The Earth Institute's Lamont-Doherty Earth Observatory Earth Science Colloquium presents "Probing the Molecular Basis For Microbe-Dissolved Organic Matter Interactions in the Marine Environment", with Elizabeth Kujawinski, Associate Scientist w/ Tenure, Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution. Open to the Public.
Host: Sonya Dyhrman, Associate Professor, Biology and Paleo Environment, LDEO.
Probing The Molecular Basis For Microbe-Dissolved Organic Matter Interactions In The Marine Environment
Dissolved organic matter (DOM) in marine systems is a
large, heterogeneous pool of reduced carbon, whose fate affects all aspects of
the global carbon cycle. Molecules within DOM are produced, removed and altered
by microbial consortia in all depth regimes of the ocean. These molecular-level
processes culminate in the observed fluxes among OM pools in the ocean and of
paramount importance in global carbon dynamics. Recent analytical advances
allow researchers to probe the composition of DOM and to probe the interactions
between DOM and microbes at the molecular level. With these novel tools, we are
able to quantify known compounds and discover new markers for biotic processes.
My laboratory has focused recent efforts on the examination of DOM in
laboratory cultures of representative marine microbes and in field samples from
Line P in the eastern Pacific Ocean. We employ three mass spectrometric
techniques designed to detect, identify and quantify known and unknown
compounds within organic matter mixtures. We explore the sources of DOM with
culture-based investigations of metabolites exuded by phytoplankton and
heterotrophic bacteria. We further examine the shifts in DOM composition and cellular
metabolites from the coast to the open ocean as well as down the depth profile
at selected locations. Through the integration of our complementary datasets,
we are developing a more comprehensive view of the role microbes may play in DOM
composition and modification. These data provide important chemical contexts
for an emerging systems-biology view of the ocean.