Academy of National Food and Strategic Reserves Administration, Beijing 100037, China.
School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Toxins (Basel). 2023 May 30;15(6):367. doi: 10.3390/toxins15060367.
Deoxynivalenol (DON) is frequently detected in cereals and cereal-based products and has a negative impact on human and animal health. In this study, an unprecedented DON-degrading bacterial isolate D3_3 was isolated from a sample of larva feces. A 16S rRNA-based phylogenetic analysis and genome-based average nucleotide identity comparison clearly revealed that strain D3_3 belonged to the species . This isolate D3_3 could efficiently degrade 50 mg/L of DON under a broad range of conditions, such as pHs of 7.0-9.0 and temperatures of 18-30 °C, as well as during aerobic or anaerobic cultivation. 3-keto-DON was identified as the sole and finished DON metabolite using mass spectrometry. In vitro toxicity tests revealed that 3-keto-DON had lower cytotoxicity to human gastric epithelial cells and higher phytotoxicity to than its parent mycotoxin DON. Additionally, four genes encoding pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenases in the genome of isolate D3_3 were identified as being responsible for the DON oxidation reaction. Overall, as a highly potent DON-degrading microbe, a member of the genus is reported for the first time in this study. The discovery of this DON-degrading isolate D3_3 and its four dehydrogenases will allow microbial strains and enzyme resources to become available for the future development of DON-detoxifying agents for food and animal feed.
脱氧雪腐镰刀菌烯醇（DON）在谷物及其制品中经常被检测到，对人类和动物的健康有负面影响。在这项研究中，从幼虫粪便样本中分离出了一株前所未有的 DON 降解细菌分离株 D3_3。基于 16S rRNA 的系统发育分析和基于基因组的平均核苷酸同一性比较清楚地表明，菌株 D3_3 属于 。该分离株 D3_3 能够在广泛的条件下（例如 pH 值为 7.0-9.0 和温度为 18-30°C）以及有氧或厌氧培养下，高效降解 50mg/L 的 DON。使用质谱法鉴定出 3-酮-DON 是 DON 的唯一终产物代谢物。体外毒性试验表明，3-酮-DON 对人胃上皮细胞的细胞毒性较低，对 的植物毒性较高。此外，分离株 D3_3 基因组中编码吡咯喹啉醌（PQQ）依赖性醇脱氢酶的四个基因被鉴定为负责 DON 氧化反应。总的来说，作为一种高效的 DON 降解微生物，本研究首次报道了 属的一个成员。发现这种具有高效 DON 降解能力的分离株 D3_3 及其四种脱氢酶，将为未来开发用于食品和动物饲料的 DON 解毒剂提供微生物菌株和酶资源。
