The Oxidation of 14C-labelled Glucose by Chlorella vulgaris

Abstract

Most of the ¹⁴C added as glucose to carbohydrate-starved cells of Chlorella Vulgaris can be recovered as alcohol-soluble compounds or as polysaccharide. Only 5−I6 per cent., depending on the position of ¹⁴C in the glucose supplied, is released as carbon dioxide. Similar results were obtained with Chlorella pyrenoidosa and Ankistrodesmus. The labelled alcohol-soluble compounds in Chlorella vulgaris include amino-acids, particularly glutamic acid, aspartic acid, and alanine, and, when glucose-I-¹⁴C is metabolized, the amount of ¹⁴C recovered in these amino-acids is about the same as that recovered as carbon dioxide. Degradation of the glucose incorporated into polysaccharide shown that the C₁ and C₆ atoms of glucose rapidly interchange when in the cells. The bearing of these results on attempts to estimate the relative importance of different pathways of glucose breakdown is discussed.