A biochemical characterization of histidine auxotrophs of Corynebacterium glutamicum.

Two imidazoleglycerol (IG)-producing mutants and one imidazoleacetol (IA)-producing mutant were selected out of 14 histidine auxotrophs of C. glutamicum, by means of paper-chromatographic analysis of the culture broths of these mutants. Three of the histidine biosynthetic enzymes were determined for these mutants and a previously isolated histidinol-producing mutant of C. glutamicum. The IA-producing mutant and the L-histidinol-pro-ducing mutant had a defect in histidinol phosphate aminotransferase and histidinol dehydro-genase, respectively. IG-producers were not defective in these enzymes. These results were consistent with the histidine biosynthetic sequence known in other microorganisms.