title: Diverse galactooligosaccharides consumption by bifidobacteria: implications of β-galactosidase--LacS operon.
abstract: Galactooligosaccharides (GOS) possess prebiotic properties that specifically increase the number of bifidobacteria in the human intestine, thus giving health benefits to the host. Although the bifidogenic effect of GOS has been demonstrated in numerous studies, the utilization of GOS by specific bifidobacteria remains unclear. The goal of our study was to elucidate GOS consumption by specific bifidobacteria and gain insights into the mechanism. First, we examined GOS consumption by 14 bifidobacterial strains belonging to seven different species by comparing growth rate, carbohydrate consumption, and acid production. We then performed a transcription analysis in the case of one strong GOS consumer, Bifidobacterium adolescentis YIT 4011(T), to predict the operon contributing to GOS use. The study indicated the contribution of an operon consisted of LacS symporter and β-galactosidase to bifidobacterial GOS consumption.
authors.affiliation: a Yakult Honsha European Research Center for Microbiology , Gent-Zwijnaarde , Belgium.
authors.forename: Takuya
authors.initials: T
authors.lastname: Akiyama
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Kimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hatano
mesh_terms: D000693:Anaerobiosis / Q000235:genetics; D001644:Bifidobacterium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism / Q000494:pharmacology*; D009876:Operon; D056692:Prebiotics; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D003470:Culture Media; D026901:Membrane Transport Proteins; D009844:Oligosaccharides; D056692:Prebiotics; C021499:lactose permease; D001616:beta-Galactosidase
keywords: LacS; bifidobacterium; galactooligosaccharide