[Cytochrome composition and content of Citrobacter freundii].

Citrobacter freundii, strain 62, produces considerable amounts of cytochromes c and b when it grows in media with different carbon compounds under both aerobic anc anaerobic conditions. The content of cytochromes c increases under anaerobic conditions, particularly in the presence of formate or DMSO, and under aerobic conditions if formate is added. In contrast, the amount of cytochromes b decreased when the culture is grown in media with formate under anaerobic conditions. Cytochrome o is principal terminal oxidase in C. freundii. Under certain growth conditions, the microorganism, just as E. coli, produced also cytochromes a and d.