Sugar Transport Systems of<i> Bifidobacterium longum </i>NCC2705

Abstract

Here we present the complement of the carbohydrate uptake systems of the strictly anaerobic probiotic Bifidobacterium longum NCC2705. The genome analysis of this bacterium predicts that it has 19 permeases for the uptake of diverse carbohydrates. The majority belongs to the ATP-binding cassette transporter family with 13 systems identified. Among them are permeases for lactose, maltose, raffinose, and fructooligosaccharides, a commonly used prebiotic additive. We found genes that encode a complete phosphotransferase system (PTS) and genes for three permeases of the major facilitator superfamily. These systems could serve for the import of glucose, galactose, lactose, and sucrose. Growth analysis of NCC2705 cells combined with biochemical characterization and microarray data showed that the predicted substrates are consumed and that the corresponding transport and catabolic genes are expressed. Biochemical analysis of the PTS, in which proteins are central in regulation of carbon metabolism in many bacteria, revealed that B. longum has a glucose-specific PTS, while two other species (Bifidobacterium lactis and Bifidobacterium bifidum) have a fructose-6-phosphate-forming fructose-PTS instead. It became obvious that most carbohydrate systems are closely related to those from other actinomycetes, with a few exceptions. We hope that this report on B. longum carbohydrate transporter systems will serve as a guide for further in-depth analyses on the nutritional lifestyle of this beneficial bacterium.

Characterization of a Novel β-l-Arabinofuranosidase in Bifidobacterium longum

“…B. longum JCM 1217 encodes a number of candidates for the ␣-L-arabinofuranosidase gene, 11 members of the GH43 gene family, and 4 members of the GH51 gene family. Several reports indicate that B. longum has the ability to grow on L-arabinose and ␣-L-arabinooligosaccharides (14,23,(25)(26)(27). We showed that B. longum also uses ␤-Ara 2 as a carbohydrate source (supplemental Table S4).…”

Sugar source modulates exopolysaccharide biosynthesis in Bifidobacterium longum subsp. longum CRC 002

“…Lactose is preferred over glucose by B. longum subsp. longum NCC2705, as suggested by transcriptional repression of glpP, a glucose uptake gene (Parche et al, 2007). As a disaccharide, lactose provides glucose for glycolysis as well as galactose that can be shunted directly to the Leloir pathway for sugar nucleotide biosynthesis.…”

“…In addition, there are at least three permease systems in B. longum subsp. longum NCC2705 that are active for lactose uptake, while glucose is transported by two systems, of which the phosphotransferase is transcribed at a low level (Parche et al, 2007). In order to determine whether the differences in EPS production between cultures of B. longum subsp.…”

Structural and Thermodynamic Analyses of Solute-binding Protein from Bifidobacterium longum Specific for Core 1 Disaccharide and Lacto-N-biose I

“…On the other hand, the K d value for LNT was much larger, being 11 M. Therefore, we conclude that BL1638 -1640 is an ABC transporter specific for disaccharides GNB and LNB. Although this operon lacks a nucleotide-binding domain, it is likely that a universal nucleotide-binding domain (BL0673) energizes the sugar-transporting system (21). Colonization of adult human intestine by Bifidobacteria is thought to involve the recognition and metabolism of mucin glycans (72,73).…”

“…BL1638 is also thought to be a membrane-anchored lipoprotein, because its primary structure contains a lipid-anchor signal sequence, GLAGCG. In the genome of B. longum NCC2705, there are 13 putative ABC transporter systems for the uptake of sugars (21). However, there are no reports on the three-dimensional structures of sugar transporters from Bifidobacteria and their substrate recognition mechanisms.…”