%0 Journal Article %A Willison, J. C. %A John, P. %T Mutants of Paracoccus denitrificans Deficient in c-type Cytochromes %D 1979 %J Microbiology, %V 115 %N 2 %P 443-450 %@ 1465-2080 %R https://doi.org/10.1099/00221287-115-2-443 %I Microbiology Society, %X Eight mutants of Paracoccus denitrificans deficient in c-type cytochrome were detected by their inability to catalyse the conversion of α-naphthol plus dimethyl-p-phenylenediamine to indophenol. From the properties of two of these mutants which completely lacked spectrophotometrically detectable c-type cytochrome, evidence was provided for the presence of a respiratory pathway which terminates in a cytochrome o-like oxidase. The presence of this pathway allows mutants lacking c-type cytochrome to grow aerobically, and also explains many of the non-mitochondrial features of the aerobic respiratory chain of the wild-type. None of the mutants had significantly lower levels of b-type cytochromes compared with the parental strain, but two mutants were deficient in cytochrome aa 3. All of the mutants could reduce nitrate, but four of them were unable to denitrify and these showed poor growth with nitrate as added terminal electron acceptor. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-115-2-443