Abstract
Aflatoxin G1 (AFG1) was transformed into aflatoxin B3 (AFB3) by the fungiRhodotorula sp,Sporobolomyces sp,Rhizopus oryzae NRRL395,Pythium ultimum, Aspergillus terreus, A clavatus and Penicillium frequentans grown in a medium containing AFG1, Difco potato dextrose broth, yeast extract, and peptone both in liquid shaken cultures and in solid static cultures at 25°C in the dark. A maximum rate of transformation of 10 % was obtained after 2 to 3 weeks of incubation. The transformation was correlated with an increase in the pH of the media from 5.7 –5.9 to 8.3 – 8.8.Saccharomyces cerevisiae also transformed AFG1 into AFB3, but at a slower rate; the pH of the media did not reach above 8.0 until 5 weeks after incubation. No transformation was observed whenA niger andP chrysogenum were tested; in both cases, no increase in pH was noticed. However, some transformation of AFG1 to AFB3 by both fungi was observed when the initial pH of the media was adjusted to 9.0. The rate of transformation increased to 15 – 20% in the static culture where the same medium was adsorbed onto vermiculite andRhizopus andAspergilli gave the highest increase in AFB3 yield.
Similar content being viewed by others
References
Heathcote JG and Dutton MF (1969) New metabolites ofAspergillus flavus. Tetrahedron 25:1497–1500
Stubblefield RD, Shotwell OL, Shannon GM, Weisleder D, and Rohwedder WK (1970) Parasiticol: A new metabolite fromAspergillus parasiticus. J Agri Food Chem 18:391–393
Cole RJ and Kirksey JW (1971) Aflatoxin G1 metabolism byRhizopus species. J Agri Food Chem 19:222–223
Batnicki-Garcia S (1968) Cell wall chemistry, morphogenesis and taxonomy of fungi. Ann Rev Microbiol 22: 87–108
Chu FS (1971) Chromatography of crude aflatoxins on adsorbosil — 5. J Assoc Off Anal Chem 54:1304–1306
Chu FS and Butz ME (1970) Spectrophotofluorodensitometric measurement of ochratoxin A in cereal products. J Assoc Off Anal Chem 53:1253–1257
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lisker, N., Zhang, G. & Chu, F.S. Bioconversion of Aflatoxin G1 to Aflatoxin B3 by selected fungi. Mycotox Res 6, 67–72 (1990). https://doi.org/10.1007/BF03192145
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF03192145