Controlled Production of Zearalenone-Glucopyranoside Standards with Cunninghamella Strains Using Sulphate-Depleted Media.

Jeroen Peters,Arjen Gerssen,Maurice C R Franssen,Michel W F Nielen,Edward Ash,Ruud Van Dam

doi:10.3390/toxins13060366

Jeroen Peters, Arjen Gerssen + Show 4 more

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https://doi.org/10.3390/toxins13060366

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Abstract

In recent years, conjugated mycotoxins have gained increasing interest in food safety, as their hydrolysis in human and animal intestines leads to an increase in toxicity. For the production of zearalenone (ZEN) glycosides reference standards, we applied Cunninghamella elegans and Cunninghamella echinulata fungal strains. A sulphate-depleted medium was designed for the preferred production of ZEN glycosides. Both Cunninghamella strains were able to produce zearalenone-14-β-D-glucopyranoside (Z14G), zearalenone-16-β-D-glucopyranoside (Z16G) and zearalenone-14-sulphate (Z14S). In a rich medium, Cunninghamella elegans preferably produced Z14S, while Cunninghamella echinulata preferably produced Z14G. In the sulphate-depleted medium a dramatic change was observed for Cunninghamella elegans, showing preferred production of Z14G and Z16G. From 2 mg of ZEN in sulphate-depleted medium, 1.94 mg of Z14G and 0.45 mg of Z16G were produced. Following preparative Liquid Chromatography-Mass Spectrometry (LC-MS) purification, both fractions were submitted to 1H and 13C NMR and High-Resolution Mass Spectrometry (HRMS). These analyses confirmed that the purified fractions were indeed Z14G and Z16G. In conclusion, the presented research shows that a single Cunninghamella strain can be an effective and efficient tool for the controlled biotransformation of ZEN glycosides and other ZEN metabolites. Additionally, the biotransformation method was extended to zearalanone, β-zearalenol and other mycotoxins.

Highlights

To further optimize future production, the implementation of larger culture volumes in dedicated bioprocessors, tweaking temperatures and especially aeration [42], while fortifying at lower ZEN concentrations may lead to more optimal production of ZEN glycosides
Besides the effective glycoside production, it is at the same time an effective tool to produce the Z14S metabolite when using the standard
The High-Resolution Mass Spectrometry (HRMS) run of a sub-optimal biotransformation (Figure 1A) revealed several phase I and phase II ZEN metabolites, including ZEN-hydroxy compounds

Summary

Introduction

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by Fusarium spp. It occurs in grain commodities, and it can cause reproductive disorders in farm animals and lead to hypoestrogenic syndromes in humans [1]. 10 samples contained Z14G with concentrations ranging from 17 to 104 μg/kg. In their survey of cereal-based foods, De Boevre et al [10] found the conjugated mycotoxins Z14G, Z14S, α-ZELG and β-ZELG with maximum concentrations of, respectively, 369, 45, 192 and 206 μg/kg. Nathanail et al [12] analyzed different commodities of Finnish cereal grains and detected Z14G, Z16G, α-ZELG, β-ZELG and Z14S in oats, with the highest concentrations being, respectively, 9.6, 15.1, 5.1, 0.7 and 220 μg/kg. Borzekowkski et al [14] showed that some tempeh products, acquired from Indonesian markets, contained ZEN, α-ZEL and Z14S

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