Characterization of exopolysaccharides produced by Bifidobacterium longum NB667 and its cholate-resistant derivative strain IPLA B667dCo.
Bifidobacteria are natural members of the human intestinal microbiota and some strains are being used as probiotics. Adaptation to bile can allow them to increase survival in gastrointestinal conditions, thus improving their viability. Bifidobacterium longum NB667 and the cholate-resistant strain B. longum IPLA B667dCo produced exopolysaccharides (EPS) that were partially characterized. Analysis by size exclusion chromatography-multiangle laser light scattering indicated that the EPS crude fractions of both strains contained two polymer peaks of different molar mass. On the basis of chromatographic techniques both peaks appeared to be heteropolysaccharides. The smaller peak was mainly composed of glucose, galactose and rhamnose whose molar ratios and linkage types showed slight variations between the EPS fractions of both strains. The bigger peak consisted of glucose and galactose; the monosaccharide composition was identical in the EPS fractions of the two microorganisms, but their infrared spectra presented some differences regarding compounds other than carbohydrates that seem to be associated to the polymer. Differences in the composition of EPS fractions did not affect the capability of crude EPS from B. longum to be fermented by the human intestinal microbiota in fecal batch cultures.
Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Departamento de Microbiología y Bioquímica de Productos Lácteos, Asturias, Spain.
Nuria
N
Salazar
Patricia
P
Ruas-Madiedo
Alicia
A
Prieto
Luis P
LP
Calle
Clara G
CG
de Los Reyes-Gavilán
D001644:Bifidobacterium / Q000187:drug effects / Q000378:metabolism*; D020355:Cholates; D002850:Chromatography, Gel; D024881:Drug Resistance, Bacterial; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D005690:Galactose / Q000032:analysis; D005947:Glucose / Q000032:analysis; D006801:Humans; D007422:Intestines / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry
D020355:Cholates; D011135:Polysaccharides, Bacterial; D005947:Glucose; D005690:Galactose