Four wild strains of Saccharomyces cerevisiae and the collection strain S. cerevisiae var. boulardii ATCC MYA-796 were used as test organisms to study the effect of some environmental conditions on the formation of biofilm by potentially probiotic yeasts. In a first step, the formation of biofilm was studied in four different media (YPD-Yeast Peptone Glucose; diluted YPD; 2% BP, a medium containing only bacteriological peptone; 2% GLC, a medium containing only glucose). Then, the dilution of YPD was combined with pH and temperature through a mixture design to assess the weight of the interaction of the variables; the experiments were done on S. boulardii and on S. cerevisiae strain 4. The dilution of nutrients generally determined an increased biofilm formation, whereas the effect of pH relied upon the strain. For S. cerevisiae strain 4, the highest level of sessile cells was found at pH 4-5, while S. boulardii experienced an enhanced biofilm formation at pH 6.0. Concerning temperature, the highest biofilm formation was found at 25-30 °C for both strains. The importance of this work lies in its extension of our knowledge of the effect of different environmental conditions on biofilm formation by potentially probiotic S. cerevisiae strains, as a better understanding of this trait could be an important screening tool into the selection of new multifunctional yeasts.

中文翻译：

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潜在益生菌啤酒酵母菌株的生物膜形成。

酿酒酵母的四个野生菌株和酿酒酵母的变种。boulardii ATCC MYA-796被用作测试生物，研究某些环境条件对潜在益生菌酵母形成生物膜的影响。第一步，在四种不同的培养基（YPD-酵母蛋白Y葡萄糖；稀释的YPD； 2％BP，仅含有细菌蛋白ept的培养基； 2％GLC，仅含有葡萄糖的培养基）中研究了生物膜的形成。然后，通过混合设计将YPD的稀释液与pH和温度结合起来，以评估变量相互作用的权重。该实验是在猪链球菌和啤酒酵母菌株4上进行的。营养物的稀释通常决定了生物膜形成的增加，而pH值的影响取决于菌株。对于酿酒酵母菌株4，在pH值为4-5时，无柄细胞的水平最高；而在pH 6.0时，布拉氏链球菌的生物膜形成增强。关于温度，两个菌株在25-30°C时发现了最高的生物膜形成。这项工作的重要性在于扩展了我们对不同环境条件对潜在益生菌酿酒酵母菌株在生物膜形成中的影响的了解的范围，因为更好地了解该特性可能是选择新的多功能酵母菌的重要筛选工具。 。