et al., 2006). On the contrary, in grape juice production OTA contamina-
tion may reach significant levels, since the activity of fermenting yeast
and lactic bacteria is absent (Rosa et al., 2004).
Our aim was to develop a new biocontrol approach to prevent OTA
contamination that could meet Islamic laws concerning the presence
of alcohol in halal beverages. In the present investigation, we
have selected four antagonistic yeast strains with no or low-
fermenting capacity, that are able to control the pathogenic fungus
and OTA-producer A. carbonarius in grape.
The two low-fermenting yeast strains, C. intermedia 235 and
L. thermotolerans 751, showed a significant antagonistic activity against
A. carbonarius both on grape berries and in in vitro experiments. Since
their filtrate and autoclaved filtrate culture broth were not able to
prevent consistently the pathogen growth, it is likely to assume that
the main mechanism behind the biocontrol efficiency of these strains
consists in the competition for space and nutrients rather than to the
release of diffusible antifungal compounds.