Publication
Title
Seasonal changes in the biochemical fate of carbon fixed by benthic diatoms in intertidal sediments
Author
Abstract
Benthic diatoms are important primary producers in intertidal marine sediments and form the basis of the food web in these ecosystems. In order to investigate the carbon flow within diatom mats, we performed in situ C-13 pulse-chase labeling experiments and followed in detail the biochemical fate of carbon fixed by the diatoms for five consecutive days. These labeling experiments were done at approximately 2-monthly intervals during 1 yr in order to cover seasonal variations. The fixed carbon was recovered in individual carbohydrates including extracellular polymeric substances (EPS), amino acids, fatty acids, and nucleic acid bases. In addition, we assessed a variety of environmental parameters and photosynthetic characteristics. The fixed carbon was initially mainly stored as carbohydrate (glucose) while nitrogen-rich compounds (e.g., amino acids and RNA/DNA) were produced more slowly. During the year, the diatoms distributed the photosynthetically fixed carbon differently among the various carbon pools that were measured. In summer, the diatoms decreased carbon fixation and accumulated relatively more lipid as a storage compound (27% +/- 2% vs. 12% +/- 5% in other seasons). The percentage of fixed carbon that was excreted as EPS was lower in summer compared to other seasons, amounting 9% +/- 4% and 21% +/- 6%, respectively. Hence, it seemed that the physiology of the microphytobenthos was different during summer and caused by higher light intensity and a shift in nitrogen source.
Language
English
Source (journal)
Limnology and oceanography. - Lawrence, Kan.
Publication
Lawrence, Kan. : 2018
ISSN
0024-3590
Volume/pages
63 :2 (2018) , p. 550-569
ISI
000427104700004
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 29.03.2018
Last edited 20.09.2021
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