AN ADAPTIVE PEROXIDATION BY STREPTOCOCCUS FAECALIS

Abstract

Cultures of S. faecalis B33A, grown with free access to air, produce about 30% more cells for an equal expenditure of glucose than do deep-grown cultures. The shallow-grown cells oxidize glucose and glycerol at a constant rate and without the accumulation of peroxide. Deep-grown cells in these circumstances accumulate peroxide to such an extent that the oxidation ceases. Shallow-grown cells rapidly utilize peroxide, added in small amts., in the presence of oxidizable substrates. With free access to O2 about 1.3 [mu][image]. of glucose are dissimilated per [mu][image] of O2 consumed by the shallow-grown cells, whereas deep-grown cells use about 0.8 [mu][image] of glucose per [mu][image] of O2 consumed. The mechanism in the shallow-grown cells that is concerned in these reactions, appears to be a peroxidase-like reaction that supplements other oxidizing mechanisms of the cell.