Abstract
Oxygen consumption by six species of nodule bacteria were measured in micro-manometers by Warburg technic. The rate of oxygen consumed by 10 milligrammes of moist bacterial cell of Rh. leguminosarum and Rh. meliloti in yeast water mannitol medium were increased more highly than that of Rh. lupini, Rh. jeponicum and "genge" bacteria, while Rh. trifolii consumed oxygen in the lowest rate. The rate of oxygen consumed by one million of bacteria was also special for these species : namely Rh. meliloti and Rh. trifolii. were the most energetic consumers and Rh. lupini was the weakest. To find the effects of pentose and hexose upon the oxygen consumption by Rhizobia, xylose, arabinose, glucose and fructose were used as carbon sources. However, there was no specific relation between the extent of oxygen consumed and the composition of the carbohydrates. The oxygen tension had little influences upon the rate of oxygen consumption by Rh. japonicum and Rh. lupini. But it was thought that Rh. meliloti consumed oxygen in the highest rate under oxygen pressure similar to air, and that Rh. trifolii prefered more reduced pressure.
