抄録
The rate of respiration of the root-nodules, deta-ched from roots, decreased with decreasing partial pressure of oxygen and increased somewhat in pure oxygen than in the air. But the rate of respiration of the bacteria centrifuged from nodules was not affected by decreasing percentage of oxygen. The concentration of KCN at the half inhibition of respiration was about 3×10^<-4> mol for centrifuged bacteria from soybean and vetch-nodules, and 5×10^<-5> mol for pea-bacteria from laboratory culture. For soybean nodules, 10^<-2> mol was needed for half inhibition, due to the probable inhibition of KCN penetration into the interior of the nodules. CO inhibitted the respiration of artificially cultured root-nodule bacteria about half or more in the atmosphere of 95% CO and 5% O_2,whereas the centrifuged bacteria from nodules was innert to CO even in that concentration.
