The Effect of Carbon Dioxide Concentratioin, light Intensity and Isonicotinyl Hydrazide on the Photosynthetic Production of Glycollic Acid by Chlorella

Glycollic acid production by Chlorella was measured by colorimetricdetermination of the acid excreted into the medium. It was foundthat glycollic acid production showed a maximum at a low concentrationof carbon dioxide but tended toward zero as the rate of photosynthesisapproached carbon dioxide saturation. Glycollic acid productionbecame measurable at light intensities approaching that requiredto saturate photosynthesis and increased steadily with furtherincrease in intensity. Treatment with isonicotinyl hydrazideresulted in an approximately threefold stimulation of glycollicacid concentration over the range of conditions used. It issuggested that the precursor of glycollic acid is ribulose diphosphate,and that isonicotinyl hydrazide acts by inhibiting the furthermetabolism of glycollic acid.