Carbonic anhydrase activity of Prochloron sp. isolated from an ascidian host

Abstract

The prokaryotic algal symbiont of ascidians, Prochloron sp., was found to exhibit carbonic anhydrase activity which is largely associated with the cell surface. This extracellular carbonic anhydrase activity was inhibited, while the intracellular activity was not affected, by chloride or bromide. Acetazolamide and ethoxyzolamide inhibited carbonic anhydrase activity with I50 values of 7×10-4 and 3×10-4M, respectively. These I50 values are similar to those observed for intracellular carbonic anhydrases of Synechococcus sp. PCC7942, Chlamydomonas reinhardii and spinach.