Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Int J Food Microbiol. 2019 Feb 16;291:10-16. doi: 10.1016/j.ijfoodmicro.2018.11.001. Epub 2018 Nov 5.
Ochratoxin A (OTA) is a nephrotoxic mycotoxin which may contaminate various foods and feed products worldwide. Aspergillus niger is one of the species responsible for OTA contamination in grapes and derived products. This species has recently been split into A. niger and Aspergillus welwitschiae. Both species can not be distinguished by phenotypic or extrolite profiles and to date there is no ecophysiological information of A. welwitschiae. The aim of this study was to determine the effects of water activity (a) (0.90; 0.95 and 0.98-0.99), culture media (Yeast Extract Sucrose Broth (YESB); Synthetic Grape Juice Medium (SGM); White grape juice (WGJ)) and temperature (15 °C, 25 °C and 35 °C) on the growth and OTA production of four strains of A. niger and six strains of A. welwitschiae. The assay was performed in microtiter plates, determining the absorbance at 530 nm and the concentration of OTA at 1, 2, 4 and 10 days. No significant differences were observed in absorbance and OTA values between the two species under study. The highest absorbance values were recorded in YESB, followed by SGM and WGJ. Absorbance values increased with increasing a and temperature. The highest OTA values were obtained at 0.98-0.99 a and the best culture media for OTA production was YESB, followed by WGJ and SGM. The studied strains of A. niger produced the highest mean OTA level at 25 °C whereas A. welwitschiae strains produced the highest mean OTA concentration at 15 °C, although not differing significantly from concentration produced at 25 °C. To our knowledge, this is the first report on the impact of some environmental factors on growth and OTA production by A. welwitschiae.
赭曲霉毒素 A（OTA）是一种肾毒性真菌毒素，可能会污染世界各地的各种食品和饲料产品。黑曲霉是导致葡萄及衍生产品中 OTA 污染的物种之一。该物种最近已被分为黑曲霉和宛氏拟青霉。这两个物种不能通过表型或外生代谢物特征来区分，迄今为止，尚无宛氏拟青霉的生态生理学信息。本研究的目的是确定水分活度（a）（0.90；0.95 和 0.98-0.99）、培养基（酵母提取物蔗糖肉汤（YESB）；合成葡萄汁培养基（SGM）；白葡萄汁（WGJ））和温度（15°C、25°C 和 35°C）对 4 株黑曲霉和 6 株宛氏拟青霉菌株生长和 OTA 产生的影响。该测定在微量滴定板中进行，在 1、2、4 和 10 天测定 530nm 处的吸光度和 OTA 浓度。在所研究的两个物种中，未观察到吸光度和 OTA 值之间存在显著差异。在 YESB 中记录到的吸光度值最高，其次是 SGM 和 WGJ。吸光度值随 a 和温度的升高而增加。在 0.98-0.99 a 时获得最高的 OTA 值，用于 OTA 产生的最佳培养基是 YESB，其次是 WGJ 和 SGM。研究的黑曲霉菌株在 25°C 时产生的平均 OTA 水平最高，而宛氏拟青霉菌株在 15°C 时产生的平均 OTA 浓度最高，尽管与 25°C 时的浓度没有显著差异。据我们所知，这是首次报道一些环境因素对宛氏拟青霉生长和 OTA 产生的影响。
