Microbiology research is currently undergoing a revolutionary transition from the study of primarily monocultures to the study of natural and synthetic microbial communities. Microbial consortia play a key role in chronic medical infections and the human gut microbiome and have been implicated in many chronic medical conditions including ulcerative colitus. Microbial consortia are also used in water treatment plants, toxic site remediation and biofuel production. Understanding the behavior of microbial communities in response to a disturbance and their subsequent control remains an outstanding scientific challenge. This project will provide a first step toward the goal of developing analytic and modeling techniques that will allow rational design of synthetic microbial communities that are robust and controllable.
There are theories suggesting that diversification in a microbial community may enhance stability, robustness and increase efficiency; however a precise quantitative understanding of the advantages that a consortium provides for its members is needed. This project seeks to experimentally and theoretically determine the impact of specific metabolic interactions within a microbial community on emergent properties like enhanced stress tolerance or increased biomass production. The project will use tools of dynamical systems, like invariant manifold theory and stability of invariant sets, to analyze models of microbial communities. Methods of partial differential equations will be used to extend this analysis to interacting spatially segregated communities. These models will precisely quantify the relationship between the number of defined microbial interactions and the magnitude of improvement on both consortia efficiency and enhanced tolerance. This will provide a systems biology basis for characterizing consortial behaviors and a scalable methodology to compare the benefits of membership in a microbial community to the costs for each individual. This information is fundamental to understanding microbial community persistence and will provide a rational framework for controlling both unwanted and desirable consortia. Prior research has yielded preliminary results on the conditions necessary for increased biomass production in specialized binary communities versus a monoculture and has demonstrated the existence of invariant manifolds that simplify the analysis for many types of microbial communities. This project extends this work by building experimental synthetic communities with well-defined metabolic roles, measuring the synthetic community's characteristics like biomass production and robustness to perturbations and constructing mathematical models for more complex and spatially segregated communities.
