Metabolism in the protozoon Allogromia laticollaris Arnold

The foraminiferan Allogramia laticollaris, deprived of its natural food, Chlorella, incorporated and metabolized D-glucose added to culture fluid; L-glucose and inulin were not taken up. Fructose 6-phosphate and ATP were also incorporated, probably in a non-degraded form, and metabolized. Equal distribution of radioactivity of [gamma-32P]-ATP added to the medium was observed within 10 min. Intracellular glucose concentrations, and rates of respiration, glucose phosphorylation, and glycolysis were determined. Glucose utilization was stimulated with increasing concentrations of glucose, whereas respiration remained constant. The respiratory quotient increased in accordance with the higher contribution of glucose to energy supply. A. laticollaris can, then, be used for experimental studies of substrate utilization of a synthetic medium.