Saccharomyces cerevisiae strain associated to a fish culture additive: antifungal activity and AFB1 adsorption potential

Abstract
Saccharomyces cerevisiae is widely applied as a probiotic in aquaculture activities, due to its ability to decontaminate the mycotoxin Aflatoxin B1 (AFB1). From this point, the present study aimed to evaluate the antifungal and anti-aflatoxigenic activities of inactivated Saccharomyces cerevisiae mixed with a commercial product (CP) of animal feed to assess its influence on the Aspergillus flavus and A. parasiticus fungi growth on the AFB1 production. Besides, AFB1 adsorption potential of S. cerevisiae and the commercial product was also investigated. Different concentrations of the commercial product alone and in the presence of inactivated yeast were analyzed by Aspergillus growth inhibition test, aflatoxin production by Aspergillus species, and AFB1 adsorption capacity. AFB1 detection and quantification were carried out by High-Performance Liquid Chromatography. The inactivated yeast and commercial product combination were effective in reducing A. flavus and A. parasiticus growth. A. flavusproduced less AFB1 after the inactivated yeast treatment, whereas A. parasiticus produced significantly less AFB1under a combination of inactivated yeast and 50% CP. Regarding AFB1 adsorption, 100% CP displayed the highest adsorption capacity at 10 ng mL-1 AFB1. At 25 ng mL-1 AFB1, only the treatment comprising inactivated yeast associated with 50% CP led to AFB1 adsorption, albeit at low levels. It was concluded that the association between the commercial additive and inactivated S. cerevisiae was effective in reducing the growth of fungi and there was AFB1 adsorption activity.