The effect of the marine cyanobacterium (Trichodesmium erythraeum) on iron speciation in seawater

Iron is an essential micronutrient for growth of all phytoplankton, and in particular cyanobacteria. It is hypothesised that conditions of iron starvation may influence the relative importance of mechanisms employed by microorganisms including release of superoxide and organic exudates rate into the extracellular environment. Overall, this thesis provides a modified ferrozine method for detection of dissolved total iron in the presence of high concentrations of organic ligands, as well as a better understanding of biochemical mechanisms by which the globally significant diazotrophic cyanobacterium Trichodesmium erythraeum (IMS101) potentially modifies the bioavailability of iron under various iron nutrition scenarios.