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Author Analytic: Ammerman, James W., W. B Glover, R. H. Sada Ruvalcaba , M. J.D. McRae
Center: CSCOR
Title Analytic: Continuous Underway Measurement of Microbial Enzyme Activities in Surface Waters of the Mississippi River Plume and the Louisiana Shelf
Author Monographic: In: Atwood, Donald K., W.F. Graham and C. B. Grimes (eds.)
Title Monographic: Nutrient-Enhanced Coastal Ocean Productivity, Proceedings of the April 1994 Synthesis Workshop
Place of Publication: Baton Rouge, LA
Publisher Name: Louisiana Sea Grant College Program
Date of Publication: 1995
Location In Work: 1-8
Extent of Work: 119
 Notes: Individual workshop paper
Keywords: land and resource use: eutrophication/hypoxia/nutrients, microbes, enzymes, bacteria, underway measurements, alkaline phosphatase, Gulf of Mexico, Mississippi River plume
Stressor: Resource and land use
Reprint Status: On Request (05/17/02)
Author Subsidiary: Texas A&M University/Dept. of Oceanography
 Availability: coastalocean@noaa.gov
Type: Book Chapter
 Abstract: Cell-surface enzymes are crucial to the bacterial utilization of polymeric carbon and nitrogen sources, as well as of organic phosphates. Such enzymes are also important to phytoplankton, but bacteria appear to dominate most of cell-surface enzyme activities measured in the field with the possible exception of alkaline phosphatase. Bacterial ectoenzyme activities have been shown to be good indicators of the state of bacterial carbon, nitrogen, or phosphorus nutrition, depending on the enzyme assayed. However, like most other biochemical and molecular measurements, cell-surface enzyme activities have been limited to discreet water samples. We have recently developed a continuous underway method for measuring microbial enzyme activities using high-sensitivity fluorescent substrates. This method has been sucessfully applied to alkaline phosphatase measurements and peptidase measurements in the surface waters of the Mississippi River Plume and the Louisiana shelf. The alkaline phosphatase measurements demonstrate a large area of phosphate-deficient surface water in the plume region. Furthermore, since these enzyme activities can be measured continuously, we can achieve spatial and temporal coverage nearly comparable to physical oceanographic measurements.
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