Effect of Medium on H(2)O(2) Levels and Peroxidase-Like Activity by Mycoplasma pneumoniae.

H(2)O(2) levels accumulated by Mycoplasma pneumoniae can be influenced by carbon source, different horse sera, yeast extract, thallium acetate, or growth in a simplified, dialyzed medium. Thus, increased levels of H(2)O(2) were detected by growth in glycerol, by omission of thallium acetate, and by the use of dialyzed medium. The ability of M. pneumoniae in the presence of glucose, but not with fructose, mannose, or glycerol, to remove both endogenous and exogenous H(2)O(2) suggests an inducible peroxidase similar to bacterial enzymes in streptococci. This peroxidase-like activity is in turn influenced by the complex interplay of medium components, explaining perhaps some of the variability of H(2)O(2) accumulations observed with glucose. A survival value has been suggested for this "peroxidase-like" activity.