this model and demonstrate how functional convergence emerges despite taxonomic differences in crossfeeding partnerships. The model successfully predicts functional convergence in anaerobic digesters, showing how crossfeeding networks stabilize at low dilution rates.
The auxotroph model examines communities where organisms are genetically unable to synthesize essential nutrients (e.g. amino acids) and must rely on crossfeeding from other species. Using graphical and algebraic methods, our approach reveals how amino acid crossfeeding creates higher-order interaction networks that enhance community resilience to environmental fluctuations through metabolic complementarity. Applied to experimental data from synthetic E. coli communities, the model accurately predicted the survival of 3 out of 4 strains in a 14-member auxotroph community, correctly identifying key mutualistic crossfeeding partnerships.