The influence of divalent cations and chelators on aflatoxin B1 degradation by Flavobacterium aurantiacum.
The influence of divalent cations (Mg2+ and Ca2+) and chelators (EDTA and 1,10-phenanthroline) on aflatoxin B1 (AFB1) degradation by Flavobacterium aurantiacum was determined in an effort to elucidate the possible manner by which this organism degrades AFB1. AFB1 (10 microg/ml) was added to 72-h cultures of F. aurantiacum that had been washed and resuspended in phosphate buffer (pH 7.0). High-performance liquid chromatography was used to determine AFB1 concentration in these cultures. Incubating cells with 0.1, 1, and 10 mM Ca2+ for 48 h significantly increased AFB1 degradation by 11.8, 13.5, and 14.0%, respectively, compared with F. aurantiacum cells alone. Likewise, incubation with 0.1, 1, and 10 mM Mg2+ for 48 h significantly increased AFB1 degradation by 13.8, 13.3, and 13.1%, respectively. Incubating the bacterium with either divalent cation for 16 and 24 h did not significantly affect AFB1 degradation (P < or = 0.05). Addition of 0.1, 1, and 10 mM EDTA and 0.1 and 1 mM 1,10-phenanthroline resulted in significant increases in AFB1 degradation after 24 h. Significantly less AFB1 degradation was observed using 10 mM 1,10-phenanthroline after 24-h incubation. These results suggest the involvement of Mg2+ and Ca2+ cations in AFB1 degradation by F. aurantiacum.
D'Souza
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Center for Food Safety and Quality Enhancement, Department of Food Science and Technology, The University of Georgia, Griffin 30223-1797, USA.
Brackett
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D016604:Aflatoxin B1 / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D005417:Flavobacterium / Q000187:drug effects / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology; D008274:Magnesium / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
D002413:Cations, Divalent; D010618:Phenanthrolines; D003300:Copper; D004492:Edetic Acid; D016604:Aflatoxin B1; D007501:Iron; D008274:Magnesium; D015032:Zinc; D002118:Calcium; C025205:1,10-phenanthroline