BIOLOGICAL NITROGEN FIXATION. THE EFFECT OF IRRADIATED NITROGEN GAS ON NITROGEN FIXATION BY AZOTOBACTER

Five articles concerned with the effect of nitrogen gas on nitrogen fixation by Azotobacter are reviewed. Particular attention is given to culture media used, methods of analysis, and calculations. Results are summarized for work on: production, detection, and measurement of gas ions; nitrogen fixation in batch cultures of A. vinelandii; nitrogen fixation in batch cultures of different species and strains of Azotobacter; nitrogen fixation in continuous cultures of A. vinelandii; and enzymatic studies. It is concluded that the gas ions responsible for the increased nitrogen fixation observed in Azotobacter fed irradiated N gas are likely molecular N gas ions. (H.M.G.)