Interactions of cadmium, zinc, and phosphorus in marine Synechococcus : field uptake, physiological and proteomic studies
Citable URI
https://hdl.handle.net/1912/4645Location
Costa Rica Upwelling domeDOI
10.1575/1912/4645Abstract
A combination of uptake field studies on natural phytoplankton assemblages and
laboratory proteomic and physiological experiments on cyanobacterial isolates were
conducted investigating the interactions of cadmium (Cd), zinc (Zn), and phosphorus (P)
in marine Synechococcus. Enriched stable isotope field uptake studies of 110Cd in the
Costa Rica Upwelling dome, a Synechococcus feature, showed that uptake of Cd occurs
in waters shallower than 40 m, correlates positively with chlorophyll a concentrations
and is roughly equivalent to the calculated upwelling flux of cadmium inside the dome.
In laboratory experiments, Synechococcus WH5701 cells exposed to low picomolar
quantities of free Cd under Zn deficiency show similar growth rates to no added Cd
treatments during exponential growth phase, but show differences in relative abundances
of many proteins involved in carbon and sulfur metabolism suggesting a great metabolic
impact. During stationary phase, chronic Cd exposure in this coastal isolate causes an
increase in relative chlorophyll a fluorescence and faster mortality rates. The interactions
of acute Cd exposure at low picomolar levels with Zn and phosphate (PO4
3-) were
investigated in Synechococcus WH8102, an open ocean isolate. The presence of Zn
appears vital to the response of the organism to different PO4
3- concentrations.
Comparisons with literature transcriptome analyses of PO4
3- stress show similar increases
in relative abundance of PO4
3- stress response proteins including a PO4
3- binding protein
and a Zn-requiring alkaline phosphatase. A bacterial metallothionein, a Zn-associated
protein, appears to be correlated with proteins present under low PO4
3- conditions.
Together, these experiments suggest that the interactions of Cd and Zn can affect
Synechococcus and play a role in the acquisition of PO4
3-.
Description
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2011
Collections
Suggested Citation
Thesis: Cox, Alysia D., "Interactions of cadmium, zinc, and phosphorus in marine Synechococcus : field uptake, physiological and proteomic studies", 2011-06, DOI:10.1575/1912/4645, https://hdl.handle.net/1912/4645Related items
Showing items related by title, author, creator and subject.
-
Seasonal oscillations in a mid-latitude ocean with barriers to deep flow
Firing, Eric (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1978-08)A two-layer linear analytic model is used to study the response of the mid-latitude ocean to the seasonal variation of the windstress. The most important component of the response is a barotropic quasi-steady Sverdrup ... -
Geoacoustic inversion by mode amplitude perturbation
Poole, Travis L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-02)This thesis introduces an algorithm for inverting for the geoacoustic properties of the seafloor in shallow water. The input data required by the algorithm are estimates of the amplitudes of the normal modes excited by ... -
Emulating the fast-start swimming performance of the chain pickerel (Esox niger) using a mechanical fish design
Watts, Matthew Nicholas (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-09)Mean maximum start-up accelerations and velocities achieved by the fast-start specialist, northern pike, are reported at 120 ms-2 and 4 ms-1, respectively (Harper and Blake, 1990). In this thesis, a simple mechanical system ...