Ultrastructure of a caffeine-resistant mutant of Aspergillus parasiticus during aflatoxin production

Autor: T. O. Dobson, H. G. Stahl, R. L. Buchanan, S. B. Jones
Rok vydání: 1987
Předmět:
Zdroj: Proceedings, annual meeting, Electron Microscopy Society of America. 45:978-979
ISSN: 2690-1315
0424-8201
DOI: 10.1017/s0424820100129176
Popis: Caffeine (1,3,7-trimethylxanthine) inhibits growth and aflatoxin synthesis in A. parasiticus. A caffeine-resistant mutant (BCR1) of A. parasiticus NRRL 2999 was isolated in which sporulation and aflatoxin production occurred only in the presence of caffeine. Further, when cultured in glucose-mineral salts (GMS), BCR1 required amino acids in addition to caffeine in order to produce aflatoxin. A system for ultrastructure study was thus available in which aflatoxin synthesis was controlled by supplementation with amino acids. Experiments were conducted to identify morphology that could be correlated with aflatoxin production in the mutant.Cultures were conidia-initiated in GMS at 28C with agitation, with 6% peptone as amino acid source. Caffeine at 4 mg/ml permitted full growth and stimulated maximal aflatoxin accumulation. Fungal pellets were retrieved at 4 days and portions of the periphery were fixed in 3% glutaraldehyde in 80 mM Na-cacodylate, pH 7.0, for 3 hr.
Databáze: OpenAIRE