El residuo de levaduras de la fermentación cervecera como aditivo en alimentación animal con potencial probiótico

SOFIA SAMPAOLESI; GRACIELA L. DE ANTONI

San Carlos de Bariloche

Workshop; International Workshop on Brewing Yeasts; 2021

IPATEC COMAHUE

The brewing industry produces major amounts of solid wastes, such as the brewing fermentation residue (BFR), an organic waste with high nutritional value, whose disposal without treatment attaches environmental damage. In this context, the aim of this study was the characterization of antibacterial, antifungal and mycotoxin binding properties of yeasts isolated from BRF, with prospects of its valorization as a feed additive for broilers. Isolated yeasts from M6 BRF, identified as Pichia kudriavzevii MBELGA61 and Saccharomyces cerevisiae MBELGA62, are able to survive the broilers?s gastrointestinal conditions and co-aggregate with Escherichia coli and Salmonella Enteritidis. These zoonotic pathogens provoke broilers´ death, causing significant economic losses.Additionally, the BFRs containing both yeast, effectively decreased the growth rate of Aspergillus flavus and parasiticus (mycotoxigenic fungi commonly found in feed and raw materials) from 0,0341 to 0,0146 cm/h and from 0,0387 to 0,0175 cm/h, respectively. Moreover, brewer´s yeast cell-free supernatants proved the ability to diminish fungal germination and the yeasts synthesize volatile metabolites with antifungal effect, especially P. kudriavzevii MBELGA61. The volatile compounds extended the fungal lag phase more than 100% and reduced fungal growth rates from 0,0312 to 0,017 cm/h for A. flavus and from 0,032 to 0,018 cm/h for A. parasiticus. In addition, the aflatoxin B1 (AFB1) binding ability of brewer?s yeasts was studied. This tumorigenic mycotoxin, produced by several Aspergillus sp. strains, was 79.0% adsorbed by the BRFs. The BRF-toxin complex retained more than 50% of the original aflatoxin present in a AFB1 suspension, after passing through the simulated broiler?s gastrointestinal tract. This investigation provided strong evidence that brewer?s yeasts are effective Aspergillus sp. biocontroller and AFB1 detoxifying agents, with probiotic potential to be used as feed additives.