The fungus Stropharia semiglobata uses glutamate dehydrogenase and glutamine synthetase/glutamate synthase to absorb ammonia for growth. The fungus represses both forms of glutamate dehydrogenase when ammonia levels rise, but NADP-GDH is more active than NAD-GDH. Glutamine synthetase and glutamate synthase are also active in the fungus and work independently of ammonia levels. Through enzyme activity and labeling studies, it is clear that both glutamate dehydrogenase and glutamine synthetase/glutamate synthase play a role in absorbing ammonia in this fungus.