Factors influencing the abundance, community composition and activity states of bacterioplankton from the tidal freshwater James River

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.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2010

Author dc:creator

• Luria, Catherine

Contributors dc:contributor

• Paul Bukaveckas

• bacteria
• rivers and estuaries
• phytoplankton
• eutrophication
• metagenomics
• microbial ecology
• Biology
• Life Sciences

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/110

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1109