Saccharomyces cerevisiae strains from animal environment with in vitro aflatoxin B1 binding ability and anti-pathogenic bacterial influence

Abstract

Mycotoxins are metabolites produced by fungi growing on foods or feeds and represent a serious hazard to humans and animals. Concerns related to the negative health impact of aflatoxins have led to the investigation of strategies to prevent, eliminate or reduce the presence of these toxins in contaminated products. Saccharomyces cerevisiae strains are among promising candidates that can be used in animal feed for improving the robustness of animals in the production environment. The aim of this work was to isolate and select S. cerevisiae strains from pig environment with aflatoxin B 1 (AFB 1 ) binding ability, able to tolerate gastrointestinal conditions and with some potential beneficial properties to the host. S. cerevisiae strains were isolated from animal feed, faeces and gut and identified by morphological and molecular techniques. AFB 1 binding percentages varied among yeast strains according to the AFB 1 concentration used. The RC016 strain showed the highest adsorption percentage at the three AFB 1 concentrations tested in this work (50, 100 and 500 ng/ml) followed by RC008 strain. All yeast strains were able to survive under gastrointestinal conditions and to strongly adhere to Vero cells. All S. cerevisiae strains showed co-aggregation with pathogenic bacteria ( Escherichia coli, Enterobacter cloacae and Salmonella enterica sub sp. enterica ). Only RC016 and RC008 strongly inhibited the three pathogens assayed. S. cerevisiae strains RC016 and RC008 are promising microorganisms for inclusion in animal feed.