Abstract
Photorespiration has been assayed in a variety of marine macroalgae by the Warburg oxygen inhibitory effect and the percentage14C-labeling of glycine and serine. It was found that particularly the members of the brown macroalgae examined, such asFucus andLaminaria (Phaeophyceae), show a rather weak response to high O2 partial pressure. This observation is attributed to the appreciably high potential for β-carboxylation via PEP-carboxykinase, generally occurring in brown seaweeds.