Sw. Marcelli et al., THE RESPIRATORY-CHAIN OF HELICOBACTER-PYLORI - IDENTIFICATION OF CYTOCHROMES AND THE EFFECTS OF OXYGEN ON CYTOCHROME AND MENAQUINONE LEVELS, FEMS microbiology letters, 138(1), 1996, pp. 59-64
The quinone and cytochrome components of the respiratory chain of the
microaerophilic bacterium Helicobacter pylori have been investigated.
The major isoprenoid quinone was menaquinone-6, with traces of menaqui
none-l; no methyl-substituted or unusual menaquinone species were foun
d. Cell yield was highest after growth at 10% (v/v) oxygen and menaqui
none levels (per dry cell mass) were maximal at 5-10% (v/v) oxygen. He
licobacter pylori cells and membranes contained b- and c-type cytochro
mes, but not terminal oxidases of the a- or d-types, as judged by redu
ced minus oxidised difference spectra. Spectra consistent with the pre
sence of a GO-binding terminal oxidase of the cytochrome b- or o-type
were obtained. The soluble fraction from disrupted cells also containe
d cytochrome c. There were no significant qualitative differences in t
he cytochrome complements of cells grown at oxygen concentrations in t
he range 2-15% (v/v) but putative oxidases were highest in cells grown
at 5-10% (v/v) oxygen.