FURTHER EVIDENCE OF THE EXISTENCE OF MITOCHONDRIA IN BACTERIA

Abstract

Cytoplasmic granules in cells of the wild-type of Saccharomyces cerevisiae and in cells of Escherichia coli, Micrococcus cryophilus, and Bacillus megatherium are shown to give indicator reactions for oxidative-reductive enzymes characteristic of the aerobic respiratory activities of mitochondria. In E. coli and in M. cryophilus, as previously in mycobacteria, these indicator reactions are shown to be localized in electron-scattering spheroidal to ellipsoidal particles. Such particles are not demonstrated by nuclear staining pro-cedures, nor do the nuclei react to mitochondrial indicators. Electron-scattering particles morphologically similar to the pre-ceding ones, but variously interpreted, have been demonstrated in a variety of bacteria, treponemes, and rickettsiae. It is suggested that certain identification of the nature and function of such particles will require application of a series of mitochondrial indicator reactions and specific nuclear stains, and should be confirmed by assay of enzymatic activities.