Postdoctoral Research Associate
M32 Guyot Hall
Princeton NJ 08544
(609) 258-7438 (Tel.)
What is the identity of environmental trace-metal chelating agents, what are their sources and what is their significance? These decade old questions remain still largely unanswered because of analytical difficulties arising from highly complex organic matrixes and low concentrations. Yet, we know that iron, along with other trace metals, can determine primary productivity, nitrogen fixation and microbial community composition in vast areas of the oceans. We also know that iron and other trace metals are often quantitatively (>99.9%) bound to strong chelating agents of unknown identity in surface waters. To unveil the pool of trace-metal chelating agents in culture media and environmental samples, I develop and apply new analytical techniques using high-resolution liquid-chromatography mass-spectrometry (see Chelomics project ) and combine them with established ways of trace metal speciation (e.g. electrochemistry). The first results reveal a high diversity of known and unknown metal-binding secondary metabolites, such as siderophores, and allow us to get a better understanding of the role of chelating agents for trace metal bioavailability and biogeochemical cycling.