Catabolite Effects On Enzyme Induction And Substrate Utilization In Rhizobium leguminosarum

The catabolism of l-histidine and p-hydroxybenzoate in Rhizobium leguminosarum 3841 is inducible. Glucose or succinate have relatively little effect on the induction of histidase whereas they produce about 50% repression of the p-hydroxybenzoate catabolic system. When grown in the presence of a mixture of carbon sources, e.g. glucose plus histidine, or succinate plus p-hydroxybenzoate, the cells co-utilize both substrates. However, consumption of histidine and p-hydroxybenzoate (which support slower growth rates than glucose or succinate) is substantially reduced in comparison with that of glucose or succinate.