Manganese Oxidation by Sphaerotilus discophorus

Abstract

Johnson , A. H. (Washington State University, Pullman), and J. L. Stokes . Manganese oxidation by Sphaerotilus discophorus . J. Bacteriol. 91: 1543–1547. 1966.—Cell suspensions of Sphaerotilus discophorus in 0.02 m potassium phosphate buffer ( p H 7.2) readily oxidized MnSO 4 to dark-brown manganic oxide. The latter appeared to be MnO 2 , since its color was the same as MnO 2 and, like the latter, it was readily soluble in HCl with the evolution of chlorine. The amount of O 2 consumed in the oxidation of Mn ++ was 63% or more of theoretical. The ability of the cells to oxidize Mn ++ was destroyed by heating the cells at 93 C for 5 min. Only cell suspensions prepared from cultures of S. discophorus grown with MnSO 4 were able to oxidize Mn ++ . It was concluded that the oxidation of manganous ions by S. discophorus is catalyzed by an inducible enzyme(s).