A new semi-selective medium for the ochratoxigenic fungus Aspergillus carbonarius

Aspergillus carbonarius (Bainier) Thom. and Aspergillus niger Van Tieghem are common fungal contaminants of several commodities, including grapes. A. carbonarius is the most important, if not the exclusive, responsible for wine contamination by ochratoxin A (OTA) in Mediterranean areas. Identification of A. carbonarius is made difficult by its high similarity with A. niger, the Aspergillus species most common on grapes, as well as with other species of the section Nigri of this genus. Hence, it requires deep knowledge of fungal taxonomy. A semi-selective medium based on Malt Extract Agar amended with appropriate antibiotics (chloramphenicol and chlorretracycline) and fungicides (dichloran and boscalid) was developed in order to speed up the quantitative detection of A. carbonarius in grapes and musts and improve risk assessment of OTA contamination in wine