[Inhibitory analysis of the respiration of bacteroids from the nodules of yellow lupine].

Oxygen uptake and reduction of C2H2 by bacteroids was found to be inhibited by low concentrations of cyanide and azide. However, oxygen uptake was not completely suppressed even by 10(-3) M KCN. Cyanide-resistant respiration was not inhibited by salicyl-hydroxamic acid, and seemed to be accomplished at the account of autoxidable flavo-proteins. A small light-reversible inhibition of respiration by carbon monoxide was found only in the bacteroids with a high rate of nitrogen fixation. Rotenone, antimycin A, and tenoyltrifluoroacetone inhibited oxygen uptake and methylene reduction. Nitrogen fixation, but not respiration, was inhibited by 2,4-dinitrophenol. An electron-transport chain coupled with phosphorylation is supposed to be built into the membranes of the bacteroids. The activity of peroxidase and cytochrome peroxidase was demonstrated in the bacteroids.