Excretion of glycolic acid by algae during photosynthesis.

Although pure cultures of algae, in nutrient solution, have been used extensively in research on photosynthesis, the excretion of products into the medium has not been reported, despite their possible importance in the physiology and biochemistry of such cultures. The present investigation with the Cl4 tracer has revealed a significant, and apparently functional, secretion of glycolic acid by Chlorella into the growth medium under aerobic conditions, concurrent with COS uptake during photosynthesis. In nutrient solutions, below about pH 4.5, Chlorella loses other cell constituents, particularly sucrose.