Effects of Glycollate on the Growth of a PlanktonicChlorella

Abstract

The duration of the lag phase in cultures of a planktonic strain of Chlorella pyrenoidosa growing from small inocula under conditions of light limitation was shortened by the addition of 1 mg 1^–1 of glycollate to the medium. Of eight related compounds tested, none, with the possible exception of lactate, had a similar effect. Addition of 1 mg 1^–1 of glycollate also considerably increased the relative growth-rate of the alga at low (500 lux) but not at higher light intensities. This effect was not, however, specific to glycollate. Concentrations of glycollate (20 mg 1^–1) higher than those normally produced in cultures by excretion had an inhibitory effect on growth.