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

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 Cunninghamellaelegans 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, Cunninghamellaelegans preferably produced Z14S, while Cunninghamellaechinulata preferably produced Z14G. In the sulphate-depleted medium a dramatic change was observed for Cunninghamellaelegans, 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.

Developments in mycotoxin analysis: an update for 2020-2021

“…It is also worth mentioning biotransformation by plants or microorganisms as another option of gaining these rare and rather expensive mycotoxin conjugates. Recently, Peters et al (2021) introduced an easily implementable microbiological method for production of ZEN glycosides. This was achieved by Cunninghamella fungal strains in sulphate-depleted media, where the lack of sulphur steered the reaction towards the preferred abundant production of .…”

“…https://www.wageningenacademic.com/doi/pdf/10.3920/WMJ2021. 2752-Sunday, March 06, 2022 Interestingly, when the developed approach was applied for other mycotoxins (namely DON, AFB 1 , FB 1 , T-2, and OTA, no obvious biotransformation was observed at the conditions previously used for ZEN (Peters et al, 2021) indicating that different microorganisms have specific metabolic pathways for detoxification of different mycotoxins. For checking the concentrations of standards of conjugated mycotoxins, measurement of absorbance and calculation of concentrations via the molar absorption coefficients, as described by Scheibenzuber et al (2021) is highly recommended.…”

Pore Size Adjustment Strategy for the Fabrication of Molecularly Imprinted Covalent Organic Framework Nanospheres at Room Temperature for Selective Extraction of Zearalenone in Cereal Samples

“…ZEN is hard to degrade or remove during food processing due to its high thermal stability . According to the European Food Safety Authority, the tolerable daily intake for ZEN should not exceed 0.25 μg kg –1 of body weight . The maximum tolerable content (20–400 μg kg –1 ) of ZEN in food products for human is specified by the European Commission, while the limit of ZEN in wheat and maize is 60 μg kg –1 in Chinese food safety standards (GB 2761-2017) .…”

“…3 According to the European Food Safety Authority, the tolerable daily intake for ZEN should not exceed 0.25 μg kg −1 of body weight. 4 The maximum tolerable content (20−400 μg kg −1 ) of ZEN in food products for human is specified by the European Commission, 5 while the limit of ZEN in wheat and maize is 60 μg kg −1 in Chinese food safety standards (GB 2761-2017). 6 Therefore, development of analytical methods for selective and precise determination of trace ZEN in complex food samples is of great significance in food safety.…”