[Studies on the uptake of glycolate by Chlorogonium]

The alga Chlorogonium was cultured either heterotrophically or autotrophically under different partial pressures of CO2 by aerating with pure air of air enriched with 2% CO2. Cells were harvested in the logarithmic phase, transferred to phosphate buffer containing 0.01 M 1C(14)-glycolate and incubated with shaking in the dark. Under these conditions the rate of glycolate uptake was higher when the cells had been grown in the light. Cells grown in the light at the lower CO2-concentration took up more glycolate than those grown with 2% CO2. Approximately 90% of the radioactivity taken up with the glycolate was released as CO2. The radioactivity remaining in the algae was somewhat higher in those cells which had been cultured heterotrophically or autotrophically under air than in cells grown autotrophically under air enriched with 2% CO2.Addition of glycolate increased the uptake of oxygen by the cells. The consumption of the oxygen was quantitatively correlated to the uptake of glycolate.