In vitro study on the effect of Saccharomyces cerevisiae strains on growth and mycotoxin production by Aspergillus carbonarius and Fusarium graminearum

The effect of Saccharomyces cerevisiae RC008 and RC016 strains, previously selected based on their aflatoxin B-1 mycotoxin binding ability and beneficial properties, against Aspergillus carbonarius and Fusarium graminearum under different interacting environmental conditions was evaluated. In vitro studies on the lag phase, growth rate and ochratoxin A/zearalenone and DON production were carried out under different regimens of a(w) (0.95 and 0.99); pH (4 and 6); temperature (25 and 37 degrees C) and oxygen availability (normal and reduced). Both yeast strains showed antagonistic activity and decreasing growth rate compared to the control. In general, the RC016 strain showed the greatest inhibitory activity. Except at the interacting condition 0.95 aw, normal oxygen availability and 37 degrees C, at both pH values, A. carbonarius and F. graminearum were able to produce large amounts of mycotoxins in vitro. In general, a significant decrease in levels of mycotoxins in comparison with the control was observed. S. cerevisiae RC008 and RC016 could be considered as effective agents to reduce growth and OTA, ZEA and DON production at different interacting environmental conditions, related to those found in stored feedstuff. The beneficial and biocontrol properties of these strains are important in their use as novel additives for the control of mycotoxigenic fungi in stored feedstuffs. (C) 2012 Elsevier B.V. All rights reserved.