Aspergillus niger has been recently found to produce fumonisin B(2) (FB(2)). Thirty-one strains belonging to four Aspergillus species isolated from grape were evaluated for FB(2) production on agar plates. Four out of eight strains of A. niger produced FB(2) (29-293 microg g(-1)). None of the strains of A. uvarum (n = 7), A. tubingensis (8) and A. carbonarius (8) produced detectable amounts of toxin. The capability to produce FB(2) was also confirmed by some A. niger strains artificially inoculated on grape berries. Natural occurrence of FB(2), at levels of 0.01 and 0.4 microg ml(-1), was found in two samples of must collected in Apulian cellars in 2007. This is the first report of FB(2) contamination in must. These findings suggest that there is a potential risk of exposure to FB(2) in the grape-wine chain for consumers and that A. niger may represent the major fumonisin-producing species among black Aspergilli occurring on grapes.

Fumonisins are mycotoxins with cancerpromoting activity and are associated with a number of animal and human diseases. The potential risk of contamination by fumonisin B 2 (FB 2 ), although at low levels, has been demonstrated in must and wine. Black aspergilli in general and Aspergillus niger in particular are considered to be the major responsible agents of FB 2 contamination in grape and its by-products. Contamination by FB 2 therefore is yet another safety concern of grape and wine producers, as ochratoxin A, produced mainly by A. carbonarius, may prove to be a major mycotoxicological problem in the grape-wine chain.