Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Creative Commons Lizenz creative commons licence
Titel (primär) Quality of dissolved organic matter driven by autotrophic and heterotrophic microbial processes in a large river
Autor Kamjunke, N.; Lechtenfeld, O.J.; Herzsprung, P.;
Journal / Serie Water
Erscheinungsjahr 2020
Department SEEFO; FLOEK; ANA;
Band/Volume 12
Heft 6
Sprache englisch;
POF III (gesamt) T32;
Supplements 10.3390/w12061577
Keywords Dissolved organic matter (DOM); Fourier transform-ion cyclotron resonance mass spectroscopy (FT-ICR MS); phytoplankton; bacteria; bacterial production
UFZ Querschnittsthemen ProVIS;
Abstract Rivers are regarded as important sites for processing of dissolved organic matter (DOM) from terrestrial sources on its way to the ocean. However, little is known about the longitudinal change of DOM molecular composition in large rivers. Here we performed a Lagrangian sampling in the lower part of the Middle Elbe at low discharge conditions to test how DOM composition changes along the river stretch and how this is related to microbial processes. The concentration of dissolved organic carbon and fluorescence indices showed only subtle longitudinal differences. In contrast, ultra-high-resolution mass spectrometry analysis of riverine DOM detected pronounced changes in molecular composition. Also, chlorophyll a concentration, bacterial abundance, and bacterial production all increased downstream. The three microbial parameters were positively related to intensities of CHO and CHNO molecular formulas with high hydrogen/carbon and low oxygen/carbon ratios but negatively to several CHOS surfactants. To disentangle the role of autotrophic and heterotrophic processes, we developed a new approach and compared slopes from linear regression of DOM compound intensities versus chlorophyll a concentration and bacteria abundance. As a result, most of the positive related DOM compounds were produced by bacteria. In conclusion, longitudinal changes of river DOM seemed to be largely driven by microbial processes.
ID 23174
dauerhafte UFZ-Verlinkung
Kamjunke, N., Lechtenfeld, O.J., Herzsprung, P. (2020):
Quality of dissolved organic matter driven by autotrophic and heterotrophic microbial processes in a large river
Water 12 (6), art. 1577