Structural studies of the O polysaccharides from the lipopolysaccharides of Azospirillum thiophilum BV-S and Azospirillum griseum L-25-5w-1.

Diazotrophic bacteria of the genus Azospirillum are known widely, because they are ubiquitous in the rhizosphere and can promote the growth and performance of nonlegume plants. Recently, more Azospirillum species have been isolated from sources other than plants or soil. We report the structures of the O polysaccharides (OPSs) from the lipopolysaccharides of the type strains A.

Structure of the O-polysaccharide from the moderately halophilic bacterium Halomonas fontilapidosi KR26.

Lipopolysaccharide was obtained from the aerobic moderately halophilic bacterium Halomonas fontilapidosi KR26. The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide and was examined by chemical methods and by H and C NMR spectroscopy, including H,H COSY, TOCSY, ROESY, and H,C HSQC, and HMBC experiments. The following structure of the linear tetrasaccharide repeating unit was deduced.

Use of cells in quercetin detection.

The possibility of detection and determination of flavonoids by using microbial cells was shown for the first time using the quercetin - Sp245 model system. The activity of the flavonoids quercetin, rutin and naringenin toward Sp245 was evaluated. It was found that when the quercetin concentration ranged from 50 to 100 μM, the number of bacterial cells decreased.

Structural characterization and physicochemical properties of the exopolysaccharide produced by the moderately halophilic bacterium Chromohalobacter salexigens, strain 3EQS1.

A strain, 3EQS1, was isolated from a salt sample taken from Lake Qarun (Fayoum Province, Egypt). On the basis of physiological, biochemical, and phylogenetic analyses, the strain was classified as Chromohalobacter salexigens. By 72 h of growth at 25 °C, strain 3EQS1 produced large amounts (15.

Structure and antiproliferative activity of the polysaccharide from Halomonas aquamarina related to Cobetia pacifica.

Here, the results of the structure and the activity of capsular polysaccharides isolated from the Halomonas aquamarina EG27S8QL and Cobetia pacifica KMM3878 have been described. Both polysaccharides were studied by spectroscopic and chemical methods and were found to be structurally related sulfated galactans differing in the position of the sulfate group: →6)-β-D-Galp3S-(1 → 4)-β-D-Galp3S-(1 → 6)-β-D-Galp3,4(S-Pyr)-(1 → [H. aquamarina EG27S8QL] →6)-β-D-Gal-(1 → 4)-β-D-Gal2,3S-(1 → 6)-β-D-Gal3,4(S-Pyr)-(1 → [C.

Structure of the 4-O-[1-Carboxyethyl]-d-Mannose-Containing O-Specific Polysaccharide of a Halophilic Bacterium sp. EG9S8QL.

The moderately halophilic strain sp. EG9S8QL was isolated among 11 halophilic strains from saline mud (Emisal Salt Company, Lake Qarun, Fayoum, Egypt). The lipopolysaccharide was extracted from dried cells of sp.

Structure of the O-specific polysaccharide from Azospirillum formosense CC-Nfb-7(T).

The lipopolysaccharide was obtained from the cells of Azospirillum formosense CC-Nfb-7(T), a diazotrophic bacterium isolated from agricultural soil. The O-specific polysaccharide (OPS) was released by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with H and C NMR spectroscopy, including H,H COSY, TOCSY, ROESY, H,C HSQC, and HMBC experiments, and Smith degradation. The following structure of partially methylated OPS composed of trisaccharide repeating units was established.

Bioremediation potential of a halophilic Halobacillus sp. strain, EG1HP4QL: exopolysaccharide production, crude oil degradation, and heavy metal tolerance.

A halophilic bacterial strain, EG1HP4QL, was isolated from a salt sample from Lake Qarun, Fayoum Province, Egypt. Morphological, physiological, biochemical, and phylogenetic analyses indicated that the strain belonged to the genus Halobacillus. Strain EG1HP4QL produced an extracellular polysaccharide (EPS), with production peaking (5.

Structure of the O-specific polysaccharide of Azospirillum doebereinerae type strain GSF71.

O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of plant-growth-promoting rhizobacteria Azospirillum doebereinerae GSF71 and studied by sugar analysis along with H and C NMR spectroscopy, including 2D H,H COSY, TOCSY, ROESY, H,C HSQC, and HMBC experiments. It was established that the polysaccharide is linear and consists of tetrasaccharide repeating units with the following structure.

Structure of the O-specific polysaccharide from a halophilic bacterium Halomonas ventosae RU5S2EL.

Halomonas ventosae RU5S2EL, a halophilic Gram-negative bacterium isolated from salt sediments of lake Elton (Russia), was cultivated and the lipopolysaccharide was extracted by the Westphal procedure. The O-specific polysaccharide (OPS) was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with H and C NMR spectroscopy, including H,H COSY, TOCSY, ROESY, H,C HSQC, and HMBC experiments as well as Smith degradation. The OPS was found to consist of branched pentasaccharide repeating units of the following structure.

Immunomodulatory activity of exopolysaccharide from the rhizobacterium Paenibacillus polymyxa CCM 1465.

Bacterial polysaccharides are promising stimulants of protective functions in humans and animals. We investigated the ability of exopolysaccharide from the rhizobacterium Paenibacillus polymyxa CCM 1465 to induce nonspecific resistance factors in the macroorganism. We examined in vitro the effect of the exopolysaccharide, produced with different carbon sources, on the phagocytic activity of murine macrophages, on the generation of reactive oxygen species and of enzymes (acid phosphatase and myeloperoxidase), on the proliferation of murine splenocytes, and on the synthesis of proinflammatory cytokines [interleukin-1 (IL-1) and tumor necrosis factor α (TNF-α)] by human mononuclear cells.

Structure of the O-specific polysaccharide from Azospirillum fermentarium CC-LY743.

O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of nitrogen-fixing bacterium Azospirillum fermentarium CC-LY743 (IBPPM 578) and was studied by sugar analysis along with H and C NMR spectroscopy, including H,H COSY, TOCSY, ROESY, and H,C HSQC and HMBC experiments. The polysaccharide was found to be linear and to consist of alterating α-l-fucose and α-d-mannose residues in tetrasaccharide repeating units of the following structure: →2)-α-D-Manp-(1 → 3)-α-L-Fucp-(1 → 3)-α-D-Manp-(1 → 3)-α-L-Fucp-(1→.

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4.

An O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide isolated by the phenol-water extraction from the halotolerant soil bacteria Azospirillum halopraeferens type strain Au4. The polysaccharide was studied by sugar and methylation analyses, selective cleavages by Smith degradation and solvolysis with trifluoroacetic acid, one- and two-dimensional (1)H and (13)C NMR spectroscopy. The following masked repeating structure of the O-specific polysaccharide was established: →3)-α-L-Rhap2Me-(1→3)-[β-D-Glcp-(1→4)]-α-D-Fucp-(1→2)-β-D-Xylp-(1→, where non-stoichiometric substituents, an O-methyl group (~45%) and a side-chain glucose residue (~65%), are shown in italics.

Nanoshell Assembly for Magnet-Responsive Oil-Degrading Bacteria.

The modified polyelectrolyte-magnetite nanocoating was applied to functionalize the cell walls of oil decomposing bacteria Alcanivorax borkumensis. Cationic coacervate of poly(allylamine) and 20 nm iron oxide nanoparticles allowed for a rapid single-step encapsulation process exploiting electrostatic interaction with bacteria surfaces. The bacteria were covered with rough 70-100-nm-thick shells of magnetite loosely bound to the surface through polycations.

Structure of the polysaccharides from the lipopolysaccharide of Azospirillum brasilense Jm125A2.

Two polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of associative nitrogen-fixing bacteria Azospirillum brasilense Jm125A2 isolated from the rhizosphere of a pearl millet. The following structures of the polysaccharides were established by sugar and methylation analyses, Smith degradation, and (1)H and (13)C NMR spectroscopy: [Formula: see text] Structure 1 has been reported earlier for a polysaccharide from A. brasilense S17 (Fedonenko YP, Konnova ON, Zdorovenko EL, Konnova SA, Zatonsky GV, Shaskov AS, Ignatov VV, Knirel YA.

Structural studies of the polysaccharides from the lipopolysaccharides of Azospirillum brasilense Sp246 and SpBr14.

Lipopolysaccharides from closely related Azospirillum brasilense strains, Sp246 and SpBr14, were obtained by phenol-water extraction. Mild acid hydrolysis of the lipopolysaccharides followed by GPC on Sephadex G-50 resulted in polysaccharide mixtures. On the basis of sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy data, it was concluded that both bacteria possess the same two distinct polysaccharides having structures 1 and 2: [structure: see text].

Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7.

Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (∼40%) 2-O-methylation of l-rhamnose.

Immunochemical characterization of the capsular polysaccharide of Azospirillum irakense KBC1.

The repeating unit structure of Azospirillum irakense KBC1 capsular polysaccharide (CPS) was established and was found to be identical to that of the O polysaccharide of A. irakense KBC1 lipopolysaccharide (LPS). The antigenic heterogeneity of the LPS and the CPS was shown to be related to differences in the macromolecular organization of these glycopolymers.

Structure of repeating units of a polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense SR80.

A high-molecular mass polysaccharide fraction was obtained by mild acid hydrolysis of the lipopolysaccharide of diazotrophic rhizobacterium Azospirillum brasilense SR80 followed by GPC on Sephadex G-50 Superfine. Studies by composition and methylation analyses, Smith degradation, and 1D and 2D (1)H and (13)C NMR spectroscopy demonstrated the presence of two structurally distinct repeating units having the following structures: It seems likely, although not proved, that these are repeats of two distinct polysaccharides rather than they build blocks within the same polysaccharide chain. The former structure is new, whereas the latter is closely related to the O-polysaccharide structure of A.

Biomimetic cell-mediated three-dimensional assembly of halloysite nanotubes.

Biomimetic architectural assembly of clay nanotube shells on yeast cells was demonstrated producing viable artificial hybrid inorganic-cellular structures (armoured cells). These modified cells were preserved for one generation resulting in the intact second generation of cells with delayed germination.

Structural analysis of the O-polysaccharide of the lipopolysaccharide from Azospirillum brasilense Jm6B2 containing 3-O-methyl-D-rhamnose (D-acofriose).

Two types of neutral O-polysaccharides were obtained by mild acid degradation of the lipopolysaccharide isolated by phenol-water extraction from the asymbiotic diazotrophic rhizobacterium Azospirillum brasilense Jm6B2. The following structure of the major O-polysaccharide was established by composition and methylation (ethylation) analyses, Smith degradation, and 1D and 2D (1)H and (13)C NMR spectroscopy: [structure: see text] where a non-stoichiometric (~60%) 3-O-methylation of D-rhamnose is indicated by italics.

Cyborg cells: functionalisation of living cells with polymers and nanomaterials.

Living cells interfaced with a range of polyelectrolyte coatings, magnetic and noble metal nanoparticles, hard mineral shells and other complex nanomaterials can perform functions often completely different from their original specialisation. Such "cyborg cells" are already finding a range of novel applications in areas like whole cell biosensors, bioelectronics, toxicity microscreening, tissue engineering, cell implant protection and bioanalytical chemistry. In this tutorial review, we describe the development of novel methods for functionalisation of cells with polymers and nanoparticles and comment on future advances in this technology in the light of other literature approaches.

An improved rapid method for the preparation of D-rhamnose.

A method is developed for the preparation of D-rhamnose from an O-polysaccharide (OPS) isolated by mild acid hydrolysis of Azospirillum brasilense SR75 cell mass. After the OPS hydrolysis, D-rhamnose was recovered by gel-permeation chromatography on Toyopearl TSK HW-40 and was crystallized. The sugar activity was demonstrated immunochemically.

Functional artificial free-standing yeast biofilms.

Here we report fabrication of artificial free-standing yeast biofilms built using sacrificial calcium carbonate-coated templates and layer-by-layer assembly of extracellular matrix-mimicking polyelectrolyte multilayers. The free-standing biofilms are freely floating multilayered films of oppositely charged polyelectrolytes and live cells incorporated in the polyelectrolyte layers. Such biofilms were initially formed on glass substrates of circular and ribbon-like shapes coated with thin layers of calcium carbonate microparticles.

Structural and functional peculiarities of the lipopolysaccharide of Azospirillum brasilense SR55, isolated from the roots of Triticum durum.

Azospirillum brasilense SR55, isolated from the rhizosphere of Triticum durum, was classified as serogroup II on the basis of serological tests. Such serogroup affiliation is uncharacteristic of wheat-associated Azospirillum species. The lipid A of A.