Brodehl Antje, Möller Anne, Kunte Hans-Jörg, Koch Matthias, Maul Ronald
Department of Analytical Chemistry, Reference Materials, BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Materials and Environment, BAM Federal Institute for Materials Research and Testing, Berlin, Germany.
FEMS Microbiol Lett. 2014 Oct;359(1):124-30. doi: 10.1111/1574-6968.12586. Epub 2014 Sep 11.
Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin biosynthesized by various Fusarium fungi. These fungal species frequently infest grains; therefore, ZEN represents a common contaminant in cereal products. The biotransformation of ZEN differs significantly from species to species, and several metabolites are known to be formed by animals, plants, and microorganisms. The aim of the present study was to investigate the microbial conversion of ZEN by species of the genera Rhizopus and Aspergillus representing relevant fungi for food processing (e.g. fermentation). To monitor the ZEN metabolism, ZEN was added to liquid cultures of the different fungal species. After a period of 3 days, the media were analyzed by HPLC-MS/MS for metabolite formation. Two Aspergillus oryzae strains and all seven Rhizopus species were able to convert ZEN into various metabolites, including ZEN-14-sulfate as well as ZEN-O-14- and ZEN-O-16-glucoside. Microbial transformation of ZEN into the significantly more estrogenic α-zearalenol (α-ZEL) was also observed. Additionally, a novel fungal metabolite, α-ZEL-sulfate, was detected. Semi-quantification of the main metabolites indicates that more than 50% of initial ZEN may be modified. The results show that fungal strains have the potential to convert ZEN into various metabolites leading to a masking of the toxin, for example in fermented food.
玉米赤霉烯酮（ZEN）是一种由多种镰刀菌生物合成的非甾体雌激素类霉菌毒素。这些真菌物种经常侵染谷物；因此，ZEN是谷物产品中常见的污染物。ZEN的生物转化在不同物种之间存在显著差异，已知动物、植物和微生物会形成几种代谢产物。本研究的目的是调查根霉属和曲霉属物种对ZEN的微生物转化，这些属代表了食品加工（如发酵）中的相关真菌。为了监测ZEN的代谢情况，将ZEN添加到不同真菌物种的液体培养物中。3天后，通过高效液相色谱-串联质谱法（HPLC-MS/MS）分析培养基中代谢产物的形成情况。两株米曲霉菌株和所有七种根霉物种都能够将ZEN转化为多种代谢产物，包括ZEN - 14 - 硫酸盐以及ZEN - O - 14 - 和ZEN - O - 16 - 葡萄糖苷。还观察到ZEN被微生物转化为雌激素活性显著更高的α-玉米赤霉烯醇（α-ZEL）。此外，还检测到一种新型真菌代谢产物α-ZEL - 硫酸盐。主要代谢产物的半定量分析表明，初始ZEN中超过50%可能被修饰。结果表明，真菌菌株有可能将ZEN转化为多种代谢产物，从而导致毒素被掩盖，例如在发酵食品中。
