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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 4034

J.G. Peak and M.J. Peak; Regulation by Ammonium of Variation in Heterotrophic CO2 Fixation by Euglena gracilis During Growth Cycles. J.Protozool. 24(3):441-444, 1977

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Heterotrophic (dark) CO2 fixation by Euglena gracilis strain Z varies with phase of batch growth and mode of nutrition. Increase in the fixation during growth cycles correlate closely with the depletion of exogenous NH4+ from the medium during growth. It is demonstrated that exogenous NH4+ regulates a component of heterotrophic CO2 fixation and that another component is independent of NH4+. This is true for cells grown heterotrophically (glucose, dark), autotrophically (CO2, light) and for a permanently bleached strain (E. gracilis SB3). Some kinetics of the NH4+ regulation are presented.