Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited.The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.Cultivation of individual microbial species has been at the core of experimental microbiology for more than a century but offers only a glimpse into the collective metabolism, ecology and ecophysiological potential of natural microbial systems. Microbial communities rather than individual species generally control process rates and drive key biogeochemical cycles, including those that determine the transformation of environmental pollutants. While the relatively recent advances in molecular ecology and metagenomic-enabled studies of microbial communities have greatly advanced our understanding of natural and engineered systems, such systems are often not amenable to precise experimental manipulation. Controlled studies of model consortia comprised of multiple species that mediate important biological processes are essential for advancing our understanding of many diverse areas of microbial ecology. Model consortia studies may be especially pertinent to engineered and biotechnology relevant processes including; human and animal environments [1-3], processes relevant to bioremediation and natural attenuation [4-6], bacterially mediated wastewater treatment processes [7,8], and industrial b