Dynamics of Aspergillus and Penicillium species in different Italian vineyards

Samples of grape clusters were collected throughout the Italian territory from Piedmont to Sicily in order to investigate their fungal community with particular reference to toxigenic species. Despite the wide variations observed in the contamination levels, the average number of CFU/g of fresh weight was higher in samples collected in Southern and Central Italy, while fungal communities detected in Northern regions and in Sardinia were generally more reduced. Black Aspergilli and in particular A. carbonarius, were isolated in all the sampling areas, but were more frequent and abundant in Southern Italy. A. ochraceus, even if not frequently isolated, was present all over the Itailan contry as well as A. flavus. Several Aspergillus species were seldom detected in different areas. The most commnly isolated Penicillium species, particularly frequent in Northern Italy, were P. brevicompactum, P. citrinum and P. expansum. Few strains of A. carbonarius isolated from all the sampled regions, except from Sardinia, produced OTA in vitro. Some isolates of other species belonging to the Nigri group accumulated OTA in vitro. OTA was produced by almost all the A. ochraceus isolates and synthetized also by some Eurotium strains, A. terreus, P. aurantiogriseum, P. expansum and P. variabile. OTA, not found in samples collected in Northern Italy, contaminated very few samples, coming from Central Italy, Sicily and Sardinia. More than 70 % of samples collected in Southern italy contained variable quantity of OTA.