Saccharomyces cerevisiae From Silage Inhibit Fusarium graminearum Growth And Zearalenona Production

DOGI, C; ARMANDO, MR; POLONI, V; DALCERO, AM; CAVAGLIERI, LR

Mendoza

Congreso; Congreso ISM 2011; 2011

Agricultural activities involve daily use of maize silage as feed for livestock, which can be contaminated by mycotoxigenic molds. Fusarium graminearum is commonly found on cereal grains and greatly decreases yield and seed quality, and produces mycotoxins: deoxynivalenol (DON) and zearalenone (ZEA). Zearalenone and its derivatives are an important class of endocrine disrupters, which can cause estrogenic effects and alterations in the reproductive tract of laboratory and domestic animals. An interesting approach for mycotoxin decontamination in feedstuff is the use of functional food that contain beneficial microorganisms, that may bind mycotoxins in the gastrointestinal tract (GIT), thus reducing the extent of their adsorption and systemic toxicity. Food and feed are very diverse microbial growth substrates, due to variation in intrinsic factors such as pH, nutrients and water activity (aw), and extrinsic factors such as storage temperature. The aim of this work was to study the effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B1 (AFB1) binding ability and antagonistic substances production, against F. graminearum under different interacting environmental conditions. Studies on the lag phase, growth rate and ZEA production were carried out in vitro under different regimes of aw (0.95 and 0.99); pH (4 and 6); temperature (25 and 37°C) and oxygen availability (normal and reduced). No fungal growth was observed at 37°C. The RC016 strain showed total inhibition of fungal growth at all assayed conditions, whereas RC008 strain showed antagonistic activity only at pH4. Fusarium graminearum was able to in vitro produce large amounts of ZEA. The data show that S. cerevisiae RC008 and RC016 could exert their role as biological control agents for F. graminearum in a wide range of environmental conditions, according to that found in stored feedstuff.