DOI
https://doi.org/10.25772/R2K8-XF17
Defense Date
2010
Document Type
Thesis
Degree Name
Master of Science
Department
Biology
First Advisor
Paul Bukaveckas
Abstract
Aquatic bacteria respond to changing environmental conditions through a variety of mechanisms including changes in abundance, shifts in community composition and variable activity states. In the tidal-freshwater James River, variation in bacterial abundance was linked to nutrient availability and autochthonous production with highest bacterial densities associated with low-nutrient, high-chlorophyll a conditions. Laboratory experiments revealed that bacterial growth rates were nutrient limited at the low-nutrient site, while co-limitation (nutrients, glucose, light) was apparent at the high nutrient site. Despite large differences in abundance, community composition was similar based on TRFLP and 16S rDNA pyrosequencing. Community similarity was lower among rRNA libraries suggesting that variable activity states are prevalent in natural communities. Rare taxa were more likely to be metabolically active and were capable of dramatic growth under microcosm conditions.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
July 2010