Lipopolysaccharides from Pseudomonas aeruginosa 01 (Lhnyi classification), 0 3 (Habs classification), 0 1 3 and 014 (Wokatsch classification), and strain NCTC 8505, which is also related to serogroup 0 3 (Habs), have structurally similar 0-specific polysaccharide chains built up of tetrasaccharide repeating units involving L-rhamnose (Rha), 2-acetamido-2-deoxy-~-glucose (GlcNAc), 2-acetamido-2-deoxy-~-galacturonic acid (GalNAcA), and a di-N-acyl derivative of bacillosamine (BacN): 2,4-diacetamido-2,4,6-trideoxy-~-glucose or 2-acetamido-2,4,6-trideoxy-4-[(S)-3-hydroxybutyramido]-~-glucose. The latter derivative was obtained free by solvolysis with hydrogen fluoride of carboxyl-reduced Habs 0 3 polysaccharide, and was identified by 'H-nuclear magnetic resonance spectroscopy and by mass spectrometry of the corresponding methylated alditol. Habs 03, Lhnyi 01, and Wokatsch 014 polysaccharides contained 0-acetyl groups.Solvolysis with hydrogen fluoride of the native Habs 0 3 polysaccharide resulted in selective cleavage of the glycosidic linkages of 6-deoxy sugars to give the trisaccharide fragment involving all three N-acylated amino sugars. Similar solvolysis of NCTC 8505 polysaccharide afforded a mixture of disaccharide and trisaccharide with N,N'-diacetylbacillosamine at the reducing end. Smith degradation of Habs 0 3 polysaccharide resulted in selective oxidation of rhamnose to give a glycoside of a trisaccharide with glyceraldehyde as the aglycone. Smith degradation of NCTC 8505 polysaccharide was complicated by the formation of the glycoside of a trisaccharide with an aglycone of unknown structure. A trisaccharide with rhamnose at the reducing end was also isolated after Smith degradation of the latter polysaccharide.Analysis of the composition and structure of all oligosaccharides obtained, and detailed examination of the ' jc-nuclear magnetic resonance spectra of these oligosaccharides, and of both intact and modified

Structural studies have been carried out on the 0-specific fraction from the lipopolysaccharide of Pseudomonas aeruginosa NCTC 8505, Habs serotype 03. The 0-specific polysaccharide has a tetrasaccharide repeating-unit containing residues of L-rhamnose (Rha), 2-acetamido-2-deoxy-~-glucose (GlcNAc), 2-acetamido-2-deoxy-~-galacturonic acid (GalNAcA), and 2,4-diacetamid0-2,4,6-trideoxy-i~-glucose (BacNAc,). The following structure has been assigned to the repeating-unit :The parent lipopolysaccharide is a mixture of S, R, and SR species, and its high phosphorus content is partly due to the presence of triphosphate residues, as found for other lipopolysaccharides from P. aeruginosa. In addition to phosphorus, heptose, a 3-deoxyoctulosonic acid, and amide-bound alanine, the core oligosaccharide contains glucose, rhamnose, and galactosamine (molar proportions 3 : 1 : 1). The rhamnose and part of the glucose are present as unsubstituted pyranoside residues: other glucose residues are 6-substituted. We have previously reported general analyses of the lipopolysaccharide from P. aeruginosa NCTC 8505 [19], belonging to Habs serogroup 03, and identified the amino sugars present in the 0-specific fraction [20,21]. Here we describe the results of further studies of these products, including evidence for the structure of the 0-specific polysaccharide. MATERIALS AND METHODS Isolation and Fractionation of LipopolysaccharideMethods used for the batch culture of Pseudomonas aeruginosa NCTC 8505, the preparation of cell walls, and the Abbreviations. BacNAc,, 2,4-diacetamido-2,4,6-trideoxygluccse (NN-diacetylbacillosamine); GalNAcA, 2-acetamido-2-deoxygakacturonic acid; GlcNAc, 2-acetamido-2-deoxyglucose; Rha, rhamnose.

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The enzymic digest of cell wall peptidoglycan from Clostridium saccharoperbutylacetonicum by phage HM 7 endolysin (N-acetylmuramyl-Lalanine amidase) was separated into two constituents on ion-exchange chromatography. One was a polysaccharide, which contained N-acetylglucosamine and N-acetylmuramic acid in the molar ratio of 1.00: 0.78. This polysaccharide was digested by phage HM 3 endolysin (N-acetylmuramidase), and the digested product was a saccharide composed of N-acetylglucosamine and N-acetylmuramic acid. The other was a peptide composed of glutamic acid, alanine, and diaminopimelic acid in the molar ratio of 1.00: 2.09: 1.05. Amino acid sequence of the isolated peptide was determined by Edman degradation method, and optical configuration of the component amino acids was confirmed by gas chromatography using their N-trifiuoroacetyl menthyl esters. These analyses indicated that the isolated peptide was composed of a tetrapeptide subunits of NH2-terminal-L-AIa-D-Glu-Dpm-D-Ala. A reasonable structure for the cell wall peptidoglycan was also proposed.Bacterial cell wall peptidoglycan is a major constituent of the cell wall and maintains the cell rigidity and shape. It is typically composed of an alternating polymer of i3-1,4-linked N-acetylglucosamine and N-acetylmuramic acid. Each muramic acid residue bears a short peptide chain consisting of D-glutamic acid, L-and D-alanine, and either meso-diaminopimelic acid or L-lysine. Little is known, however, about the study of cell wall peptidoglycan of genus Clostridium except for C. botulinum (1, 2) and C. welchii (3). In our previous paper (4), we presented hypothesis for the structure of the cell wall peptidoglycan from C. saccharoper-65