Several tens of mutants were obtained by UV irradiation of a spore suspension of Aspergillus niger. Producers yielding large amounts of citric acid were selected on a modified Czapek agar containing methyl red as pH indicator. After a submerged cultivation in flasks with baffles, a mutant characterized by yellow pigmentation on wort agar and by yields of citric acid up to 74.6% in the medium containing glucose was chosen from 130 isolates tested.

• MeSH
• Aspergillus niger metabolism   MeSH
• Citrates metabolism   MeSH
• Culture Media metabolism   MeSH
• Citric Acid MeSH
• Microbiological Techniques MeSH
• Selection, Genetic MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Citrates MeSH
• Culture Media MeSH
• Citric Acid MeSH
• Carbon MeSH