In vitro interactions between Aspergillus and Penicillium species associated with grape berries

Interactions between Aspergillus and Penicillium species isolated from grape berries were tested on grape juice medium, pH 5.5, at 20, 25 and 30 °C. The effect of pH was investigated on the same medium, adjusted to pH 2.9 and 3.2, at 25 °C. The species belonging to the section Nigri of the genus Aspergillus were dominant at the highest temperature, being able to grow faster than A. flavus and A. ochraceus. On the contrary, either P. brevicompactum or P. citrinum inhibited the other species at 20 °C, while at 25 °C this effect was less evident. At lower pH values P. citrinum showed strong antagonistic effects against the other tested species.