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Aim To evaluate the ability of probiotic Saccharomyces cerevisiae RC016 strain to reduce fumonisin B1 ( FB1) in vitro and to optimize the culture conditions for the growth of the yeast employing surface response methodology. Methods and Results Using Plackett-Burman screening designs ( PBSD) and central composite designs ( CCD), an optimized culture medium containing (g l−1) fermentable sugars provided by sugar cane molasses ( CMs), yeast extract ( YE) and ( NH4)2 HPO4 ( DAP) was formulated. The S. cerevisiae RC016 strain showed the greatest binding at all assayed FB1 concentration. The CMs, YE, DAP concentrations and incubation time influenced significantly the biomass of S. cerevisiae RC016. Conclusion A combination of CMs 17%; YE 4·61 g l−1 and incubation time 60 h was optimum for maximum biomass of S. cerevisiae RC016. Significance and Impact of the Study The importance of this work lies in the search for live strains with both probiotic and fumonisin B1 decontamination properties that could be sustainably produced in a medium just containing cheap carbon, nitrogen and phosphorus sources and would be included in a novel product to animal feed. [ABSTRACT FROM AUTHOR]

Aims: To examine Saccharomyces cerevisae strains with previously reported beneficial properties and aflatoxin B1 binding capacity, for their ability to remove ochratoxin A (OTA) and zearalenone (ZEA) and to study the relation between cell wall thickness and detoxificant ability of yeast strains. Methods and Results: A mycotoxin binding assay at different toxin concentrations and the effect of gastrointestinal conditions on mycotoxin binding were evaluated. Ultrastructural studies of yeast cells were carried out with transmission electronic microscopy. All tested strains were capable of removing OTA and ZEA. Saccharomyces cerevisiae RC012 and RC016 showed the highest OTA removal percentage, whereas RC009 and RC012 strains showed the highest ZEA removal percentages. The cell diameter/cell wall thickness relation showed a correlation between cell wall amount and mycotoxin removal ability. After exposure to gastrointestinal conditions, a significant increase in mycotoxin binding was observed. Conclusions: All tested Saccharomyces cerevisiae strains were able to remove OTA and ZEA, and physical adsorption would be the main mechanism involved in ochratoxin A and ZEA removal. Gastrointestinal conditions would enhance adsorption and not decrease mycotoxin-adsorbent interactions. Significance and Impact of the Study: Live strains with mycotoxin binding ability and beneficial properties are potential probiotics that could be included in animal feed. Previous and present results suggest that the RC008 and RC016 strains are very promising candidates for functional feed product development. [ABSTRACT FROM AUTHOR]

Abstract: The gut associated lymphoid tissue (GALT) is anatomical and functionally divided in inductive and effectors sites. In previous works we demonstrated that non-pathogenic bacteria with probiotic characteristics can improve the gut mucosal immune system, with an increase in the number of IgA and cytokines producing cells in the effector site of the intestine. In the present work we studied the effect of non-pathogenic Gram(+), Gram(−) bacteria and a Gram(+) probiotic strain on the inductor site (PP) after the oral administration to BALB/c mice. We also studied some signals induced by the assayed strain in the effectors site, such as the enzyme calcineurin and TLR-9 as a way to understand the mechanisms induced in such bacterial stimulation. The implicance of the lipoteichoic acid (LTA) in the immunostimulation was analyzed. All strains increased the number of IFN-γ and TNF-α(+) cells, but not of IL-10(+) cells in the total population of PP. The release of IFN-γ and TNF-α was only induced by LPS stimulation. All assayed strains increased the number of calcineurin(+) cells, while only Gram(+) strains increased the number of TLR-9(+) cells. The immunostimulatory properties of the purified LTA from Gram(+) strains was evaluated on a monocyte–macrophage U937 cell line. These cells showed capacity to release TNF-α and IL-10 in response to all LTA assayed in a dose-dependent way. Gram(+) strains induced signals through the calcineurin enzyme able to activate the transcriptional factor NFAT and through TLR-9. The LTA molecule from Gram(+) strains would not be the only structure involved in the immunostimulatory properties observed, specially for the probiotic strain. [Copyright &y& Elsevier]

Aim To evaluate the ability of probiotic Saccharomyces cerevisiae RC016 strain to reduce fumonisin B1 ( FB1) in vitro and to optimize the culture conditions for the growth of the yeast employing surface response methodology. Methods and Results Using Plackett-Burman screening designs ( PBSD) and central composite designs ( CCD), an optimized culture medium containing (g l−1) fermentable sugars provided by sugar cane molasses ( CMs), yeast extract ( YE) and ( NH4)2 HPO4 ( DAP) was formulated. The S. cerevisiae RC016 strain showed the greatest binding at all assayed FB1 concentration. The CMs, YE, DAP concentrations and incubation time influenced significantly the biomass of S. cerevisiae RC016. Conclusion A combination of CMs 17%; YE 4·61 g l−1 and incubation time 60 h was optimum for maximum biomass of S. cerevisiae RC016. Significance and Impact of the Study The importance of this work lies in the search for live strains with both probiotic and fumonisin B1 decontamination properties that could be sustainably produced in a medium just containing cheap carbon, nitrogen and phosphorus sources and would be included in a novel product to animal feed. [ABSTRACT FROM AUTHOR]