Evidence of de novo synthesis of maltose excreted by the endosymbiotic Chlorella from Paramecium bursaria.

The endosymbiotic Chlorella sp. from Paramecium bursaria excretes maltose both in the light and in the dark. Experiments on photosynthetic (14)CO2 fixation and (14)CO2 pulse-chase experiments show that maltose is synthesized in the light directly from compounds of the Calvin cycle, whereas in the dark it results from starch degradation.