(94c) Molecular Level in Silico Analysis of Mass and Energy Flows in Microbial Communities

Complex microbial communities drive the Earth's biogeochemical cycles. In spite of their importance, the biochemical interactions within these communities are not yet well understood, nor are many in silico methodologies available for studying them. Three in silico methodologies based on stoichiometric network analysis were developed for studying mass and energy flows in microbial communities on the molecular level. Each approach has distinct advantages and disadvantages suitable for analyzing systems with different degrees of complexity and different levels a priori knowledge. These methodologies were tested and compared using the extensive data from the phototrophic, thermophilic mat communities at Octopus and Mushroom Springs in Yellowstone National Park. The models included three community guild members: cyanobacteria, filamentous anoxygenic phototrophs, and sulfate reducing bacteria. The in silico models were used to explore fundamental microbial ecology questions including the prediction and explanation for measured relative abundances of the oxygenic phototrophic primary producer cyanobacteria and the filamentous anoxygenic phototrophic bacteria. The three approaches represent a flexible toolbox which can be rapidly adapted to study other microbial systems with a variety of electron donors and acceptors on scales ranging from individual cells in a pure culture to entire ecosystems represented by metagenomic data.