A Novel Microbial Zearalenone Transformation through Phosphorylation.

Yan Zhu,Honghui Zhu,Dion Lepp,Xiu-Zhen Li,Pascal Drouin,Ting Zhou,Mathieu Castex

doi:10.3390/toxins13050294

Yan Zhu, Honghui Zhu + Show 5 more

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https://doi.org/10.3390/toxins13050294

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Journal: Toxins	Publication Date: Apr 21, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: Agriculture and Agri-Food Canada, Lallemand (Canada)

Abstract

Zearalenone (ZEA) is a mycotoxin widely occurring in many agricultural commodities. In this study, a purified bacterial isolate, Bacillus sp. S62-W, obtained from one of 104 corn silage samples from various silos located in the United States, exhibited activity to transform the mycotoxin ZEA. A novel microbial transformation product, ZEA-14-phosphate, was detected, purified, and identified by HPLC, LC-MS, and NMR analyses. The isolate has been identified as belonging to the genus Bacillus according to phylogenetic analysis of the 16S rRNA gene and whole genome alignments. The isolate showed high efficacy in transforming ZEA to ZEA-14-phosphate (100% transformation within 24 h) and possessed advantages of acid tolerance (work at pH = 4.0), working under a broad range of temperatures (22–42 °C), and a capability of transforming ZEA at high concentrations (up to 200 µg/mL). In addition, 23 Bacillus strains of various species were tested for their ZEA phosphorylation activity. Thirteen of the Bacillus strains showed phosphorylation functionality at an efficacy of between 20.3% and 99.4% after 24 h incubation, suggesting the metabolism pathway is widely conserved in Bacillus spp. This study established a new transformation system for potential application of controlling ZEA although the metabolism and toxicity of ZEA-14-phosphate requires further investigation.

Highlights

Zearalenone (ZEA), chemically characterized as a macrocyclic β-resorcyclic acid lactone, is an estrogenic mycotoxin produced by Fusarium spp
Moldy hay and grain used as concentrates in animal feeds may contain the toxin carried over from contaminated crops [3,4]
According to the European Food Safety Authority (EFSA) [5], ZEA was detected in 15% of 9877 unprocessed grains and 13,075 of food samples collected in 19 European countries between 2005 and 2010

Summary

Introduction

Zearalenone (ZEA), chemically characterized as a macrocyclic β-resorcyclic acid lactone, is an estrogenic mycotoxin produced by Fusarium spp. [1]. Moldy hay and grain used as concentrates in animal feeds may contain the toxin carried over from contaminated crops [3,4]. According to the European Food Safety Authority (EFSA) [5], ZEA was detected in 15% of 9877 unprocessed grains and 13,075 of food samples collected in 19 European countries between 2005 and 2010. In that survey the average ZEA level detected in unprocessed corn was 87 μg/kg with the maximal concentration as high as 2700 μg/kg. ZEA-producing fungi are inhibited by low pH and anaerobic conditions, contamination by ZEA is not mitigated during the process [6]. These conditions (i.e., acidic and anaerobic environment) bring challenges for ZEA detoxification by microorganisms

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