In:
Canadian Journal of Botany, Canadian Science Publishing, Vol. 76, No. 6 ( 1998-06-01), p. 949-953
Abstract:
The unexpected finding that certain major marine photosynthetic microorganisms can serve as a source of CO 2 rather than a sink emerged during measurements of inorganic carbon fluxes associated with the CO 2 -concentrating mechanism. During steady-state photosynthesis, CO 2 was evolved at sustained rates up to 5-fold that of photosynthesis; the steady-state external CO 2 concentration reached was significantly higher than that at CO 2 -HCO 3 - equilibrium. The evolved CO 2 originated from HCO 3 - taken up and intracellularly converted to CO 2 in a light-dependent process. Our results bear implications for carbon cycling in the marine environment; the use of naturally-observed stable carbon isotope fractionations as paleobarometer and productivity probe; and for intracellular energy balance and pH regulation.Key words: carbonic anhydrase, CO 2 evolution, cyanobacteria, photosynthesis, Synechococcus.
Type of Medium:
Online Resource
ISSN:
0008-4026
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1998
detail.hit.zdb_id:
218116-2
detail.hit.zdb_id:
1481926-0
SSG:
12
