A new selection method for isolating mutants defective in acetate utilisation in Aspergillus nidulans.

Propionate medium is normally toxic for the growth of Aspergillus nidulans. Spontaneous mutations relieving the toxicity to propionate, which arose on propionate medium, have been shown to be mutations in acetate metabolism. One acu- mutant is allelic with acuA (the structural gene for acetyl-CoA synthetase), another with acuB (the regulatory gene involved in the induction of enzymes concerned with acetate metabolism, including acetyl-CoA synthetase), and a third mutant, acuO, represents a new acu- locus that maps on linkage group V.