EFFECT OF MIXTURES OF SUBSTRATES ON THE BIOSYNTHESIS OF INDUCIBLE ENZYMES IN AEROBACTER AEROGENES

Abstract

Synthesis of 3 inducible enzymes was studied during growth of A. aerogenes in media containing a second source of C and energy in addition to the particular substrate-inducer. While glucose causes a complete cessation of induced enzyme formation, several other compounds produce partial inhibitions related to the growth-supporting property of the second compound. The faster the growth of the cells on this substance, the greater is the inhibition exerted on formation of the enzymes directed at the first substance. The presence of myo-inositol in an L-histidine medium causes 40% reduction in the synthesis of histidase. Scyllitol, an inhibitor of myo-inositol dissimilation, does not reverse inhibition of histidase formation. It is concluded that the cause of the restricted histidase biosynthesis is the actual production of myo-inositol-degrading enzymes, but this explanation is not valid for the glucose-caused inhibitions of induced enzyme formation.