Involvement of the Cyanide-Insensitive Respiration in Bacterivorous Growth in the Myxamoebae of a True Slime Mold, Didymium sp. Strain H-1

Abstract

The aerophilic growth of the myxamoebae of a true slime mold, Didymium sp. strain H-1, was studied. Two pathways of oxygen uptake, the cyanide-sensitive and cyanide-insensitive pathways, existed in the myxamoebae. Superoxide anions were produced by the cyanide-insensitive respiration. The cyanide-insensitive respiration had a low affinity for oxygen and the growth yield vs. oxygen concentration was the same pattern as the respiratory activity. The growth of myxamoebae is concluded to be controlled by the activity of the cyanide-insensitive respiration. The importance of the cyanide-insensitive respiration of the myxamoebae in a microenvironment was discussed.