School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
School of Agricultural Engineering, Jiangsu University, Zhenjiang, 212013, China.
Toxicon. 2022 Sep;216:125-131. doi: 10.1016/j.toxicon.2022.07.006. Epub 2022 Jul 15.
Ochratoxin A (OTA), primarily produced by the fungi belonging to the species of Aspergillus and Penicillium, is one of the most common mycotoxins found in cereals and fruits. In addition to resulting in huge economic losses, OTA contamination also poses considerable threat to human and livestock health. Microbial degradation of mycotoxins has been considered with great potential in mycotoxins decontamination. In a previous study, Bacillus velezensis E2 was isolated by our laboratory and showed appreciable inhibitory effect on Aspergillus flavus growth and aflatoxin production in rice grains. In this study, B. velezensis E2 was investigated for its ability to remove OTA and biocontrol against the ochratoxigenic Aspergillus westerdijkiae fc-1. The results revealed that B. velezensis E2 has considerable inhibitory effect on A. westerdijkiae fc-1 both on PDA medium and pear fruits, with inhibitory rate of 51.7% and 73.9%, respectively. In addition, its ability to remove OTA was evaluated in liquid medium and the results showed that more than 96.1% of OTA with an initial concentration of 2.5 μg/mL could be removed by B. velezensis E2 in 48 h. Further experiments revealed that enzymatic transformation and alkaline hydrolysis might be the main mechanisms related to OTA degradation by B. velezensis E2, with ring open ochratoxin α (OP-OTα) as a possible degradation product. Our study indicated that the B. velezensis E2 strain could be a potential bacterial candidate in biodegradation of OTA and biocontrol against A. westerdijkiae fc-1.
赭曲霉毒素 A（OTA）主要由曲霉属和青霉属真菌产生，是谷物和水果中最常见的霉菌毒素之一。OTA 污染不仅会导致巨大的经济损失，还会对人类和牲畜的健康构成相当大的威胁。霉菌毒素的微生物降解在霉菌毒素脱毒方面具有很大的潜力。在之前的研究中，我们实验室分离到一株解淀粉芽孢杆菌 E2，该菌对大米中的黄曲霉生长和黄曲霉毒素的产生有明显的抑制作用。在本研究中，研究了解淀粉芽孢杆菌 E2 去除 OTA 的能力及其对产赭曲霉毒素的西地西霉菌 fc-1 的生防作用。结果表明，解淀粉芽孢杆菌 E2 对 PDA 培养基和梨果实中的西地西霉菌 fc-1 均有较强的抑制作用，抑制率分别为 51.7%和 73.9%。此外，还在液体培养基中评估了其去除 OTA 的能力，结果表明，初始浓度为 2.5μg/mL 的 OTA 可在 48 h 内被解淀粉芽孢杆菌 E2 去除 96.1%以上。进一步的实验表明，酶转化和碱性水解可能是解淀粉芽孢杆菌 E2 降解 OTA 的主要机制，环开裂赭曲霉毒素 α（OP-OTα）可能是其降解产物之一。本研究表明，解淀粉芽孢杆菌 E2 菌株可能是 OTA 生物降解和生防西地西霉菌 fc-1 的潜在细菌候选菌株。
