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Bifidobacteria are one of the main microbial inhabitants of the human colon. Usually administered in fermented dairy products as beneficial microorganisms, they have to overcome the acidic pH found in the stomach during the gastrointestinal transit to be able to colonize the lower parts of the intestine. The mechanisms underlying acid response and adaptation in Bifidobacterium longum biotype longum NCIMB 8809 and its mutant resistant to acid pH B. longum biotype longum 8809dpH, were studied. Comparison of protein maps, and protein identification by MALDI-TOF mass spectrometry analysis, allowed us to identify 9 different proteins whose production largely changed in the mutant strain. Furthermore, the production of 47 proteins was modulated by pH in one or both strains. These included general stress response chaperones, proteins involved in transcription and translation, as well as in the carbohydrate and nitrogen metabolism, among others. Significant differences in the levels of metabolic end-products and in the redox status of the cells were also detected between the wild type strain and its acid pH resistant mutant in response, or as a result of, adaptation to acid. Remarkably, the results of this work indicated that adaptation and response to low pH in B. longum biotype longum involves changes in the glycolytic flux and in the ability to regulate the internal pH. These changes were accompanied by a higher content of ammonium in the cytoplasm, likely coming from amino acid deamination, and a decrease of the bile salt hydrolase activity ; This work was financed by European Union FEDER funds and the Spanish Plan Nacional de I + D (project AGL2004-06727-C02-01/ALI and AGL2005-05788-C02-01/ALI). B. Sánchez was the recipient of a FPI predoctoral fellowship from the Spanish Ministerio de Ciencia y Tecnología and from the MICA department of the National Institute for Research in Agronomy (INRA). ; Peer reviewed

Als herausragendes Beispiel mittelalterlicher Bibliothekskataloge gilt der um 1475 angelegte Katalog der Erfurter Kartause. Für ihn entstand zeitgleich ein einführendes Prohemium longum. Das Prohemium longum ist ein wichtiger Text geistlicher Literatur und erweist sich als bedeutender Beitrag zum Verständnis kartäusischer Spiritualität am Ausgang des Mittelalters. Die vorliegende Arbeit liefert die erstmalige und vollständige Edition seines lateinischen Texts. Ergänzt wird diese mit Untersuchungen zu Fragen des Textverständnisses: Was weiss man über den Verfasser? Mit welcher Intention schrieb er? Ein Kapitel widmet sich der Kompilationsmethode, mit der das Prohemium verfasst wurde, ein weiteres der Darstellungsweise. Schliesslich gehen drei umfangreiche Abschnitte zentralen Begriffen des Texts und deren zeitgenössischer Bewertung nach: ignorancia, theologia mistica und lectio et studium.

Extracellular proteins of Bifidobacterium longum may mediate important interactions with the host. Here, we report on a comprehensive analysis of such proteins by using protein-free culture conditions and two-dimensional gel electrophoresis followed by mass spectrometry for protein identification. Seventeen proteins were detected in the culture supernatant, and 14 of them could be identified. Among these were 3 hypothetical solute-binding proteins of ABC transporters, an invasion-associated protein homolog, putative enzymes catalyzing cell wall turnover, several polypeptides with similarity to bacterial conjugation proteins, and 3 proteins of unknown function. Surprisingly, aldolase, usually considered as a cytoplasmic protein, was found in the culture supernatant. All proteins, excluding aldolase, were predicted to contain a signal peptide and a signal peptide cleavage site in their immature form. Some of the excreted proteins are interesting targets for further genetic and physiological studies ; This work was financed by European Union FEDER funds and the Spanish Plan Nacional de I+D (project AGL2004-06727-C02). B.S. was the recipient of a pre-doctoral fellowship from the Spanish Ministerio de Ciencia y Tecnologia and from the MICA Department of the National Institute for Research in Agronomy (INRA) ; Peer reviewed

Stable isotope labeling of amino acids in cell culture was used for Bifidobacterium longum. A comprehensive proteomic strategy was developed and validated by designing an appropriate semidefined medium that allows stable replacement of natural leucine by [13C6]leucine. Using this strategy, proteins having variations of at least 50% in their expression rates can be quantified with great confidence ; This work was financed by European Union FEDER funds and the Spanish Plan Nacional de I + D (project AGL2004-06727-C02-01/ALI and fellowship PR2006-0421) and by the Swiss National Science Foundation (grant 3100-A0-104214). ; Peer reviewed

The molecular-genetic analysis of the bacterial genome of the strain B. longum BIM B-813D distinguished by a high level of β-galactosidase production was performed. Genes Bgal_small_N, lacZ1, bgaB1, bgaB2 and bgaB3, and lacZ2, encoding the synthesis of β-galactosidases, were revealed in the deciphered genome. It was shown that the genes lacZ1, bgaB2, and bgaB3 characterized by an enhanced degree of similarity to the genes of closely related bifidobacterial species, presumably code for the enzymes catalyzing the specific reactions of hydrolysis and transglycosylation of carbohydrates. It was found that the enzymes BgaB1, BgaB2 and BgaB3 belong to the GH42 family of glycosyl hydrolases, whereas the enzymes LacZ1 and LacZ2 – to the GH2 family. The genome domains responsible for the synthesis of β-galactosidases in the strain B. longum BIM B-813D were studied in detail. A comparative analysis of the locus of lacZ1 in B. longum BIM B-813D and the similar genome fragment AS143_01230 from B. longum subsp. longum MC-42 detected the presence of the transposase gene ISL3 in the former strain. It was suggested that the insertion of the sequence of ISL3 in the lacZ1 locus resulted in the modified gene expression and the increased production of β-galactosidase in the strain B. longum BIM B-813D.

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. © 2012 American Chemical Society. ; This work was financially supported by the European Union FEDER funds and by the Plan Nacional de I + D under projects AGL2004-6088, AGL2007-62736, and AGL2010-16525. ; Peer Reviewed

Bifidobacterium longum can be isolated from human faeces, some strains being considered probiotics. B. longum NIZO B667 produces an exo-acting α-L-arabinofuranosidase, AbfB, previously purified by us, that releases L-arabinose from arabinan and arabinoxylan. This activity was subjected to two-seven-fold induction by L-arabinose, D-xylose, L-arabitol and xylitol and to repression by glucose. Maximum activity was obtained at 48 h incubation except for D-xylose that was at 24 h. High concentrations (200 mM) of L-arabitol also caused repression of the arabinofuranosidase. A unique band of activity showing the same migration pattern as the purified AbfB was found in zymograms of cell free extracts, indicating that the activity was likely due to this sole enzyme. The assessment of the influence of inducers and repressors on the activity of AbfB and on the expression of the abfB gene by real time PCR indicated that regulation was transcriptional. DNA amplifications using a pair of degenerated primers flanking an internal fragment within α-L-arabinofuranosidase genes of the family 51 of glycoside hydrolases evidenced that these enzymes are widespread in Bifidobacterium. The aminoacidic sequences of bifidobacteria included a fragment of four to six residues in the position 136-141 that was absent in other microorganisms ; This work was financed by European Union FEDER funds and the Spanish Plan Nacional de I + D (project AGL2004-06088-C02-01/ALI). L. Noriega was the recipient of a predoctoral fellowship from Fundación para la investigación Científica y Técnica (FICYT, Asturias, Spain). M. Gueimonde was funded by a Juan de la Cierva postdoctoral contract from the Spanish Ministry of Education and Science. ; Peer reviewed

Our aim was to determine the effects of probiotic supplementation (Bifidobacterium longum 35624; 1 billion CFU·d−1) on exercise performance, immune modulation, and cognitive outlook in collegiate female athletes during six weeks of offseason training. Seventeen National Collegiate Athletic Association (NCAA) Division 1 collegiate female swimmers participated in this two-group matched, double-blind, placebo controlled design. Via stratified randomization, participants were assigned to probiotic (B. longum 35624; n = 8) or placebo (n = 9) groups. Pre, mid, and post-training, all participants completed exercise performance testing (aerobic/anaerobic swim time trials and force plate vertical jump) as well as provided serum (cytokine and gastrointestinal inflammatory markers) and salivary immunoglobulin A samples. Recovery-stress questionnaire for athletes (RESTQ-Sport) was administered at baseline and conclusion of each week. Data were analyzed by analysis of covariance (ANCOVA) by time point with the respective baseline values of each dependent variable being the covariate. No significant differences in exercise performance and biochemical markers were observed between groups following offseason training. Recovery-Stress Questionnaire for Athletes (RESTQ-sport) values in B. longum 35624 group had significantly higher (i.e., more desired; p < 0.05) values in sport recovery (weeks five and six) than placebo. Probiotic supplementation in collegiate female swimmers did not affect exercise performance or immune function throughout offseason training, but did indicate alterations in cognitive outlook.

Bifidobacterium longum subsp. infantis ATCC 15697 possesses five α-L-fucosidases, which have been previously characterized toward fucosylated human milk oligosaccharides containing α1,2/3/4-linked fucose [Sela et al.: Appl. Environ. Microbiol., 78, 795-803 (2012)]. In this study, two glycoside hydrolase family 29 α-L-fucosidases out of five (Blon_0426 and Blon_0248) were found to be 1,6-α-L-fucosidases acting on core α1,6-fucose on the N-glycan of glycoproteins. These enzymes readily hydrolyzed p-nitrophenyl-α-L-fucoside and Fucα1-6GlcNAc, but hardly hydrolyzed Fucα1-6(GlcNAcβ1-4)GlcNAc, suggesting that they de-fucosylate Fucα1-6GlcNAcβ1-Asn-peptides/proteins generated by the action of endo-β- N-acetylglucosaminidase. We demonstrated that Blon_0426 can de-fucosylate Fucα1-6GlcNAc-IgG prepared from Rituximab using Endo-CoM from Cordyceps militaris. To generate homogenous non-fucosylated N-glycan-containing IgG with high antibody-dependent cellular cytotoxicity (ADCC) activity, the resulting GlcNAc-IgG has a potential to be a good acceptor substrate for the glycosynthase mutant of Endo-M from Mucor hiemalis. Collectively, our results strongly suggest that Blon_0426 and Blon_0248 are useful for glycoprotein glycan remodeling.

Exopolysaccharides (EPS) isolated from two Bifidobacterium strains, one of human intestinal origin (Bifidobacterium longum subsp. longum IPLA E44) and the other from dairy origin (Bifidobacterium animalis subsp. lactis IPLA R1), were subjected to in vitro chemically simulated gastrointestinal digestion, which showed the absence of degradation of both polymers in these conditions. Polymers were then used as carbon sources in pH-controlled faecal batch cultures and compared with the non-prebiotic carbohydrate glucose and the prebiotic inulin to determine changes in the composition of faecal bacteria. A set of eight fluorescent in situ hybridisation oligonucleotide probes targeting 16S rRNA sequences was used to quantify specific groups of microorganisms. Growth of the opportunistic pathogen Clostridium histolyticum occurred with all carbohydrates tested similarly to that found in negative control cultures without added carbohydrate and was mainly attributed to the culture conditions used rather than enhancement of growth by these substrates. Polymers E44 and R1 stimulated growth of Lactobacillus/Enterococcus, Bifidobacterium, and Bacteroides/Prevotella in a similar way to that seen with inulin. The EPS R1 also promoted growth of the Atopobium cluster during the first 24 h of fermentation. An increase in acetic and lactic acids was found during early stages of fermentation (first 10-24 h) correlating with increases of Lactobacillus, Bifidobacterium, and Atopobium. Propionic acid concentrations increased in old cultures, which was coincident with the enrichment of Clostridium cluster IX in cultures with EPS R1 and with the increases in Bacteroides in cultures with both microbial EPS (R1 and E44) and inulin. The lowest acetic to propionic acid ratio was obtained for EPS E44. None of the carbohydrates tested supported the growth of microorganisms from Clostridium clusters XIVa+b and IV, results that correlate with the poor butyrate production in the presence of EPS. Thus, EPS synthesized by bifidobacteria from dairy and intestinal origins can modulate the intestinal microbiota in vitro, promoting changes in some numerically and metabolically relevant microbial populations and shifts in the production of short chain fatty acids. © 2009 Elsevier B.V. All rights reserved. ; This work was financially supported by the European Union FEDER funds and by the Plan Nacional de I + D under project AGL2007-62736. N. Salazar was the recipient of a predoctoral fellowship from the Spanish Ministry of Science and Innovation (FPI Program). ; Peer Reviewed