Abstract
The catalase level of Bacteroides distasonis (ATCC 8503, type strain) varied with the amount of hemin supplied to the medium when the cells were grown in either a prereduced medium containing 0.5% peptone, 0.5% yeast extract, and 1% glucose or in a prereduced, defined heme-deficient medium. The effect of hemin on catalase production could not be duplicated by ferrous sulfate or ferrous ammonium citrate. Catalase activity reached peak values in late log phase, whereas superoxide dismutase specific activity remained constant throughout the culture growth cycle. The catalase was a nondialyzable, cyanide and azide-sensitive, heat-labile protein that coeluted with bovine erythrocyte catalase from Sepharose 6 B. Analysis of polyacrylamide gels stained for catalase activity and for heme showed a correspondence between the single catalytic activity band and one of three heme-protein bands. These data suggest a heme-protein of approximately 250,000 molecular weight. The superoxide dismutase was a cyanide-insensitive protein of approximately 40,000 molecular weight that migrated electrophoretically on acrylamide gels as a single band of activity.