Identification and degradation characteristics of a zearalenone degrading bacterium

Abstract:

[Background] Zealenone (ZEN) is a mycotoxin with estrogen-like effect, which often contaminates grains and feed, and threatens the health of animals and humans seriously. As an ideal method to remove ZEN, the biological detoxification has been received with wide attentions. However, there are few related degradation strains, which need to be further screened. [Objective] To clarify the biological classification status of a ZEN-degrading bacterium and optimize the degradation conditions. [Methods] The phylogenetic tree was constructed by 16S rRNA gene sequences. Optimization of culture conditions with single factor analysis was carried out, and degradation kinetic of ZEN was analyzed. [Results] Based on 16S rRNA gene sequence similarities, the closest relative of WLB-29 was Stappia indica B106T (97.47%), which suggested WLB-29 was a potential novel species of the genus Stappia (GenBank accession number MT196321). Results of the optimization showed that the best conditions for strains to degrade ZEN were followed: LB culture medium, 37 °C, pH 8.0, 2% inoculum and initial concentration of 10 mg/L ZEN. Under the conditions, the degradation rate could reach 92.56% after cultured 144 hours. [Conclusion] The strain WLB-29 could degrade ZEN. It provides a research basis for further analyzing the mechanism of ZEN degradation by the strain, and utilization of the strain to ZEN detoxification in future.