EAGER: Leveraging advances in stable isotope probing to investigate phylogenetic organization in prokaryotic activity

West Virginia University Research Corporation, Morgantown WV

Investigators

Abstract

It is estimated that there are more than one trillion species of microorganisms Earth, but only a small fraction of them have been isolated, grown in the laboratory and fully characterized. This project will support the development of a novel approach that links the identification of the vast diversity of microorganisms with their role in consuming different carbon sources in soil without the need to isolate and cultivate them in the laboratory. It will take advantage of the latest developments in DNA sequencing and environmental chemistry. Specifically, this research will also test whether related microorganisms decompose the same forms of carbon in soil, resulting a major advance in microbial evolution and ecology. This work will also result in an important new tool to characterize microbial biodiversity in order to better predict the cycling of carbon in soil. This Early-concept Grant for Exploratory Research (EAGER) project will investigate the role of evolutionary history in determining microbial function via the study of an integral ecosystem process: carbon decomposition. A novel method that quantitatively measures stable isotope incorporation into the nucleic acids of individual microbial "species" (or phylotypes) will be used to determine which microorganisms are decomposing and assimilating specific constituents of the soil carbon pool. The soil carbon compounds to be considered include important representatives from plants and microbes (e.g. cellulose, proteins) and range from quickly mineralized (i.e. glucose and amino acids) to recalcitrant (i.e. cellulose) carbon sources. Comparing the activity and phylogeny of microorganisms will allow a determination of whether closely related organisms tend to consume the same carbon sources. To determine if the functional roles of microbial phylotypes and phylogenetic groups are consistent under different environmental conditions, soils with differing soil organic carbon characteristics will be studied. As soil organic carbon quantity and chemistry influences the composition and activity of microbial communities, this comparison will provide insight into which organisms and activities are consistent under different environmental conditions. If evolutionary history is found to be a determinant of microbial function, phylogeny/function relationships will be characterized in order to understand how the composition of microbial communities affects their functioning within ecosystems. In addition to charting new ground in environmental microbiology, this project will support two undergraduate student researchers and an early-career investigator.