Metabolic shifts in hypersaline microbial mats upon addition of organic substrates

Stefan Grötzschel*, Raeid M.M. Abed, Dirk De Beer

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


The responses of hypersaline microbial mats to the addition of acetate, glycolate or glucose were investigated using oxygen, pH and sulphide microsensors. Changes in community structure were investigated with molecular techniques. Acetate addition inhibited respiration in the photic zone, stimulated respiration in the aphotic zone and had no effect on gross photosynthesis. Glycolate addition strongly increased both respiration and gross photosynthesis in the photic zone. Thus, glycolate and acetate were probably consumed in those regions of the mat where these substrates are usually formed. Moreover, photosynthesis was only stimulated by increased respiration and concomitant CO2 production in the photic zone which indicates that the photosynthetic and respiratory populations must be present in close proximity to each other. Glucose addition had an unexpected negative effect on the microbial population, strongly inhibiting both respiration and gross photosynthesis within hours. After four days, oxygen profiles in the light were equal to those measured in the dark. After replacing the water phase with unamended water, photosynthesis and respiration recovered within a week. None of the physiological changes were accompanied by detectable shifts in the cyanobacterial or the overall microbial community. The mechanism of inhibition of photosynthesis by glucose requires further investigation.

Original languageEnglish
Pages (from-to)683-695
Number of pages13
JournalEnvironmental Microbiology
Issue number11
Publication statusPublished - Nov 1 2002
Externally publishedYes

ASJC Scopus subject areas

  • Microbiology
  • Ecology, Evolution, Behavior and Systematics


Dive into the research topics of 'Metabolic shifts in hypersaline microbial mats upon addition of organic substrates'. Together they form a unique fingerprint.

Cite this