Genetic characterization of mutations affecting conidiophore length in Aspergillus niger strain N402

Aspergillus niger is a filamentous fungus important in industrial biotechnology for the production of citric acid and enzymes. To facilitate handling of A. niger spores and to prevent cross-contamination between different strains, the N400 wild-type strain was UV-mutagenized in two consecutive rounds to sequentially generate strains N401 and N402. N402 exhibits reduced conidiophore length and radial growth. N402 and its derivatives have been, and still are, used for most molecular genetic studies in A. niger. To identify the mutations (dubbed cspA and cspB) responsible for the phenotypes of N401 and N402, the genomes were sequenced and compared to the N400 genome sequence.