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Updated: Jun 19, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
THE INFLUENCE OF ROENTGEN RAYS UPON THE NITROGEN FIXATION BY AZOTOBACTER
R M Whelden1, E V Enzmann, C P Haskins
1Biological Laboratories, Harvard University, Cambridge, Massachusetts, and the Haskins Laboratories, New York, New York.
Abstract:
The influence of graded x-ray doses upon nitrogen fixation and respiration by Azotobacter was studied by means of the Warburg method. It was found that nitrogen fixation decreases approximately linearly with increasing x-ray doses. Respiration in contrast is affected only indirectly through some inhibition of cell multiplication. Small doses of x-ray often produce a slight and transient increase in the rate of oxygen uptake.
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