title: Adsorption and degradation of zearalenone by bacillus strains.
abstract: Two Bacillus strains; Bacillus subtilis 168 and Bacillus natto CICC 24640 separately adsorbed and degraded zearalenone in liquid media, in vitro. Viable, autoclaved (121°C, 20 min) and acid-treated cells of both strains separately bound more than 55% of zearalenone (ZEN, 20 μg/L) after 30 min and 1-h incubation at 37°C under aerobic conditions, and the amount of ZEN adsorbed was dependent on initial cell volume. In addition, ZEN was degraded by the culture extract of both strains. Degradation by B. subtilis 168 and B. natto CICC 24640 culture extract after 24-h aerobic incubation at 30°C was 81% and 100%, respectively. B. natto CICC 24640 culture extract comprehensively degraded ZEN and, for both strains, no oestrogenic ZEN analogues were present. ZEN degradation was accompanied by carbondioxide emission indicating a decarboxylation reaction. ZEN degradation by the salient B. natto CICC 24640 culture extract varied with initial ZEN concentration, incubation time, temperature and pH. Degradation was enhanced by Mn(2+), Zn(2+), Ca(2+) and Mg(2+) but impeded by Hg(2+), Cu(2+), Pb(2+), ethylenediaminetetraacetic acid and 1,10-phenanthroline. The degradation reaction is associated with a metalloproteinase of molar mass in the range 31-43 kDa. Overall, the two generally recognised as safe Bacillus strains can, potentially, be utilised for detoxification of zearalenone in food.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Samuel Edgar
authors.initials: SE
authors.lastname: Tinyiro
authors.forename: Cuthbert
authors.initials: C
authors.lastname: Wokadala
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.forename: Weirong
authors.initials: W
authors.lastname: Yao
mesh_terms: D000327:Adsorption; D001407:Bacillus / Q000378:metabolism*; D001711:Biotransformation; D002413:Cations, Divalent / Q000378:metabolism; D002614:Chelating Agents / Q000378:metabolism; D013696:Temperature; D015025:Zearalenone / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D002614:Chelating Agents; D015025:Zearalenone