Dimethyl sulphoxide respiration in Proteus mirabilis.

Dimethyl sulphoxide (DMSO) was found to serve as an electron acceptor for the anaerobic growth of Proteus mirabilis on fermentable substrates such as glucose and pyruvate, as well as on oxidizable substrates such as glycerol and lactate. In a complex medium, formate greatly stimulated growth in the presence of DMSO. Cell extracts were found to reduce DMSO to dimethyl sulphide (DMS) in the presence of an electron donor. It was found that NADH, formate, lactate, reduced benzyl viologen, and dithionite can serve as electron donors. Chlorate resistant (chl) mutants were found to be unable to grow using DMSO as an electron acceptor. However, in one chl mutant, growth and DMSO reduction could be partially restored by growth in the presence of high concentrations of molybdate.