CSIR-Institute of Microbial Technology, Chandigarh, India.
Sci Rep. 2017 Mar 23;7(1):371. doi: 10.1038/s41598-017-00414-2.
The probiotic yeast, Saccharomyces boulardii (Sb) is known to be effective against many gastrointestinal disorders and antibiotic-associated diarrhea. To understand molecular basis of probiotic-properties ascribed to Sb we determined the complete genomes of two strains of Sb i.e. Biocodex and unique28 and the draft genomes for three other Sb strains that are marketed as probiotics in India. We compared these genomes with 145 strains of S. cerevisiae (Sc) to understand genome-level similarities and differences between these yeasts. A distinctive feature of Sb from other Sc is absence of Ty elements Ty1, Ty3, Ty4 and associated LTR. However, we could identify complete Ty2 and Ty5 elements in Sb. The genes for hexose transporters HXT11 and HXT9, and asparagine-utilization are absent in all Sb strains. We find differences in repeat periods and copy numbers of repeats in flocculin genes that are likely related to the differential adhesion of Sb as compared to Sc. Core-proteome based taxonomy places Sb strains along with wine strains of Sc. We find the introgression of five genes from Z. bailii into the chromosome IV of Sb and wine strains of Sc. Intriguingly, genes involved in conferring known probiotic properties to Sb are conserved in most Sc strains.
益生菌酵母布拉氏酵母菌（Sb）已被证实对多种胃肠道疾病和抗生素相关性腹泻有效。为了了解赋予 Sb 益生菌特性的分子基础，我们测定了 Biocodex 和 unique28 这两个 Sb 菌株的全基因组以及另外三个在印度作为益生菌销售的 Sb 菌株的草图基因组。我们将这些基因组与 145 株酿酒酵母（Sc）进行了比较，以了解这些酵母之间在基因组水平上的相似性和差异。Sb 与其他 Sc 的一个显著区别是缺乏 Ty 元件 Ty1、Ty3、Ty4 和相关的 LTR。然而，我们可以在 Sb 中识别出完整的 Ty2 和 Ty5 元件。所有 Sb 菌株都缺乏己糖转运蛋白 HXT11 和 HXT9 的基因以及天冬酰胺利用基因。我们发现絮凝素基因的重复周期和重复次数存在差异，这可能与 Sb 与 Sc 相比的差异粘附有关。基于核心蛋白质组的分类法将 Sb 菌株与 Sc 的葡萄酒菌株放在一起。我们发现有五个来自 Z. bailii 的基因从 Sb 的染色体 IV 中导入 Sc 的葡萄酒菌株。有趣的是，赋予 Sb 已知益生菌特性的基因在大多数 Sc 菌株中都保守。
