Nitrogen Catabolite Repression in Yeasts and Filamentous Fungi

Publisher Summary This chapter provides a brief description of nitrogen catabolite repression in Saccharomyces cerevisiae. The ancestral use of yeasts in industry has led to the selection of many wild-type strains of Saccharomyces cerevisiae. Saccharomyces spp. are very different from bacteria, although in vegetative growth they can be handled in a similar way. This is probably the origin of the choice of these organisms when prokaryotic cellular physiologists became interested in eukaryotic organisms. Anabolism, catabolism, and regulation of arginine metabolism have also been studied in parallel in Saccharomyces cerevisiae. The chapter also discusses the nitrogen metabolite repression in filamentous fungi. A number of filamentous fungi are able to utilize a wide range of nitrogen sources. This metabolic versatility implies a strong selective pressure for a mechanism to ensure preferential utilization of the favorable nitrogen sources. This mechanism, nitrogen metabolite repression of the syntheses of many enzymes and permeases involved in nitrogen nutrition, has been extensively studied in two filamentous fungi, the ascomycetes Aspergillus nidulans and Neurospora crassa.