Ammonium assimilation in Nocardia asteroides

Specific enzymes of ammonium assimilation were measured in cell-free extracts of Nocardia asteroides grown in a synthetic medium with glutamate as the nitrogen source. Cell-free extracts had active glutamine synthetase (GS) and glutamate synthase (GOGAT) and alanine dehydrogenase (ADH) but glutamate dehydrogenase (GDH) could not be detected in the enzyme preparation. This shows that GS/GOGAT is the major pathway of ammonium assimilation in N. asteroides.