title: Genotypic and physiological characterization of Saccharomyces boulardii, the probiotic strain of Saccharomyces cerevisiae.
abstract: Saccharomyces boulardii, a yeast that was isolated from fruit in Indochina, has been used as a remedy for diarrhea since 1950 and is now a commercially available treatment throughout Europe, Africa, and South America. Though initially classified as a separate species of Saccharomyces, recent publications have shown that the genome of S. boulardii is so similar to Saccharomyces cerevisiae that the two should be classified as conspecific. This raises the question of the distinguishing molecular and phenotypic characteristics present in S. boulardii that make it perform more effectively as a probiotic organism compared to other strains of S. cerevisiae. This investigation reports some of these distinguishing characteristics including enhanced ability for pseudohyphal switching upon nitrogen limitation and increased resistance to acidic pH. However, these differences did not correlate with increased adherence to epithelial cells or transit through mouse gut. Pertinent characteristics of the S. boulardii genome such as trisomy of chromosome IX, altered copy number of a number of individual genes, and sporulation deficiency have been revealed by comparative genome hybridization using oligonucleotide-based microarrays coupled with a rigorous statistical analysis. The contributions of the different genomic and phenotypic features of S. boulardii to its probiotic nature are discussed.
authors.affiliation: Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Edwards-Ingram
authors.forename: Paul
authors.initials: P
authors.lastname: Gitsham
authors.forename: Nicola
authors.initials: N
authors.lastname: Burton
authors.forename: Geoff
authors.initials: G
authors.lastname: Warhurst
authors.forename: Ian
authors.initials: I
authors.lastname: Clarke
authors.forename: David
authors.initials: D
authors.lastname: Hoyle
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Oliver
authors.forename: Lubomira
authors.initials: L
authors.lastname: Stateva
mesh_terms: D000143:Acids / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D002448:Cell Adhesion; D015825:Chromosomes, Fungal / Q000235:genetics; D015169:Colony Count, Microbial; D025141:Drug Resistance, Fungal; D018628:Gene Dosage; D016681:Genome, Fungal; D025301:Hyphae / Q000254:growth & development; D008853:Microscopy; D009584:Nitrogen / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D019936:Probiotics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D013172:Spores, Fungal; D014314:Trisomy / Q000235:genetics
chemical_list: D000143:Acids; D000935:Antifungal Agents; D009584:Nitrogen