Blue Light Induction of Carbonic Anhydrase Activity in Chlamydomonas reinhardtii

Abstract
Blue light was specifically required for the induction of carbonic anhydrase (CA) activity in Chlamydomonas reinhardtii. The enhancing effect of blue light (460 nm) was saturated at energy fluence rate as low as 0.6-0.8 W/m2. The wavelength dependency curve had a peak at 460 nm with no effect at wavelengths above 510 nm, thus showing the strong similarities to other blue light responses in microalgae. CA induction was strongly inhibited by UV irradiation at 280 nm. Experiments with the flavin quencher, potassium iodide, suggested that flavin is somehow involved in CA induction.