Related Experiment Video
Updated: Jun 3, 2026

Analysis of Interactions between Endobiotics and Human Gut Microbiota Using In Vitro Bath Fermentation Systems
Published on: August 23, 2019
Metabolism of a plant derived galactose-containing polysaccharide by Bifidobacterium breve UCC2003
Mary O'Connell Motherway1, Gerald F Fitzgerald, Douwe van Sinderen
1Alimentary Pharmabiotic Centre, National University of Ireland, Cork, Western Road, Cork, Ireland.
Abstract:
In this study, we describe the functional characterization of the Bifidobacterium breve UCC2003 gal locus, which is dedicated to the utilization of galactan, a plant-derived polysaccharide. Using a combination of molecular approaches we conclude that the galA gene of B. breve UCC2003 encodes a β-1,4-endogalactanase producing galacto-oligosaccharides, which are specifically internalized by an ABC transport system, encoded by galBCDE, and which are then hydrolysed to galactose moieties by a dedicated intracellular β-galactosidase, specified by galG. The generated galactose molecules are presumed to be fed into the fructose-6-phosphate phosphoketolase pathway via the Leloir pathway, thereby allowing B. breve UCC2003 to use galactan as its sole carbon and energy source. In addition to these findings we demonstrate that GalR is a LacI-type DNA-binding protein, which not only appears to control transcription of the galCDEGR operon, but also that of the galA gene.
Related Concept Videos
Biosynthesis of Polysaccharides
Carbohydrate Metabolism
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Overview of Carbohydrate Metabolism
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
Production of Alcohol
Overview of Metabolism
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
Cellulose and Pectic Polysaccharides
As a cell matures, its cell wall specializes according to its type. For example, the parenchyma cells of...
