A bile-inducible membrane protein mediates bifidobacterial bile resistance.
Bottom Line: The high level of similarity to bile efflux pumps from other bifidobacteria suggests a significant and general role for Bbr_0838 in bile tolerance.Insertional inactivation of Bbr_0838 in B. breve UCC2003 resulted in a strain, UCC2003:838(800) , which exhibited reduced survival upon cholate exposure as compared with the parent strain, a phenotype that was reversed when a functional, plasmid-encoded Bbr_0838 gene was introduced into UCC2003:838(800) .This study represents the first in-depth analysis of a bile-inducible locus in bifidobacteria, identifying a key gene relevant for bifidobacterial bile tolerance.
Affiliation: Departamento de Microbiología y Bioquímica de Productos Lácteos, Instituto de Productos Lácteos de Asturias, Villaviciosa, Asturias, Spain.Show MeSH
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Mentions: In order to show that the reduced bile survival phenotype in the insertion mutant was due to the absence of functional Bbr_0838, we complemented UCC2003::838800 strain with a plasmid containing the structural gene. Complementation of UCC2003::838800 with Bbr_0838 expressed from its own promoter on pBC1.2 restored the growth in the presence of cholate and the bile resistant phenotype to levels comparable with wild‐type B. breve UCC2003 (Fig. 4B).
Affiliation: Departamento de Microbiología y Bioquímica de Productos Lácteos, Instituto de Productos Lácteos de Asturias, Villaviciosa, Asturias, Spain.