[Studies on the connection between nutrition and enzyme activity in several green algae]

In several algae (Chlamydobotrys stellata, Chlamydomonas mundana, Chlorella vulgaris, Chlorogonium elongatum, Euglena gracilis, Scenedesmus obliquus) the influence of the nutrition either with carbon dioxide or with acetate on the activities of enzymes typical for the Calvin- or the glyoxylate-cycle has been studied. The activities of the NADP-glyceraldehyde-dehydrogenase and the Ls-isocitrate-lyase were compared with the actual role of indirect (via photosynthetic assimilation of carbon dioxide released from acetate by oxydation) and direct (via the glyoxylatecycle) photo-assimilation of carbon from acetate in the light dependent synthesis of carbohydrates. From the results obtained during this investigation it can be concluded that which pathway of carbon from acetate to carbohydrates predominates in the light depends mainly on the autotrophic or photoheterotrophic nature of the organisms, in spite of the fact that in algae of the autotrophic type the nutrition with acetate also induces the activity of enzymes necessary for the direct assimilation of acetate.