Structure, Physicochemical Properties and Biological Activity of Lipopolysaccharide from the Rhizospheric Bacterium Ochrobactrum quorumnocens T1Kr02, Containing d-Fucose Residues.

Lipopolysaccharides (LPSs) are major components of the outer membranes of Gram-negative bacteria. In this work, the structure of the O-polysaccharide of Ochrobactrum quorumnocens T1Kr02 was identified by nuclear magnetic resonance (NMR), and the physical-chemical properties and biological activity of LPS were also investigated. The NMR analysis showed that the O-polysaccharide has the following structure: →2)-ß-d-Fucf-(1→3)-ß-d-Fucp-(1→. The structure of the periplasmic glucan coextracted with LPS was established by NMR spectroscopy and chemical methods: →2)-ß-d-Glcp-(1→. Non-stoichiometric modifications were identified in both polysaccharides: 50% of d-fucofuranose residues at position 3 were O-acetylated, and 15% of d-Glcp residues at position 6 were linked with succinate. This is the first report of a polysaccharide containing both d-fucopyranose and d-fucofuranose residues. The fatty acid analysis of the LPS showed the prevalence of 3-hydroxytetradecanoic, hexadecenoic, octadecenoic, lactobacillic, and 27-hydroxyoctacosanoic acids. The dynamic light scattering demonstrated that LPS (in an aqueous solution) formed supramolecular particles with a size of 72.2 nm and a zeta-potential of -21.5 mV. The LPS solution (10 mkg/mL) promoted the growth of potato microplants under in vitro conditions. Thus, LPS of O. quorumnocens T1Kr02 can be recommended as a promoter for plants and as a source of biotechnological production of d-fucose.

The O-antigen structure of bacterium Comamonas aquatica CJG.

Genus Comamonas is a group of bacteria that are able to degrade a variety of environmental waste. Comamonas aquatica CJG (C. aquatica) in this genus is able to absorb low-density lipoprotein but not high-density lipoprotein of human serum. Using 1H and 13C NMR spectroscopy, we found that the O-polysaccharide (O-antigen) of this bacterium is comprised of a disaccharide repeat (O-unit) of d-glucose and 2-O-acetyl-l-rhamnose, which is shared by Serratia marcescens O6. The O-antigen gene cluster of C. aquatica, which is located between coaX and tnp4 genes, contains rhamnose synthesis genes, glycosyl and acetyl transferase genes, and ATP-binding cassette transporter genes, and therefore is consistent with the O-antigen structure determined here.

The chemical structure of the O-polysaccharide isolated from the lipopolysaccharide of Pectobacterium brasiliense IFB5527, a phytopathogenic bacterium of high economic importance.

Pectobacterium brasiliense is a widespread plant pathogenic bacterium classified to the Pectobacteriaceae family, which causes significant economic losses because of the developed soft rot and blackleg symptoms on potatoes and a wide spectrum of crops, vegetables, and ornamentals. One of the key virulence factors is a lipopolysaccharide due to its involvement in efficient colonisation of plant tissues and overcoming the host defence mechanisms. Thus, we structurally characterised the O-polysaccharide from the LPS of P. brasiliense strain IFB5527 (HAFL05) using chemical methods followed by GLC and GLC-MS as well as 1D and 2D NMR spectroscopy. The analyses revealed that the polysaccharide repeating unit consists of Fuc, Glc, GlcN and an unusual N-formylated 6-deoxy amino sugar, Qui3NFo, and has the structure shown below.

Structure elucidation and gene cluster of the O-antigen of Shewanella xiamenensis strain DCB-2-1 containing an amide of d-glucuronic acid with d-alanine and its bonding with U, Cr and V.

The aim of this work was to examine the structure and gene cluster of O-OPS of S. xiamenensis strain DCB-2-1 and survey its conceivability for chelating uranyl, chromate and vanadate ions from solution. O-polysaccharide (OPS, O-antigen) was isolated from the lipopolysaccharide of Shewanella xiamenensis DCB-2-1 and studied by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and sugar analysis. The following structure of the brunched pentasaccharide was established: where d-ß-GlcpA(d-Ala) is d-glucuronic acid acylated with NH group of d-Ala. The OPS structure established is unique among known bacterial polysaccharide structures. Interestingly, that dN-(d-glucuronoyl)-d-alanine derivative is not found in bacterial polysaccharides early. The O-antigen gene cluster of Shewanella xiamenensis strain DCB-2-1 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the OPS structure. Based on the analysis of the IR spectra of the isolated polysaccharide DCB-2-1 and the products of its interaction with UO2(NO3)2 ∗ 6H2O, NH4VO3 and K2Cr2O7, a method of binding them can be proposed. Laboratory experiments show that the use of polysaccharide can be effective in removing uranyl, chromate and vanadate from solution.

The O-specific polysaccharides structures of Pseudomonas strains isolated from the Ficus elastica.

Two Pseudomonas strains were isolated from the Ficus elastica leaves. The O-antigens were obtained using phenol-water method and mild acid degradation. The following structures of the O-polysaccharides were established by sugar analysis and 2D NMR spectroscopy: OPS of Pseudomonas psychrotolerans BIM B-1171 G -2)[aDGlcp(1-3)]bDRhap(1-3)aDManp(1-3)aDRhap(1- OPS of Pseudomonas sp. BIM B-1172 G -2)bDRhap(1-3)aDRhap(1-3)[aDGlcp(1-2)]aDRhap(1-.

O-specific polysaccharides structures of Pseudomonas strains isolated from the strawberry leaves.

Two Pseudomonas strains were isolated from the strawberry leaves. The O-antigens were obtained using phenol-water method and mild acid degradation. The following structures of the O-polysaccharides were established by sugar analysis and 2D NMR spectroscopy: OPS of Pseudomonas koreensis BIM B-970G →3)-α-D-FucNAcp-(1 â†’ 2)-ß-D-Quip3NAc-(1 â†’ 3)-α-L-6dTalp4OAc-(1→ OPS of Pseudomonas oryzihabitans BIM B-1072G →4)-α-L-FucpNAm3OAc-(1 â†’ 3)-α-D-QuipNAc-(1 â†’ 4)-ß-D-GlcpNAc3NAcA-(1→ Where Am - acetimidoyl.

Structure of O-Polysaccharide and Lipid A of Pantoea Agglomerans 8488.

The Pantoea agglomerans 8488 lipopolysaccharide (LPS) was isolated, purified and characterized by monosaccharide and fatty acid analysis. The O-polysaccharide and lipid A components of the LPS were separated by mild acid degradation. Lipid A was studied by electrospray ionization mass spectrometry (ESI-MS) and found to consist of hexa-, penta-, tetra- and tri-acylated species. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed the following structure of the O-polysaccharide repeating unit →3)-α-L-Rhap-(1→6)-α-D-Manp-(1→3)-α-L-Fucp-(1→3)-ß-D-GlcNAcp-(1→. The LPS showed a low level of toxicity, was not pyrogenic, and reduced the adhesiveness index of microorganisms to 2.12, which was twofold less than the control. LPS modified by complex compounds of germanium (IV) and tin (IV) were obtained. It was found that six LPS samples modified by Sn compounds and two LPS samples modified by Ge compounds lost their toxic activity when administered to mice in a dose of LD50 (105 µg/mice or 5 mg/kg). However, none of the modified LPS samples changed their serological activity in an Ouchterlony double immunodiffusion test in agar.

Structure, gene cluster of the O antigen and biological activity of the lipopolysaccharide from the rhizospheric bacterium Ochrobactrum cytisi IPA7.2.

Lipopolysaccharide (LPS) of Ochrobactrum cytisi IPA7.2, a bacterium isolated from the roots of Solanum tuberosum L., was extracted from dry bacterial cells and chemically characterized. The O-specific polysaccharide was obtained by mild acid hydrolysis of the LPS and studied by sugar analysis and 1H and 13C NMR spectroscopy, including 1H,1H COSY, 1H,1H TOCSY, 1H,1H ROESY, 1H,13C HSQC, and 1H,13C HMBC experiments. The polysaccharide was linear and consisted of trisaccharide repeating units of the following structure: A putative O-antigen gene cluster of O. cytisi IPA7.2 was identified and found to be consistent with the O-specific polysaccharide structure. The LPS of Ochrobactrum cytisi IPA7.2 promoted the growth of potato microplants in vitro.

Lipopolysaccharide of Pantoea agglomerans 7460: O-specific polysaccharide and lipid A structures and biological activity.

Lipopolysaccharide (LPS) was isolated from Pantoea agglomerans 7460 cells by phenol-water extraction. Mild acid degradation allowed to separate OPS and lipid A. Lipid A was analyzed by negative-ion mode ESI MS and found to consist mainly of hexaacylated derivative containing biphosphorylated GlcN disaccharide, four 14:0 (3-OH), 18:0 and 12:0 fatty acids. The structure of the O-specific polysaccharide was established by chemical, NMR and computational methods: The LPS of Р. agglomerans 7460 showed low level of toxicity and pyrogenicity to compare with LPS of E. coli O55:B5 and pyrogenal, respectively. The ability of the modified (succinylated) LPS, which have lost its toxicity, to block the toxic effects of native LPS has been shown.

Pantoea agglomerans P1a lipopolysaccharide: Structure of the O-specific polysaccharide and lipid A and biological activity.

O-specific polysaccharide and lipid A were obtained from the lipopolysaccharide from new strain of Рantoea agglomerans P1a by mild acid hydrolysis. It was found that the major form of lipid A presented by tetraacylated derivative containing biphosphorylated GlcN disaccharide, three 14:0 (3-OH) and 12:0 residues. The structure of the O-specific polysaccharide was established by chemical, NMR and computational methods: →3)-α-D-Manp-(1 → 4)-ß-D-Fucp-(1 → 4)-ɑ-D-Fucp-(1→The LPS of Р. agglomerans P1a showed low level of toxicity and pyrogenicity to compare with LPS of E. coli O55:B5 and pyrogenal (respectively).

Comparative Structural and Antigenic Characterization of Genetically Distinct Flavobacterium psychrophilum O-Polysaccharides.

Little is known about the underlying basis of serotype specificity among strains of Flavobacterium psychrophilum, the agent of rainbow trout fry syndrome and bacterial cold-water disease. The identification of different heat-stable O-serotypes among strains of this gram-negative pathogen does, however, suggest structural variations in the O-polysaccharide (O-PS) moiety of cell surface lipopolysaccharide (LPS). A trisaccharide composed of L-rhamnose (L-Rha), 2-acetamido-2-deoxy-L-fucose (L-FucNAc) and 2-acetamido-4-R-2,4-dideoxy-D-quinovose (D-Qui2NAc4NR), where R represents a dihydroxyhexanamido derivative, was previously identified as the repeating unit of Fp CSF259-93 O-PS. Interestingly, the O-PS gene cluster of this strain and that of Fp 950106-1/1, which belongs to a different O-serotype, are identical except for wzy, which encodes the putative polymerase that links trisaccharide repeats into O-PS chains. We have now found from results of glycosyl composition analysis and high-resolution nuclear magnetic resonance, that the linkage of D-Qui2NAc4NR to L-Rha, which is α1-2 for Fp CSF259-93 versus ß1-3 for Fp 950106-1/1, is the only structural difference between O-PS from these strains. The corresponding difference in O-serotype specificity was established from the reactions of rabbit and trout anti-F. psychrophilum antibody with purified O-PS and LPS. Moreover, LPS-based differences in antigenicity were noted between strains with O-PS loci identical to those of Fp CSF259-93 or Fp 950106-1/1, except for the genes predicted to direct synthesis of different R-groups in Qui2NAc4NR. The findings provide a framework for defining the genetic basis of O-PS structure and antigenicity and suggest that the repertoire of F. psychrophilum O-serotypes extends beyond what is presently recognized from serological studies of this important fish pathogen.

Structures of O-specific polysaccharides of Pseudomonas psyhrotolerans BIM B-1158G.

Strain of Pseudomonas psychrotolerans was cultured on the nutrient agar and in a liquid nutrient broth. Bacterial cells were phage-typed with bacteriophages specific to Pseudomonas. O-antigen was isolated from cells using phenol-water method and mild acid degradation. The following structures of the polysaccharides extracted were established by sugar analysis and 1D, 2D NMR spectroscopy: PSI→3)-α-D-Manp-(1→2)-α-D-Manp-(1→; PSII→3)-α-D-Rhap-(1→2)-ß-D-Rhap-(1→3)-α-D-Rhap-(1→; α-D-Glcp-(1Ë©; 2.

Structure and genetics of the O-specific polysaccharide of Escherichia coli O27.

The O-specific polysaccharide (O-antigen) is a part of the lipopolysaccharide on the cell surface of Gram-negative bacteria. The O-polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1H and 13C NMR spectroscopy. The following structure of the branched hexasaccharide repeating unit was established, which is unique among known structures of bacterial polysaccharides:where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure.

Lipopolysaccharide of Pantoea agglomerans 7969: Chemical identification, function and biological activity.

Lipopolysaccharide (LPS) of Pantoea agglomerans 7969 isolated from apple tree was purified and characterized chemically by sugar and fatty acid analysis. Lipid A was analysed by negative-ion mode ESI MS and found to consist mainly of hexa- and tetra-acyl species typical of E. coli lipid A. The O-specific polysaccharide of the LPS was studied by sugar analysis, Smith degradation, and one- and two-dimensional 1H and 13C NMR spectroscopy. The polysaccharide is built up of linear tetrasaccharide repeating units, and about ∼25% repeats contain glycerol 1-phosphate on the GlcNAc residue: →3)-α-l-Rha p-(1→6)-α-d-Man p-(1→3)-α-d-Fuc p-(1→3)-ß-d-Glc pNAc-(1→∼25% Gro-1-P-(O→6)⌋ The LPS showed low levels of toxic and pyrogenic activities and reduced the average adhesion and the index of adhesiveness.

Structure of the O-specific polysaccharides of Pseudomonas chlororaphis subsp. chlororaphis UCM B-106.

O-specific polysaccharide was obtained from the lipopolysaccharide of Pseudomonas chlororaphis subsp. chlororaphis UCM B-106 and studied by composition analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. The polysaccharide was found to contain a derivative of pseudaminic acid (Pse) and the following structure of the trisaccharide repeating unit was established: →4)-ß-Psep5Ac7Hb-(2 â†’ 6)-ß-d-Galf-(1 â†’ 3)-ß-d-Galp-(1→ where Pse5Ac7Hb indicates 5-acetamido-3,5,7,9-tetradeoxy-7-[(R)-3-hydroxybutanoylamino]-l-glycero-l-manno-non-2-ulosonic acid.

Structure elucidation and analysis of biosynthesis genes of the O-antigen of Escherichia coli O131 containing N-acetylneuraminic acid.

The O-polysaccharide (O-antigen) of Escherichia coli O131 was studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy. The following structure of the linear tetrasaccharide repeating unit of the polysaccharide was established: →8)-α-Neup5Ac-(2 â†’ 6)-ß-D-Galp-(1 â†’ 6)-ß-D-Galp-(1 â†’ 3)-ß-D-GalpNAc-(1→ The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the E. coli O131-antigen structure.

Structure and genetic basis of Yersinia similis serotype O:9 O-specific polysaccharide.

The O-polysaccharide (OPS, O-Ag) cap of LPS is a major virulence factor of Yersinia species and also serves as a receptor for the binding of lytic bacteriophage φR1-37. Currently, the OPS-based serotyping scheme for the Yersinia pseudotuberculosis complex includes 21 known O-serotypes that follow three distinct lineages: Y. pseudotuberculosis sensu stricto, Y. similis and the Korean group of strains. Elucidation of the Y. pseudotuberculosis complex OPS structures and characterization of the OPS genetics (altogether 18 O-serotypes studied thus far) allows a better understanding of the relationships among the various O serotypes and will facilitate the analysis of the evolutionary processes giving rise to new serotypes. Here we present the characterization of the OPS structure and gene cluster of Y. similis O:9. Bacteriophage φR1-37, which uses the Y. similis O:9 OPS as a receptor, also infects a number of Y. enterocolitica serotypes, including O:3, O:5,27, O:9 and O:50. The Y. similis O:9 OPS structure resembled none of the receptor structures of the Y. enterocolitica strains, suggesting that φR1-37 can recognize several surface receptors, thus promoting broad host specificity.

Structure of the O-specific polysaccharides from planktonic and biofilm cultures of Pseudomonas chlororaphis 449.

O-Specific polysaccharides were obtained from the lipopolysaccharides isolated from the planktonic and biofilm cultures of Pseudomonas chlororaphis 449 and studied by composition analysis and 1D and 2D (1)H and (13)C NMR spectroscopy. The following structure was established: -->4)-α-D-GalpNAc6Ac-(1-->3)-ß-D-QuipNAc-(1-->6)-α-D-GlcpNAc-(1-->ß-D-GlcpNAc-(1-->3) where the degree of non-stoichiometric 6-O-acetylation of GalNAc is ∼ 60% in the planktonic form or ∼ 10% in biofilm.