ABSTRACT
Cytochromes, hemoglobin, myoglobin, catalase, peroxidase, and several other proteins contain iron-heme prosthetic groups. Formation of these proteins requires a supply of both the apoprotein and the prosthetic group. A wide range of bacteria form cytochromes, catalase, peroxidase, and various oxygenases. Most of these organisms are able to biosynthesize both the apoprotein and the heme prosthetic groups. Many strictly anaerobic bacteria and facultatively anaerobic bacteria growing anaerobically are able to synthesize cytochromes. Extracts derived from Escherichia coli grown anaerobically in nitrate- or fumarate-containing media can form protoporphyrin from protoporphyrinogen in the presence of these electron acceptors. The apoenzymes of the cytochromes and catalase were present in anaerobically grown bacteria, as addition of hemin or aeration of washed suspensions caused a rapid increase in catalase and respiratory activity. The formation of catalase when grown in the presence of hematin indicates the ability of some lactic acid bacteria to form hemoproteins.
