SPECIES COMPOSITION OF BLACK ASPERGILLI ON VINEYARD

BARBERIS, M.; GIAJ MERLERA, G.; CHULZE, S. N.; REYNOSO, M.M.; TORRES, A.M.

Mérida

Congreso; VI Latin American Congress of Mycotoxicology and II International Symposium on algal and fungal toxins for Industry; 2010

Sociedad Latinoamericana de Micotoxicologia

Ochratoxin A (OTA) producer fungi live as saprophytes in the superficial layer of the vineyard soil which is the main inoculum source for wine grapes. It has been demostrated that the movement of the air carries the spores from the soil to the grape surface, thus the risk of contamination with OTA in wines might be related to the presence of toxigenic strains in the soil. The information about species composition of black Aspergillus strains occurring on vineyards soil is limited; moreover the accurate identification of Aspergillus species in the section Nigri is important because both the fungi presence and the toxin profiles of each species define potential risk for OTA contamination.The aim of this work was to evaluate the black Aspergillus inoculum potential in vineyard soils from different wine-producing regions of Argentina using classic and molecular methodology to identify the strains; to determine the toxigenic capacity of the strains isolated, and to relate the frequency of isolation of the Aspergillus section Nigri species with the environmental conditions. In general, all the strains isolated belonging to Aspergillus section Nigri showed low capacity to produce OTA. The main ochratoxigenic species, A. carbonarius, was isolated in low frequency. Biodiversity and distribution of Aspergillus section Nigri species depend on the environmental factors. We can conclude that temperature and altitude are the main factors influencing the presence of OTA producers, while rain levels are less important. From the results found we could infer low levels of OTA in wine in Argentina.Ochratoxin A (OTA) producer fungi live as saprophytes in the superficial layer of the vineyard soil which is the main inoculum source for wine grapes. It has been demostrated that the movement of the air carries the spores from the soil to the grape surface, thus the risk of contamination with OTA in wines might be related to the presence of toxigenic strains in the soil. The information about species composition of black Aspergillus strains occurring on vineyards soil is limited; moreover the accurate identification of Aspergillus species in the section Nigri is important because both the fungi presence and the toxin profiles of each species define potential risk for OTA contamination.The aim of this work was to evaluate the black Aspergillus inoculum potential in vineyard soils from different wine-producing regions of Argentina using classic and molecular methodology to identify the strains; to determine the toxigenic capacity of the strains isolated, and to relate the frequency of isolation of the Aspergillus section Nigri species with the environmental conditions. In general, all the strains isolated belonging to Aspergillus section Nigri showed low capacity to produce OTA. The main ochratoxigenic species, A. carbonarius, was isolated in low frequency. Biodiversity and distribution of Aspergillus section Nigri species depend on the environmental factors. We can conclude that temperature and altitude are the main factors influencing the presence of OTA producers, while rain levels are less important. From the results found we could infer low levels of OTA in wine in Argentina.