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Aims: (i) To determine the aflatoxin B1 (AFB1) adsorption and desorption dynamics in the presence of Lactobacillus rhamnosus RC007 under simulated transit of AFB1 at each gastrointestinal tract (GIT—saliva, stomach and intestine) stage consecutively and then, separately, (ii) to study the ability of L. rhamnosus RC007 to biotransform AFB1 as a strategy that complements the adsorption process. Methods and Results: The AFB1 adsorption and desorption assay simulating the GIT passage of AFB1 (93·89 ng g−1) in the presence of L. rhamnosus RC007 (108CFU per ml) was conducted. Moreover, lactic acid production was determined. Results demonstrated that predominant environmental conditions in salivary solution induced a low AFB1 adsorption, while the transit through the gastric solution and intestinal solution allowed high percentages of adsorption and did not generate significant AFB1 desorption. Conclusions: The AFB1 adsorption and desorption dynamics in the presence of L. rhamnosus RC007 was favoured by gastric and intestinal environment. Significance and Impact of the Study: The knowledge of the adsorption dynamics of AFB1 with a micro‐organism of interest will allow predicting its behaviour at each stage of the GIT. [ABSTRACT FROM AUTHOR]

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]

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B1 binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B1 production were carried out in vitro under different regimes of a w (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB1 in vitro. A significant decrease of AFB1 levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400 ng ml−1. S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB1 production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed. [ABSTRACT FROM AUTHOR]

The aim was to evaluate both the ability of yeast strains to survive and bind AFB1under ruminant gastrointestinal conditions and the effect of these yeast strains on ruminal fermentation. Yeast viability was studied under simulated gastrointestinal conditions. AFB1binding ability was evaluated at different pH values as present in the ruminant gastrointestinal tract. The effect of yeast strains on cellulose digestion and volatile fatty acids production by ruminal bacteria was also evaluated. All yeast strains were able to survive under gastrointestinal conditions and to adsorb AFB1at the different pH assayed. The strain RC016 showed the highest binding percentage at the three tested pH. The number of cellulolytic bacteria in ruminal fluid increased in the presence of RC008 and RC016 yeast strains. The concentration of acetate and propionate after ruminal fermentation increased with the addition of RC008 and RC016 strains; this effect was less significant with RC009 strain. Strains RC008 and RC016 are potential probiotic to be included in animal feed: they help to increase fibber digestibility and could reduce AFB1bioavailability in the gastrointestinal tract. ViableS. cerevisiaeRC008 and RC016 strains with both probiotic and mycotoxins adsorption properties could be used as feed additives in ruminant feedstuff. [ABSTRACT FROM AUTHOR]

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]