Paramylon Synthesis by Euglena gracilis Photoheterotrophically Grown Under Low O sub(2) Pressure

Special culture conditions for E. gracilis Z and ZR are described. They induce interactions between the chloroplast and mitochondrial metabolisms leading to paramylon synthesis. When grown in continous light under pure nitrogen and in the presence of lactate as the sole carbon source, sugar synthesi...

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Bibliographic Details
Published in:Planta 1981-01, Vol.153 (1), p.6-13
Main Authors: Calvayrac, R, Laval-Martin, D, Briand, J, Farineau, J
Format: Article
Language:English
Subjects:
Euglena gracilis
Freshwater
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Summary:Special culture conditions for E. gracilis Z and ZR are described. They induce interactions between the chloroplast and mitochondrial metabolisms leading to paramylon synthesis. When grown in continous light under pure nitrogen and in the presence of lactate as the sole carbon source, sugar synthesis occurs during the first 24 h of culture with the participation of both mitochondria (using lactate) and of chloroplasts (fixing CO sub(2) from lactate decarboxylation). The activities of ribulose bisphosphate carboxyalse, phosphoenolpyruvate carboxylase, and phosphoenolpyruvate carboxykinase are very high and mitochondria and chloroplasts develop then a common network of visicles in which paramylon grains can be seen. Electron micrographs demonstrate membrane continuity between the two types of organelles. Occasionally the mitochondrial matrix and the chloroplast stroma are separated by only a unit membrane.
ISSN:0032-0935