“Whoa! It's like Spotify but for academic articles.”

Instant Access to Thousands of Journals for just $40/month

Get 2 Weeks Free

Competition for inorganic carbon between photosynthesis and calcification in the symbiont-bearing foraminifer Amphistegina lobifera



227 103 103 2 2 B. ter Kuile J. Erez E. Padan The Interuniversity Institute of Eilat The Hebrew University of Jerusalem P.O. Box 469 88103 Eilat Israel Department of Geology The Hebrew University of Jerusalem 91904 Jerusalem Israel The Division of Microbial and Molecular Ecology, Institute of Life Sciences The Hebrew University of Jerusalem 91904 Jerusalem Israel Unit for Tropical Diseases The International Institute for Cellular and Molecular Pathology Avenue Hippocrate 74.39 B-1200 Brussels Belgium Abstract The processes of photosynthesis and calcification in the symbiont-bearing foraminifer Amphistegina lobifera compete for inorganic carbon (Ci). This conclusion is based on kinetic carbon uptake experiments performed in spring 1987 on specimens from the Gulf of Eilat, Red Sea, that were preincubated in Ci-free seawater in order to empty their internal carbon pools. Photosynthetic rates at 0.8 and 2.2 m M external Ci concentration were initially high and decreased with time while calcification rates started low and increased with time. At Ci=4.2 m M , when inward diffusion of Ci is not rate limiting, both rates were high from the beginning of the experiment. Calcification rates of specimens incubated with 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), to inhibit photosynthesis, were high and constant at all Ci levels. Addition of carbonic anhydrase (CA) to the medium, which catalyses the conversion of HCO 3 - to CO 2 , stimulated photosynthesis but inhibited calcification, probably because it caused the collapse of the internal Ci pool for calcification. Attempts to measure natural CA activity in the foraminifera gave negative results. These observations cannot be explained by models featuring mutual enhancement of photosynthesis and calcification, but instead suggest competition for Ci between these two processes.



Marine BiologySpringer Journals

Published: Jun 1, 1989

DOI: 10.1007/BF00543355

Free Preview of First Page

Loading next page...

You're reading a free preview. Subscribe to read the entire article.

And millions more from thousands of peer-reviewed journals, for just $40/month

Get 2 Weeks Free

To be the best researcher, you need access to the best research

  • With DeepDyve, you can stop worrying about how much articles cost, or if it's too much hassle to order — it's all at your fingertips. Your research is important and deserves the top content.
  • Read from thousands of the leading scholarly journals from Springer, Elsevier, Nature, IEEE, Wiley-Blackwell and more.
  • All the latest content is available, no embargo periods.