The genetic analysis of regulation of amidase synthesis in Aspergillus nidulans. I. Mutants able to utilize acrylamide

Summary Aspergillus nidulans uses an acetamidase enzyme to grow on acetamide as a carbon or as a nitrogen source. Acrylamide is a substrate for the enzyme but does not induce its synthesis. Mutants capable of growing on acrylamide as a nitrogen source have been isolated. Two classes of mutant have been found —amdR ^c mutants on linkage group II andamdT ^c on linkage group III.amdR ^c mutants produce high constitutive acetamidase levels. The enzyme is still inducible by amides, but to a lesser extent than wild type, and is still subject to repression by ammonia and by carbon metabolites derived from glucose.amdR ^c mutants are semi-dominant to the wild type allele in heterozygous, diploids. TheamdT ^c mutant is not subject to carbon metabolite repression, of the acetamidase. The enzyme is inducible by amides and repressible by ammonia. TheamdT ^c mutation also results in reduced ability to grow on formamide as a nitrogen source and to lowered levels of a second amidase enzyme.amdT ^c is semi-dominant in heterozygous diploids.