The microaerophilic respiration of Campylobacter mucosalis

Biochim Biophys Acta. 1988 Mar 30;933(1):114-23. doi: 10.1016/0005-2728(88)90061-8.

Abstract

A model is proposed for the respiratory adaptation to falling oxygen concentration during growth of the microaerophilic bacterium Campylobacter mucosalis. During the early stages of growth, the oxidation of formate is a two-stage branched process involving the production of H2O2 followed by its peroxidatic removal. In later stages of growth, at lower oxygen concentrations, the predominant electron flow is linear to a membrane-bound cytochrome-c oxidase which reduces O2 directly to H2O. Several components of this model have been investigated. H2O2 was produced during formate oxidation and accumulated when electron transfer to the cytochrome-c peroxidase was inhibited. A cytochrome c-553, of the Class 1 types, was purified and shown to be the specific electron donor to both the peroxidase and the membrane-bound oxidase. The levels of this cytochrome c and of the peroxidase were higher in cells harvested early in growth. In later stages of growth, the activity of the membrane-bound oxidase increased. Proton pumping across the membrane was detected with either H2O2 or oxygen as terminal electron acceptor. The novel energy-conserving role of H2O2 in this catalase-negative bacterium is discussed in relation to its microaerophilic nature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Aerobiosis
  • Bacterial Proteins / metabolism
  • Campylobacter / metabolism*
  • Cytochrome c Group / metabolism
  • Electron Transport
  • Electron Transport Complex IV / metabolism
  • Formates / metabolism
  • Hydrogen Peroxide / metabolism
  • Oxygen / metabolism
  • Peroxidases / metabolism

Substances

  • Bacterial Proteins
  • Cytochrome c Group
  • Formates
  • cytochrome c553
  • formic acid
  • cytochrome C-552
  • Hydrogen Peroxide
  • Peroxidases
  • Electron Transport Complex IV
  • Oxygen