Abstract
P. cytochrome oxidase could be obtained from Pseudomonas aeruginosa cells grown in the presence of KNO3, regardless of whether cultures were aerobic or anaerobic. Thus the essential factor for the biosynthesis of P. cytochrome oxidase appears to be the pre-sence of KNO3. P. cytochrome oxidase is apparently an adaptive enzyme, and seems to act as the only nitrite reductase in this organism.
It is suggested that cytochrome oxidase in the cells grown aerobically in the absence of KNO3 differs from either mammalian cytochrome a or P. cytochrome oxidase.
The authors wish to express their thanks to Dr. K. Kusai(Amagasaki Factory, Nagase & Co., Amaga-saki-shi) for mass-culture of the bacteria. Thanks also due to Dr. S. Takemori for help in preparing cytochrome a.
