Program

 
Special Session 9: Microbial ecological processes and marine carbon cycle
 

 
 
1050
Picocyanobacteria and deep-ocean fluorescent dissolved organic matter share similar optical properties
Tuesday 10th @ 1050-1110
Room 1
Michael Gonsior* , University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, USA.
Zhao Zhao, State Key Lab for Marine Environmental Science, Institution of Marine Microbes and Ecosphere, Xiamen University, China.
Norbert Hertkorn, Helmholtz Zentrum Muenchen, Research Unit Analytical BioGeoChemistry, Neuherberg, Germany
Philippe Schmitt-Kopplin, Helmholtz Zentrum Muenchen, Research Unit Analytical BioGeoChemistry, Neuherberg, Germany Technische Universität MĘ╣nchen, Analytical Food Chemistry, Freising-Weihenstephan, Germany
Xiaoting Fang, The Hong Kong University of Science and Technology, Environmental Science Programs, Hong Kong, China
Qinglu Zeng, The Hong Kong University of Science and Technology, Division of Life Science, Hong Kong, China
Nianzhi Jiao, University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, USA.
Feng Chen, University of Maryland Center for Environmental Science, Institute of Marine and Environmental Technology, USA.
Presenter Email: gonsior@umces.edu

The origin and fate of marine chromophoric dissolved organic matter (CDOM) and its subset of fluorescent CDOM (FDOM) has been and continuous to be debated. Recent studies suggested in situ sources, rather than remnants of terrestrially-derived DOM. However, no convincing marine sources have been thus far put forward to explain in detail the observed absorbance and fluorescent pattern. Here we show that picocyanobacteria, namely Prochlorococcus and Synechococcus strains, released CDOM and FDOM that were highly similar to the observed pattern in the deep ocean. We conducted photochemical and microbial degradation experiments, ultrahigh resolution mass spectrometry, NMR, and apparent fluorescent quantum yield measurements and results were conclusive and supported the hypothesis that picocyanobacteria have the potential to be a major source of marine CDOM.