Kinetics of polyglucose breakdown in Chlorobium

Washed cells of Chlorobium limicola f. thiosulfatophilum photoassimilate CO₂ and acetate into polyglucose, which is laid down within the cells as rosette-like granules. When the cells are incubated in the dark, the polyglucose is broken down. Experiments using electron microscopy and labelling with ¹⁴C-acetate have revealed that degradation of polyglucose occurs in such a way that all the granules are subject to degradation simultaneously and the polyglucose which has been formed most recently in the light, becomes metabolized in the dark first.