1,721,062 research outputs found
On the specificity of a bacteriophage-borne endoglycanase for the native capsular polysaccharide produced by Klebsiella pneumoniae SK1 and its derived polymers
No full textBacterial Capsular Polysaccharides and Exopolysaccharides
No full textBacteria often produce an external layer of polysaccharides, characterized by a definite primary structure, which in turn is responsible for sometimes remarkable physicochemical properties. Although the number of monosaccharides which constitute the polymers is rather low, the great number of different polysaccharides defined up to now shows the capacity of the microbes to exploit the possible isomers and linkage types of the building blocks. Furthermore, variability is often introduced by the presence of non-carbohydrate groups linked to
hydroxyl, carboxyl or amine functions. In this chapter, examples of polysaccharides produced by Gram-negative and Gram-positive pathogenic bacteria are given, together with a description of those polymers that are interesting for industrial and biotechnological purposes. Some discussion is also devoted to the general features of shapes that polysaccharides may adopt in solution. The biological functions of
these biomolecules are discussed particularly in relation to their role in human infection processes. The structures of the polysaccharides produced by species of the Burkholderia cepacia complex is reported as an example of a current investigation devoted to the understanding of the role of these biopolymers in lung infections
Periodate oxidation of cyclosophoraoses: a quantitative analysis of the reaction products by ionspray mass spectrometry
No full textHost-guest complex formation in cyclotrikis-(1-6)-[alfa-D-glucopyranosil-(1-4)-beta-D-glucopyranosil].
No full textDetermination of the size and degree of acetyl substitution of oligosaccharides from Neisseria meningitidis group A by ionspray mass spectrometry
No full textStructural determination of the polysaccharide isolated from biofilms produced by a clinical strain of Klebsiella pneumoniae
Full text linkKlebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy-seven different K antigens have been described and they are the basis for K serotyping.
Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid
medium, where it formed floating biofilms (flocs). Extraction and purification of the polysaccharide fraction showed that only one main carbohydrate polymer was present in both adherent biofilms and flocs.
Composition and linkage analysis, Smith degradation followed by ESI-MS, 1D and 2D NMR spectroscopy revealed that the polysaccharide belong to the type K24 and has the following structure: [2)[beta-D-Manp(1-4)]-alfa-D-GlcpA-(1-3)-alfa-D-Manp-(1-2)-alfa-D-Manp-(1-3)-beta-D-Glcp-(1 ]
Study of the inclusion complexes of aromatic molecules with cyclodextrins using ionspray mass spectrometry
No full textExopolysaccharides of the plant pathogens Pseudomonas corrugata and Ps. flavescens and the saprophyte Ps. chlororaphis
No full textEffect of methylation of beta-cyclodextrin on the formation of inclusion complexes with aromatic compounds. An ionspray mass spectrometry investigation
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