Urea and nickel utilization in marine cyanobacteria as evaluated by incubation, proteomic, and uptake techniques
Goepfert, Tyler J.
MetadataShow full item record
LocationEquatorial Pacific Upwelling
South Pacific Gyre
KeywordPrimary productivity; Nitrogen cycle; Melville (Ship) Cruise MV1015; Kilo Moana (Ship) Cruise KM1128
Nitrogen and trace metal biogeochemical effects on phytoplankton productivity were compared through whole water bottle incubations and proteomic evaluation of in situ harvested particulate matter from two distinct oceanographic regions: the Equatorial Pacific Upwelling and the South Pacific Gyre. Phytoplankton growth in both regions was stimulated by nitrogen additions with equivalent response from nitrate and urea. In the gyre, trace metal additions did not yield a chlorophyll response, however nickel treatments showed evidence of nickel-limited nitrogen fixation. In contrast, cell growth at the upwelling site was primarily iron-limited and iron plus urea or nitrate additions further enhanced the chlorophyll response, indicative of secondary nitrogen limitation. Nitrogen stress proteins and urea transporters from cyanobacteria in these field sites showed similar trends, with both increasing in waters containing lower dissolved inorganic nitrogen. Together with bottle incubations, the abundant urea transporters and nitrogen stress proteins indicate the importance of urea in these field sites. Representative cyanobacteria cultures (Synechococcus strain WH8020, and Prochlorococcus strain MED4) were evaluated to constrain urea uptake rates and explore the potential for compound specific uptake rates. Together, results from this study indicate that urea may represent an under-recognized component of the marine microbial nitrogen cycle.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2013
Showing items related by title, author, creator and subject.
The ecology of colonial radiolarians : their colony morphology, trophic interactions and associations, behavior, distribution, and the photosynthesis of their symbionts Swanberg, Neil Ralph (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1979-08)Colonial radiolarians (Spumellaria) are among the most common and abundant large zooplankton, but they have been little studied by modern biologists. Colonies were found on 98% of epipelagic diving stations in the period ...
A determination of air-sea gas exchange and upper ocean biological production from five noble gases and tritiugenic helium-3 Stanley, Rachel H. R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)The five noble gases (helium, neon, argon, krypton, and xenon) are biologically and chemically inert, making them ideal oceanographic tracers. Additionally, the noble gases have a wide range of solubilities and molecular ...
Elkins, Lynne J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-02)To explore the ability of melting mafic lithologies to produce alkaline ocean-island basalts (OIB), an experimental study was carried out measuring clinopyroxene (Cpx)- melt and garnet (Gt)-melt partition coefficients ...