INHIBITION OF RESPIRATION DURING PHOTOSYNTHESIS BY SOME ALGAE

Abstract

An infrared CO₂ analyzer was used to measure production and assimilation of CO₂ by 11 marine or freshwater algae in acidic media. Considerable differences among the algae were found in the concentration of CO₂ required to saturate photosynthesis and in the compensation concentration of CO₂. High compensation values were always lowered by lowering the O₂ concentration, even to concentrations which did not reduce respiration in the dark. It was concluded that respiration was inhibited during photosynthesis. In four of the algae, respiration was replaced by a different process of CO₂ production during photosynthesis.