Changing Bacterial Growth Efficiencies across a Natural Nutrient Gradient in an Oligotrophic Estuary

Authors

Amber A. Kiger, Florida International UniversityFollow

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Geosciences

First Advisor's Name

William Anderson

First Advisor's Committee Title

Committee Co-Chair

Second Advisor's Name

Joseph N. Boyer

Second Advisor's Committee Title

Committee Co-Chair

Third Advisor's Name

Leonard J. Scinto

Third Advisor's Committee Title

Committee Member

Keywords

Bacterial Respiration, Bacterial Production, Bacterial Growth Efficiency, Stable Isotopes, Florida Bay

Date of Defense

3-27-2015

Abstract

Recent studies have characterized coastal estuarine systems as important components of the global carbon cycle. This study investigated carbon cycling through the microbial loop of Florida Bay by use of bacterial growth efficiency calculations. Bacterial production, bacterial respiration, and other environmental parameters were measured at three sites located along a historic phosphorus-limitation gradient in Florida Bay and compared to a relatively nutrient enriched site in Biscayne Bay. A new method for measuring bacterial respiration in oligotrophic waters involving tracing respiration of ¹³C-glucose was developed. The results of the study indicate that ¹³C tracer assays may provide a better means of measuring bacterial respiration in low nutrient environments than traditional dissolved oxygen consumption-based methods due to strong correlations between incubation length and δ¹³C values. Results also suggest that overall bacterial growth efficiency may be lower at the most nutrient limited sites.

Identifier

FI15032176

Recommended Citation

Kiger, Amber A., "Changing Bacterial Growth Efficiencies across a Natural Nutrient Gradient in an Oligotrophic Estuary" (2015). FIU Electronic Theses and Dissertations. 1758.
https://digitalcommons.fiu.edu/etd/1758