Type II arabinogalactan (AG-II) is a suitable carbohydrate source for Bifidobacterium longum subsp. longum, but the degradative enzymes have never been characterized. In this study, we characterized an exo-β-1,3-galactanase, BLLJ_1840, belonging to glycoside hydrolase family 43 from B. longum subsp. longum JCM1217. The recombinant BLLJ_1840 expressed in Escherichia coli hydrolyzed β-1,3-linked galactooligosaccharides but not β-1,4- and β-1,6-linked galactooligosaccharides. The enzyme also hydrolyzed larch wood arabinogalactan (LWAG), which comprises a β-1,3-linked galactan backbone with β-1,6-linked galactan side chains. The kcat/Km ratio of dearabinosylated LWAG was 24-fold higher than that of β-1,3-galactan. BLLJ_1840 is a novel type of exo-β-1,3-galactanase with a higher affinity for the β-1,6-substituted β-1,3-galactan than for nonsubstituted β-1,3-galactan. BLLJ_1840 has 27% to 28% identities with other characterized exo--1,3-galactanases from bacteria and fungi. The homologous genes are conserved in several strains of B. longum subsp. longum and B. longum subsp. infantis but not in other bifidobacteria. Transcriptional analysis revealed that BLLJ_1840 is intensively induced with BLLJ_1841, an endo-β-1,6-galactanase candidate, in the presence of LWAG. This is the first report of exo-β-1,3-galactanase in bifidobacteria, which is an enzyme used for the acquisition of AG-II in B. longum subsp. longum.
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http://dx.doi.org/10.1128/AEM.00802-14 | DOI Listing |
J Food Drug Anal
December 2024
Division of Research and Analysis, Food and Drug Administration, Ministry of Health and Welfare, Taipei, Taiwan, R.O.C.
Limosilactobacillus reuteri is a probiotic bacterium known for its numerous beneficial effects on human health and is commonly utilized in various dietary supplements. Previously, we encountered difficulties in isolating L. reuteri from retail dietary supplements containing complex probiotic compositions by using non-selective media such as de Man, Rogosa, and Sharpe (MRS) agar.
View Article and Find Full Text PDFAllergy Asthma Proc
January 2025
From the Department of Microbiology-Immunology, Georgetown University Medical Center, Washington, D.C.
Allergen immunotherapy (AIT) is currently the most effective immunologic form of treatment for patients with atopic allergic diseases commonly used by allergist/immunologists to reduce allergic symptoms by gradually desensitizing the immune system to specific allergens. Currently, the primary mechanism of AIT emphasizes the crucial role of immune regulation, which involves a shift from a T-helper type 2 (Th2) cell response, which promotes allergy, to a T-regulatory (Treg) cell population, which inhibits the allergic inflammatory response through the production of immunosuppressive cytokines interleukin 10 and transforming growth factor β, which play pivotal roles in suppressing the allergic reaction. In a series of previous in vitro and in vivo experiments, we have demonstrated the capacity of synthetic methylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotide (ODN) moieties as well as methylated genomic DNA ODN motifs from Bifidobacterium longum subspecies infantis to activate Treg cell differentiation in contrast to the unmethylated ODN moiety, which promotes proinflammatory responses driven by Th17-mediated responses.
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December 2024
School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen 510006, China. Electronic address:
Ulcerative colitis (UC) is an inflammatory bowel disease marked by gut inflammation and microbial dysbiosis. Exopolysaccharides (EPS) from probiotic bacteria have been shown to regulate microbial composition and metabolism, but their role in promoting probiotic growth and alleviating inflammation in UC remains unclear. Here, we investigate BLEPS-1, a novel EPS derived from Bifidobacterium longum subsp.
View Article and Find Full Text PDFNutrients
November 2024
Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy.
Cells
December 2024
Cell Biology Area, Molecular Biology Department, Campus de Vegazana s/n, Universidad de León, 24071 León, Spain.
With increasing evidence showing the connections between the microbiome, neurophysiology, and behavior, our research endeavors to investigate whether the consumption of a combination of two postbiotics with antioxidant effects can affect behavior regulation in model species. Here, we worked with a combination (1:1 ratio) of heat-treated subsp. ES1 (CECT7347) and BPL15 (CECT8361) as a dietary supplement.
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