BE/IDEA: Development of a Instrument for in situ Measurement of Microbial Enzyme Activities in Aquatic Ecosystems

  • Ammerman, James J.W. (PI)
  • Chant, Robert (CoPI)
  • Klinkhammer, Gary P. (CoPI)

Project Details

Description

Microbial cell-surface enzymes (ectoenzymes) are important agents of polymer hydrolysis in aquatic environments and indicators of the state of microbial carbon, nitrogen, or phosphorus nutrition. However, like most other microbial metabolic rate measurements in aquatic environments, ectoenzyme activity measurements have usually been limited to manual assays with discrete water samples. An instrument for continuous underway measurements of microbial enzyme activities using high-sensitivity fluorescent substrates has recently been developed. This instrument has been used aboard ship to map the ectoenzyme activities alkaline phosphatase and leucine aminopeptidase in the surface waters of the Mississippi River plume. With this instrument these enzyme activities can be mapped in much the same way that temperature, salinity, phytoplankton fluorescence, and other parameters are mapped from a research ship while underway. However, this system is limited to horizontal mapping of water samples continuously pumped from the surface and requires frequent operator intervention. This Biocomplexity Instrumentation Development for Environmental Activities (IDEA) project will take the next much larger step. The research and education team includes a microbial ecologist (Dr. J. Ammerman) and a geochemist (Dr. G. Klinkhammer), both of whom have interests and expertise in sensor development, a coastal physical oceanographer and modeler (Dr. R. Chant), and a non-faculty education specialist (Mr. E. Simms). The goal of this project is to develop a remotely operated instrument for measurement of microbial enzyme activities and to deploy it at the Rutgers University Long-term Ecosystem Observatory at 15 meters depth, called LEO-15, for periods of weeks to months. This instrument is called the Multiple Enzyme Analyzer (MEA), and should be capable of the simultaneous measurement of up to four different enzyme activities. A simple mooring with biological, chemical, and physical sensors will be deployed near the enzyme analyzer to help provide a context for the microbial rate measurements (along with additional data from LEO-15). The enzyme and related data will be analyzed with time-series methods, spectral analysis techniques, statistical modeling, and other techniques to gain insight into microbial processes in the coastal zone. A second deployment of the MEA will take place at the new Martha's Vineyard Coastal Observatory (Woods Hole Oceanographic Institution), along with an automated flow cytometer and image analyzer used for plankton cell counting and sorting. This instrument is under development by Dr. R. Olson and colleagues with Biocomplexity IDEA support. This enzyme analyzer will provide continuous real time microbial metabolic rate measurements on time scales that are currently unavailable. Such measurements will add an important biological component to the extensive chemical and physical measurements that can be made at ocean observatories. In addition, education efforts in aquatic microbiology will include training workshops for primary and secondary school teachers followed by lesson development and implementation, as well as university undergraduate and graduate student research and education

StatusFinished
Effective start/end date9/15/028/31/08

Funding

  • National Science Foundation: $1,311,855.00

Fingerprint

Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.