Bejaoui H, Mathieu F, Taillandier P, Lebrihi A
ENSAT/INPT: 1, Av. de l'Agrobiopôle BP32607, Auzeville-Tolosane, Castanet-Tolosan, 31326, France.
J Agric Food Chem. 2005 Oct 19;53(21):8224-9. doi: 10.1021/jf051029v.
Biological removal of ochratoxin A (OTA) by living and heat-treated dead conidia of black Aspergillus isolates representing the species Aspergillus niger, Aspergillus carbonarius, and Aspergillus japonicus in synthetic and natural grape juices was found to be a two-stage phenomenon. Several lines of evidence suggest that the first observed stage was passive, metabolism was not required, and OTA adsorption on conidia of black aspergilli could be involved. This removal was fast, without delay just after conidial inoculation both in synthetic and natural grape juices. Moreover, even nonviable, heat-treated conidia were capable of removing OTA. Finally, no OTA degradation products were detected. In the second observed stage, removal of OTA was linked to degradation by live conidia only. Ochratoxin alpha, a degradation product of OTA, was detected in the medium after incubation for 30 and 14 h for biseriate (A. niger and A. carbonarius) and uniseriate (A. japonicus) black aspergilli, respectively, when well-developed mycelium appeared. Comparisons between the three black Aspergillus isolates tested showed that A. carbonarius detoxified grape juice most effectively. However, this species often produces OTA. A. niger and A. japonicus isolates were also effective and because those species are not systematically OTA producers, they could be interesting for further OTA detoxification processes in grape juices and musts.
在合成葡萄汁和天然葡萄汁中，代表黑曲霉、炭黑曲霉和日本曲霉的黑色曲霉分离株的活分生孢子和热处理死分生孢子对赭曲霉毒素A（OTA）的生物去除是一个两阶段现象。几条证据表明，观察到的第一阶段是被动的，不需要代谢，可能涉及OTA在黑色曲霉分生孢子上的吸附。这种去除很快，在合成葡萄汁和天然葡萄汁中接种分生孢子后立即进行，没有延迟。此外，即使是无活力的热处理分生孢子也能够去除OTA。最后，未检测到OTA降解产物。在观察到的第二阶段，OTA的去除仅与活分生孢子的降解有关。当出现发育良好的菌丝体时，分别在双列（黑曲霉和炭黑曲霉）和单列（日本曲霉）黑色曲霉培养30小时和14小时后，在培养基中检测到OTA的降解产物赭曲霉毒素α。对测试的三种黑色曲霉分离株的比较表明，炭黑曲霉对葡萄汁的解毒效果最有效。然而，该菌种经常产生OTA。黑曲霉和日本曲霉分离株也有效，并且由于这些菌种不是系统性的OTA生产者，它们可能对葡萄汁和葡萄原酒中进一步的OTA解毒过程很有意义。
