Biodegradation of ochratoxin A by Aspergillus section Nigri species isolated from French grapes:a potential means of ochratoxin A decontamination in grape juices and musts

摘要

Ochratoxin A (OTA) is a very dangerous mycotoxin, the presence of which is often reported in different foods, as well as in beverages such as grapes, grape juices and\udwines. Detoxifying these products is therefore of prime importance in protecting consumer health, and biological approaches have been the most promising\udmethods. In this report, 40 isolates representing the black apergilli species Aspergillus carbonarius, A. niger aggregate and A. japonicus, isolated on French\udgrapes, were assessed for OTA degradation capacities in CZAPEK yeast extract broth (CYB) and in a synthetic grape juice medium (SGM) contaminated with\udOTA at 2 mg L1 (5 mM). It was clearly observed that in both media these fungi had the ability to degrade OTA to OTa (ochratoxina). However, there were differences\udbetween the media used and species tested during OTA degradation. In SGM and CYB, 77% and 45% of the isolates, respectively were able to degrade more than\ud80% of the OTA. Despite a better growth on SGM, specific OTA degradation was higher on CYB for most of the isolates. Kinetic studies carried out on SGM with\udthree black Aspergillus isolates all showed different OTA degradation rates. After 9 days of incubation, OTa had decreased, whereas an unknown compound\udappeared. A. niger could be the first interesting species for OTA detoxification processes, followed by A. japonicus.