Biogeography: do microbes have it?

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
William T. Williams (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Parke Rublee

Abstract: The purpose of this study was to use an empirical approach to assess microbial biogeography in freshwater lakes. The targeted, empirical approach was pursued in this work to 1) understand if the census-based methods are under-representing microbes in environmental samples, and 2) to determine if certain microbes are more "transportable" than others, and thus more widespread. Lake samples were collected from 7 clusters of lakes around the world and real-time quantitative PCR was used with 20 microbe-specific primers to assess presence and abundance of each target. The results showed that, for the target microbes, presence in lakes exceeded previous census based estimates that only 15% of microbes are detectable from more than one location. Target microbes were found at an average of 81.7% of sites worldwide, with two present at all lakes. No statistically significant correlation between either the Sørensen Similarity Index or the Bray-Curtis Similarity Index and distance between microbial communities was found in the overall data set. A post hoc analysis did find a statistically significant decrease in the Sørensen Index over distances up to 7500 km. However, the regression coefficient was low (1.40 x 10-5) indicated that this would only reduce the number of species by about 10% over this distance. The results of this work provide support for the "everything is everywhere" hypothesis, suggesting little geographic limitation of microbial distribution. Based on the results, further study with additional targets and an increased number of geographically dispersed lakes is warranted.

Additional Information

Publication
Thesis
Language: English
Date: 2011
Keywords
Aquatic, Biogeography, Cyanobacteria, Ecology, Microbiology, Real-time PCR
Subjects
Microbial ecology $x Research