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.

Biodegradation and biodetoxification of Fusarium mycotoxins by Sphaerodes mycoparasitica

“…However, metabolic products of ZEN were not identified from those strains. A possible pathway might comprise of cleavage of a ring structure followed by decarboxylation for complete degradation of ZEN as shown by Bacillus strains (Tinyiro et al 2011). Besides bacteria, several fungi were known as degrader of ZEN by producing different metabolites of ZEN: Rhizopus spp.…”

Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins

“…A number of studies have evaluated intrinsic factors, including carbon source [26,34], nitrogen source [26,34,88], vitamins [26], metals ions [12,34,46,89,90,91,92,93], enzyme inhibitors and promoters [52,89,90,91,92,93,94], initial concentration of mycotoxins [93,95], initial concentration of cells [53,95] and initial pH value [12,14,17,26,31,34,41,46,54,60,88,89,95,96], as well as extrinsic factors, including temperature [12,14,17,25,26,31,34,38,41,46,52,54,60,88,89,95,96], aeriation (shaking rate) [26], oxygen preference [14], as well as pre-incubation [26] and incubation time [34,97]. The experimental designs and optimized biotransformation conditions are summarized in Table 2.…”

Detoxification of zearalenone by three strains of lactobacillus plantarum from fermented food in vitro

“…Extracellular extracts of Bacillusnatto CICC 24640 and Acinetobacter sp. SM04 degraded ZEA in a continuous process, and more than 50% of ZEA was degraded in 12 h (Tinyiro et al, 2011;Yu et al 2011). However, Lactobacillus rhamnosus GG or L. rhamnosus LC705 decreased the amount of ZEA by physically binding the molecule in a rapid reaction because approximately 60% of ZEA was removed from the liquid media within 10 min, and no significant difference was observed up to 72 h (El-Nezami et al 2002).…”