Cytochrome Composition of Some Strains of Streptomyces

SMITH 1 has discussed the bacterial cytochromes in relation to each other and in comparison with those from yeast and mammalian sources. Her review serves to emphasize the variations existing among the bacteria, and the fact that generalizations concerning the functions of the various cytochromes are difficult to make. Since information concerning even the existence of cytochromes in Streptomycetes is meagre 2 , it was felt that a spectrophotometric survey of the general cytochrome composition of various strains would provide a useful basis for more complete investigations of a physiological nature and contribute to the microbial cytochrome picture in general. Furthermore, the activity of Streptomycetes as prolific producers of antibiotics and as producers of vitamins makes a better understanding of their physiology of considerable interest. In this regard, various investigations have shown that iron is required in media used for antibiotic production by Streptomycetes 3 , and a recent investigation of the effect of trace metals on their growth revealed a striking beneficial effect of iron on each of eight organisms examined 4 . These results and the importance of iron in respiratory pigments suggested the likelihood that cytochromes were present.