title: Uptake of aflatoxin B1 and T-2 toxin by two mycotoxin bioassay microorganisms: Kluyveromyces marxianus and Bacillus megaterium.
abstract: Uptake of aflatoxin B1 (AFB1) and trichothecene T-2 toxin from growth medium by mycotoxin bioassay strains of Klutyveomyces marxianus and Bacillus megaterium was assessed by incubating, washing, and sonicating the cells, extracting samples with chloroform, and analysing the extracts by a combination of high-performance thin-layer chromatography (HPTLC) and fluorescence densitometry. Using cultures of K. marxianus, the entire AFB1 dose was recovered and no AFB1 metabolites were detected. Less than 1% of the AFB1 was recovered from the cells, and AFB1 did not inhibit growth. Methanol in the incubation medium had no significant effect on the levels of AFB1 associated with K. marxianus cells. The entire dose of T-2 toxin was also recovered from K. marxianus cultures, and no metabolites were detected; again, less than 1% of T-2 toxin was cell-associated, but growth was completely inhibited. AFB1 partially inhibited the growth of B. megaterium; approximately 12% of the dose could not be recovered, and no AFB1-related metabolites were detected. Methanol increased the levels of recoverable AFB1 associated with B. megaterium cells. In the case of T-2 toxin, around 8% of the dose was not recovered, and no metabolites were detected; growth of B. megaterium was stimulated. These results suggest irreversible binding of both toxins, or derivatives of them, to the cells of B. megaterium.
authors.affiliation: School of Chemical and Life Sciences, University of Greenwich, Woolwich, London, UK.
authors.forename: K H
authors.initials: KH
authors.lastname: Engler
authors.forename: R D
authors.initials: RD
authors.lastname: Coker
authors.forename: I H
authors.initials: IH
authors.lastname: Evans
mesh_terms: D016604:Aflatoxin B1 / Q000378:metabolism* / Q000494:pharmacology; D001410:Bacillus megaterium / Q000254:growth & development / Q000378:metabolism*; D001681:Biological Assay; D001692:Biological Transport; D007716:Kluyveromyces / Q000235:genetics / Q000378:metabolism*; D000432:Methanol / Q000494:pharmacology; D013605:T-2 Toxin / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D016604:Aflatoxin B1; D013605:T-2 Toxin; D000432:Methanol