AFLATOXIN B sub(1) PRODUCTION BY ASPERGILLUS SECTION NIGRI STRAINS ISOLATED FROM GREEK DRIED VINE FRUITS AND COMPETITION WITH ASPERGILLUS PARASITICUS

Aflatoxin B sub(1) (AFB sub(1)) represents one of the most important food toxicants. The most important aflatoxin producers are Aspergillus flavus and A. parasiticus. Strains identified as Aspergillus section Nigri were isolated from dried vine fruits originating from Corinthos (1 strain) and Crete (3 strains). In this study, the effect of Aspergillus section Nigri strains on growth and AFB sub(1) production by A. parasiticus was investigated during 18 days of incubation in liquid Yeast Extract Sucrose medium. It was found, that Aspergillus section Nigri strains produced AFB sub(1), even at low levels. On the 12 super(th) day of incubation, which was the day of AFB sub(1) maximum production for the four strains, the AFB sub(1) levels were 98.3 - 99.9 % less than those recorded for Aspergillus parasiticus, on the same day. The AFB super(1) production by the strain of A. parasiticus on the 12 super(th) day of incubation was reduced by 97.5 % when cocultured with the strain of Aspergillus section Nigri from Corinthian dried vine fruit, whereas it was reduced by 99.9% when co-cultured with the three strains from Cretan dried vine fruits. These findings indicate that the presence of Aspergillus section Nigri strains may inhibit almost completely the AFB sub(1) production by A. parasiticus.