A Mutant of Rhizobium Japonicum 110 with Elevated Nif Activity in Free-Living Culture
The enhancement of biological nitrogen fixation in the legume-Rhizobium symbiosis involves selection strategies at both the plant and symbiont level to identify and define traits suitable for improving the symbiosis. One of the major advances at the symbiont level was the identification of the hydrogen uptake (Hup) enzyme system as being important in the overall energy efficiency of nitrogen fixation (Schubert and Evans, 1976; also this volume). Rhizobium strains that possess the uptake hydrogenase are able to reutilize some of the hydrogen evolved from nitrogenase (Schubert and Evans, 1976) and thus regenerate ATP (Emerich et al., 1979). This is important in a system which has such a high energy (ATP) demand for biological nitrogen fixation (Andersen and Shanmugam, 1977).
KeywordsNitrogen Fixation Nitrate Reductase Activity Rhizobium Strain Hydrogenase Activity Potassium Chlorate
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