Effect of cycloheximide on the process of “glucose-bleaching” in Chlorella protothecoides

The process of bleaching of Chlorella protothecoides induced by the addition of glucose was strongly inhibited by cycloheximide, an inhibitor of protein synthesis, whereas it was suppressed only weakly by chloramphenicol, puromycin and ethionine. When cycloheximide was added simultaneously with glucose at the beginning of die bleaching experiment, no bleaching of algal cells occurred during the subsequent incubation. When it was added after glucose, the bleaching of algal cells proceeded for a period of time as actively as in the control, then gradually ceased. Cycloheximide was found to suppress the uptake of glucose by algal cells, and to severely inhibit the assimilation of glucose into lipids when added at the beginning of the bleaching experiment. These inhibitory effects of cycloheximide are discussed in relation to the induction of “glucose-bleaching” in algal cells.