Correlation between Carbonic Anhydrase Activity and Inorganic Carbon Internal Pool in Strain Synechocystis PCC 6174.

Existence of an internal carbonic anhydrase was demonstrated in the cyanobacterium Synechocystis PCC 6714. The enzyme, present at a low specific activity, was inducible by limitation in inorganic carbon and inhibited both in vivo and in vitro by acetazolamide. The internal inorganic carbon pool as determined by mass spectrometry, was similarly modulated by the actual inorganic carbon growth regime; its building up was also sensitive to acetazolamide. A possible role of carbonic anhydrase in inorganic carbon metabolism regulation through the control of the dimension and nature of the inorganic carbon pool is discussed.