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Woods Hole Oceanographic Institution

Elizabeth B. Kujawinski

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Publications
»Using stable isotope probing to characterize differences between free-living and sediment-associated microorganisms in the subsurface.
»DOM in Lake Superior
»Deepwater Horizon hydrocarbons in the marine environment
»Microbes and marine DOM, Ann. Rev. Mar. Sci. 2011
»Greenland ice sheet outlet glacier: Insights from a new isotope-mixing model
»Groundwater DOM, GCA 2011
»Dispersants & DWH, ES&T 2011
»FT-MS variability in DOM, Org Geochem 2010
»Predatory Flavobacteria, FEMS Microb Ecol 2010
»Greenland Ice Sheet DOM, GCA 2010
»Protozoa and bacteria in aquifers, FEMS Microb Ecol, 2009
»Source markers in DOM, GCA 2009
»Automated data analysis, Anal. Chem. 2006
»Marine DOM and ESI FT-ICR MS; Marine Chem 2004
»DOM extraction by C18; Org. Geochem. 2003
»Black carbon by ESI FT-ICR MS; ES&T 2004
»ESI FT-ICR MS review; Env. Forensics 2002
»Marine protozoan surfactants; Marine Chem. 2002
»ESI MS and NOM; Org. Geochem. 2002
»ESI FT-ICR MS & humic acids; Anal. Chem. 2002
»Protozoan DOM & PCBs; ES&T 2001
»Protozoa & Fe, Th, C; Aquat. Microb. Ecol. 2001
»PCB uptake by protozoa; AEM 2000


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K. A. Barbeau, E. B. Kujawinski, and J. W. Moffett, Remineralization and recycling of iron, thorium and organic carbon by heterotrophic marine protists in laboratory culture, Aquatic Microbial Ecology 24: 69-81, 2001

To characterize trace metal cycling in marine systems as mediated by heterotrophic protists, we have conducted a series of laboratory experiments in two-organism model systems consisting of bacteria and protistan grazers.  Trace metal isotopes (59Fe and 234Th), 14C, and bulk organic carbon measurements were used to follow the chemical transformation of bacterial carbon and associated trace metals by several different grazer species.  Results indicate that grazers were able to cause repartitioning of Th and regeneration of Fe from bacterial prey into the dissolved phase (<0.2 mm), even in particle-rich laboratory cultures. For both Th and Fe, protist grazing led to the formation of relatively stable dissolved and colloidal metal-organic species. Metal/carbon ratios of the particle pool in some model systems with grazers were shown to be significantly altered, indicating a decoupling of trace metal and organic carbon cycling through the grazing process. Different protist species exhibited substantial variation (up to a factor of 10) in their ability to quantitatively remobilize trace metals from bacterial prey. The implications of these findings for trace metal cycling in marine systems are discussed.

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