This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Peak, J. G. Articles by Ting, I. P. Search for Related Content PubMed PubMed Citation Articles by Peak, J. G. Articles by Ting, I. P. Agricola Articles by Peak, J. G. Articles by Ting, I. P.

Short Communication

Heterotrophic Carbon Dioxide Fixation Products of Euglena

EFFECTS OF AMMONIUM ¹

Irwin P. Ting

Department of Zoology, Rhodes University, Grahamstown 6140 South Africa, Department of Botany and Plant Sciences, University of California, Riverside, California 92521

The metabolic products of heterotrophic (dark) CO₂ fixation by Euglena gracilis Klebs strain Z Pringsheim were separated and identified. They consisted of amino acids, phosphorylated compounds, tricarboxylic acid cycle intermediates, and nucleotides. Exposure of the cells to NH₄⁺ after a period of NH₄⁺ deprivation stimulated heterotrophic CO₂ fixation almost 4-fold, modifying the spectrum of the fixation products. In particular, the NH₄⁺ treatment stimulated fixation of CO₂ into glutamine, glycine, alanine, and serine.