title: Influence of trace elements and nitrogen sources on versicolorin production by a mutant strain of Aspergillus parasiticus.
abstract: A mutant strain of Aspergillus parasiticus blocked in aflatoxin biosynthesis accumulates versicolorin A and versicolorin C. The effect of trace elements on the growth and versicolorin production by this strain was studied in a defined medium. The omission of manganese was slightly stimulatory to versicolorin production; when zinc was omitted from the medium, no detectable versicolorins were produced. Experiments on nitrogen sources in a high-sucrose medium indicated that fourfold to fivefold increases in versicolorin yields could be obtained by substituting 3 ml/l corn steep liquor or 0.1 M NH4NO3 for the 0.023 M (NH4)2SO3 used previously as the nitrogen source in studies on versicolorin production by this strain. These improved yields will facilitate attempts to accumulate enough versicolorin A and versicolorin C for toxicity and carcinogenicity testing. Chromatographic profiles of mycelial extracts of cultures grown in a defined medium with 0.1 M NH4NO3 as the nitrogen source revealed 2 previously unrecognized compounds. The accumulation of these new metabolites in a mutant blocked in aflatoxin production may indicate that they are biosynthetically related to aflatoxin.
mesh_terms: D000880:Anthraquinones / Q000096:biosynthesis*; D001230:Aspergillus / Q000187:drug effects / Q000378:metabolism*; D003470:Culture Media; D008345:Manganese / Q000494:pharmacology; D009154:Mutation; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D014131:Trace Elements / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology
chemical_list: D000880:Anthraquinones; D003470:Culture Media; D000644:Quaternary Ammonium Compounds; D014131:Trace Elements; C005888:versicolorins; D008345:Manganese; D015032:Zinc