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In this study, the chemical structure and bioactive properties of the EPS of Pediococcus acidilactici MT41-11 isolated from camel milk were investigated. Two polysaccharide fractions (EPS-1, EPS-2) with molecular weights about 69.0 kDa were obtained, which were purified using DEAE-Sepharose and Sephadex G-100 chromatography. Based on monosaccharide composition, FT-IR, and 1D, 2D NMR spectra, concluded that EPS-1 had a backbone composed of →2)-α-d-Manp-(1→, →3)-α-d-Manp-(1→ and with branches containing α-d-Manp-(1→, EPS-2 had a backbone composed of →6)-β-d-Glcp-(1→, and with branches containing →2)-α-l-Fucp-(1→, →3)-α-d-Glcp-(1→, →2)-α-d-Glcp-(1→, β-d-Glcp-(1→, and α-d-Glcp-(1→. Remarkably, in vitro assays showed that EPS possessed multiple bioactive properties, including stimulating Lactobacillus growth and a high DPPH free radical scavenging activity. Also, it has a good ability to anti-biofilms. Overall, the analysis of all data showed EPS from P. acidilactici MT41–11 can be used as anti-oxidant, anti-biofilm agent, and also as a potential candidate prebiotic for health food or medicine industry.

exopolysaccharides, Prebiotics, anti-biofilm activity, anti-oxidant activity, Pediococcus acidilactici

Publication DOI: 10.1016/j.ijbiomac.2021.06.152
Journal NLM ID: 7909578
Publisher: Butterworth-Heinemann
Correspondence: Yongqing Ni
Institutions: The Food Science and Technology College, Shihezi University, Shihezi, Xinjiang 832000, PR China
Methods: 13C NMR, 1H NMR, NMR-2D, composition analysis, HPLC, GPC, SEC, radical scavenging assay, SEM, FT-IR, anti-biofilm activity assay

One of the major problems encountered during quantitative studies of phagocytosis is the discrimination without ambiguity between intracellular and extracellular particles. This difficulty is especially acute when zymosan particles are used because of their poor affinity for dyes. We show in this paper that zymosan particles may be stained by a mixture of a basic dye and tannic acid in water (or in an isotonic non saline solution). Crystal violet is one of the most suitable dyes and by combining this staining step with May-Grünwald Giemsa staining, it was possible to observe two populations of macrophage-associated particles. One comprises blue violet particles (BVP), and the second consists of particles with a purple-stained core (PPC). Treating macrophages in culture with various concentrations of cytochalasin B decreases the number of PPC and increases the number of BVP, in a dose dependant manner. Moreover, treatment with α-mannan or laminarin decreases the number of cell-associated particles, especially that of PPC. From these observations we concludes that BVP are extracellularly located and PPC are ingested.

NCBI PubMed ID: 8083517
Journal NLM ID: 1305440
Institutions: Université Louis Pasteur, Département d'Immunologie, Immunopharmacologie et Pathologie, Illkirch, France
Methods: ELISA, enzymatic digestion, HPAEC-PAD, acetolysis

Previous results suggested that the chitin ring present at the yeast mother-bud neck, which is linked specifically to the nonreducing ends of β(1-3)glucan, may help to suppress cell wall growth at the neck by competing with β(1-6)glucan and thereby with mannoproteins for their attachment to the same sites. Here we explored whether the linkage of chitin to β(1-3)glucan may also prevent the remodeling of this polysaccharide that would be necessary for cell wall growth. By a novel mild procedure, β(1-3)glucan was isolated from cell walls, solubilized by carboxymethylation, and fractionated by size exclusion chromatography, giving rise to a very high-molecular-weight peak and to highly polydisperse material. The latter material, soluble in alkali, may correspond to glucan being remodeled, whereas the large-size fraction would be the final cross-linked structural product. In fact, the β(1-3)glucan of buds, where growth occurs, is solubilized by alkali. A gas1 mutant with an expected defect in glucan elongation showed a large increase in the polydisperse fraction. By a procedure involving sodium hydroxide treatment, carboxymethylation, fractionation by affinity chromatography on wheat germ agglutinin-agarose, and fractionation by size chromatography on Sephacryl columns, it was shown that the β(1-3)glucan attached to chitin consists mostly of high-molecular-weight material. Therefore, it appears that linkage to chitin results in a polysaccharide that cannot be further remodeled and does not contribute to growth at the neck. In the course of these experiments, the new finding was made that part of the chitin forms a noncovalent complex with β(1-3)glucan.

protein, glucan, solvent, glycosidase, Saccharomyces cerevisiae, chitin, glucan endo 1, 3 beta glucosidase, sodium hydroxide

NCBI PubMed ID: 22366124
Publication DOI: 10.1128/EC.05328-11
Journal NLM ID: 101130731
Publisher: American Society for Microbiology
Correspondence: enricoc@bdg10.niddk.nih.gov
Institutions: Laboratory of Biochemistry and Genetics, NIDDK, National Institutes of Health, Department of Health and Human Services, Bethesda, USA, Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain, Laboratory of Biochemistry and Genetics, NIDDK, National Institutes of Health, Department of Health and Human Services, Bethesda, United States
Methods: methylation, alkaline hydrolysis, CC

Fungal β-glucans have received a lot of interest due to their proinflammatory activity towards cells of the innate immune system. Although commonly described as (1➔3)-β-glucans with varying degree of (1➔6)-branching, the fungal β-glucans constitute a diverse polysaccharide class. In this study, the alkali-soluble β-glucans from the edible mushroom Pleurotus eryngii were extracted and characterized by GC, GC-MS and 2D NMR analyses. The extracts contain several structurally different polysaccharides, including a (1➔3)-β-d-glucan with single glucose units attached at O-6, and a (1➔6)-β-d-glucan, possibly branched at O-3. The immunomodulatory activities of the P. eryngii extracts were assessed by investigating their ability to bind to the receptor dectin-1, and their ability to induce production of the proinflammatory cytokines TNF-α, IL-6 and IL-1β in LPS-differentiated THP-1 cells. Although the samples were able to bind to the dectin-1a receptor, they did not induce production of significant levels of cytokines in the THP-1 cells. Positive controls of yeast-derived (1➔3)-β-d-glucans with branches at O-6 induced cytokine production in the cells. Thus, it appears that the P. eryngii β-glucans are unable to induce production of proinflammatory cytokines in LPS-differentiated THP-1 cells, despite being able to activate the human dectin-1a receptor.

NMR, THP-1, Dectin-1, dispersion, mushroom glucans

NCBI PubMed ID: 37839837
Publication DOI: 10.1016/j.carbpol.2023.121367
Journal NLM ID: 8307156
Publisher: Elsevier
Correspondence: C.F. Ellefsen
Institutions: Department of Pharmacy, University of Oslo, Sem S?lands vei 3, 1068 Blindern, NO-0371 Oslo, Norway, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem S?lands vei 6/8, NO-7491 Trondheim, Norway
Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, sugar analysis, GC, cytokine analysis, extraction, statistical analysis, elemental analysis, cell viability assay, DEPT, DLS, bioassays, dispersion method