[The Influence of the Permeability of the Cell Membrane on TMPD Oxydase Activity (author's transl)].

26 bacterial strains representing a variety of both Gram-negative and Gram-postive groups were investigated for their N,N,N',N'-Tetramethyl-1, 4-phenylendiamin (TMPD) oxidase activities and cytochrome contents. The oxidase activites of colonies were examined by dropping the reagent on agar surface colonies. Intact and sonicated cells were tested by recording the oxidation of the TMPD reagent at 546 nm after addition to the cell suspensions. Cytochromes were determined by recording the difference spectra (KBH4-reduced minus H2O2-oxidized) between 400nm and 630 nm. After sonication of intact cells of the "oxidase negative" Enterobacteriaceae except the Proteus strains, the Flavobacterium strains, Streptococcus faecalis, Xanthomonas phaseoli, and the Acinetobacter strains investigated oxidase activities were observed and the oxidase activities of the "oxidase positive" Bacillus and Micrococcus strains and Haemophilus influenzae were increases. These observations show that negative oxidase reactions exhibited by bacterial colonies may not only be due to the lack of the oxidizing enzyme system itself but also to impermeability of the cell membrane for the TMPD reagent. The TMPD oxidase activity could not be correlated to the cytochrome contents of the cells.