A New Approach to Understand Complex Microbial Communities


Microorganisms control the rates of numerous processes in the environment including contaminant degradation and biogeochemical cycling of carbon and other nutrients; however, they rarely perform these functions alone or in isolation. Microorganisms exist in communities whose dynamic activities and responses to environmental influences remain poorly understood. Building on the increasing availability of microbial species whose genomes have been sequenced, researchers at Oak Ridge National Laboratory developed a model system of three microbial species to probe the details of microbial community interactions and physiology. Co-cultures containing a Clostridia, Desulfovibrio and Geobacter species were used to examine carbon and energy flow in an anaerobic microbial community. The availability of genomic information for each microbe enabled the use of powerful techniques for analysis of gene and protein expression to understand the dynamic shifts in metabolism resulting from environmental changes and/or association or competition within the microbial community. The model system is applicable to numerous environmental processes where fermentative production of simple organic acids (by Clostridia) drives microbial metabolism such as sulfate-reduction (by Desulfovibrio) or iron reduction (by Geobacter). This project will advance our predictive understanding of microbial community interactions in a manner not previously possible and will increase our understanding of environmental processes relevant to DOE such as carbon and nutrient cycling in soils and contaminant biotransformation in contaminated groundwater.


Miller, L. D., J. J. Mosher, A. Venkateswaran, Z. K. Yang, A. V. Palumbo, T. J. Phelps, M. Podar, C. W. Schadt, and M. Keller. 2010. Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments. BMC Microbiology. 10:149