Reductant and energy level of bacteroids of Rhizobium leguminosarum

Low redox potential electron carriers such as benzyl viologen and NAD⁺ were reduced by bacteroids prepared from nodules of pea inoculated with hup^{+ R. leguminosarum} strain Vp1, whereas, the bacteroids of plasmid cured hup^- derivative Vm1 did not exhibit the reducing activity. The bacteroids prepared from nodules of hup⁺ strain Vp1 at 46d stage, where nitrogenase activity was maximum, exhibited 1.5-fold higher levels of NADH/NADPH, two-fold higher levels of ATP while the level of ADP and AMP were lower as compared to the bacteroids of hup^- strain Vm1. Also the level of adenylate energy charge in ^hup+ bacteroids was 29% higher than the hup^- bacteroids.