真菌毒素是由真菌产生的有毒物质,经常,不同的霉菌毒素在食品中共存。曲霉毒素A(OTA)和曲霉毒素B(OTB)可能在多种食物中共存,比如红葡萄酒和小麦,存在显著的人口暴露风险。在这项研究中,我们调查了五种脂肪酶(假丝酵母脂肪酶,南极念珠菌B脂肪酶,蓝藻热霉菌脂肪酶,来自黑曲霉(ANL)和猪胰脂肪酶(PPL)的Amano脂肪酶A)将OTA和OTB水解为非危险产品。只有ANL和PPL降解了两种底物,然而,具有不同程度的效率。PPL完全降解的OTB(9小时),但只有43%的OTA(25小时)。分子模拟表明OTA与PPL的结合能很高,这可以用氯基团的影响来解释,损害水解。ANL能够完全降解两种真菌毒素,OTA在3h和OTB在10h。ANL酶也显示出对OTA的高特异性,然而,这种酶的活性不受氯的影响,并且比OTB更快地水解OTA。这两种酶被发现能够解毒共存的曲霉毒素A和B,使分离的酶成为直接使用微生物缓解食品中霉菌毒素的替代方法。
Mycotoxins are toxic substances produced by fungi and, frequently, different mycotoxins cooccur in food commodities. Ochratoxin A (OTA) and Ochratoxin B (OTB) may co-occur in a variety of foods, like red wines and wheat, presenting a significant risk of population exposure. In this
study, we investigated the potential of five lipases (Candida rugosa Lipase, Candida antarctica B Lipase, Thermomyces lanuginosus Lipase, Amano Lipase A from Aspergillus niger (ANL) and Porcine Pancreas Lipase (PPL)) to hydrolyze OTA and OTB into non-hazardous products. Only ANL and PPL degraded both substrates, however, with varying degrees of efficiency. PPL completely degraded OTB (9 h), but only 43% of OTA (25 h). Molecular simulations indicated a high binding energy of OTA to PPL, that can be explained by the impact of the chlorine group, impairing hydrolysis. ANL was able to completely degrade both mycotoxins, OTA in 3 h and OTB in 10 h. The ANL enzyme showed also high specificity to OTA, however, the activity of this enzyme is not affected by chlorine and hydrolyzes OTA faster than OTB. These two enzymes were found to be able to detoxify co-occurring ochratoxins A and B, making isolated enzymes an alternative to the direct use of microorganisms for mycotoxin mitigation in food.