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Tracing the production and degradation of autochthonous fractions of dissolved organic matter by fluorescence analysis
Author(s) -
Stedmon Colin A.,
Markager Stiig
Publication year - 2005
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2005.50.5.1415
Subject(s) - dissolved organic carbon , environmental chemistry , organic matter , mesocosm , phytoplankton , chemistry , plankton , fluorescence , nutrient , fluorescence spectroscopy , microbial biodegradation , microorganism , ecology , biology , bacteria , physics , organic chemistry , quantum mechanics , genetics
We present the results of a mesocosm experiment investigating the production and utilization of autochthonous dissolved organic matter (DOM) by the plankton community under different inorganic nutrient regimes. Fluorescence spectroscopy combined with parallel factor analysis was applied to study the dynamics of autochthonous DOM. Seven independent fluorescent fractions were identified, differing in their spectral characteristics, production rates, and sensitivity to photochemical and microbial degradation processes. Five different humic fractions, a marine protein, and a peptide fluorescence were found. The five humic fractions were produced microbially, with the greatest production occurring under combined Si‐ and P‐limiting conditions. The two proteinaceous fractions were produced during exponential growth of phytoplankton, irrespective of biomass composition. Photodegradation was an important sink for the microbially derived humic material, and the marine protein material was susceptible to both photoand microbial degradation.