Woods Hole Oceanographic Institution

Elizabeth B Kujawinski Behn

»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

E. B. Kujawinski, K. Longnecker, N. V. Blough, R. Del Vecchio, L. Finlay, J. B. Kitner and S. J. Giovannoni, Identification of possible source markers in marine dissolved organic matter using ultrahigh resolution electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry, Geochimica et Cosmochimica Acta 73: 4384-4399, 2009

Marine dissolved organic matter (DOM) is one of the most heterogeneous and largest pools of reactive carbon on earth, rivaling in mass the carbon in atmospheric carbon dioxide. Nevertheless, the molecular-level composition of marine DOM has eluded detailed description, impeding inquiry into the specific mechanisms that add or remove compounds from the DOM pool. Here we describe the molecular-level composition of C18-extracted DOM along an east-west transect of the North Atlantic Ocean. We examine the changes in DOM composition along this transect with ultrahigh resolution mass spectrometry and multivariate statistics. We use indicator species analysis (ISA) to identify possible source markers for photochemical degradation and heterotrophic bacterial metabolism. The inclusion of ISA in statistical evaluation of DOM mass spectral data allows investigators to determine the m/z values associated with significant changes in DOM composition. With this technique, we observe indicator m/z values in estuarine water that may represent components of terrestrially-derived chromophoric DOM subject to photo-chemical degradation. We also observe a unique set of m/z values in surface seawater and show that many of these are present in pure cultures of the marine a-proteobacterium Candidatus Pelagibacter ubique when grown in natural seawater.   These findings indicate that a complex balance of abiotic and biotic processes controls the molecular composition of marine DOM to produce signatures that are characteristic of different environments. You can access the journal article at GCA here.

FILE » Article text

» Figure 1

» Figure 2

» Figure 3

» Figure 4

» Figure 5

» Electronic annex

© Woods Hole Oceanographic Institution
All rights reserved