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PubMed1989

Gardnerella vaginalis has a gram-positive cell-wall ultrastructure and lacks classical cell-wall lipopolysaccharide.

Gardnerella vaginalis has a very thin cell wall with a characteristic gram-negative staining pattern and an apparent lamellar structure when viewed at an oblique angle by electronmicroscopy. Examination at right angles to the cell-wall plane and by freeze-etching showed absence of an outer membrane or any other lamellar structure. Cell-wall extracts made by methods specific for lipopolysaccharide (LPS) gave negative reactions by silver staining and for endotoxin in the limulus amoebocyte lysate assay. 2-Keto-3-deoxy-D-manno-2-octonoic acid (KDO), heptose and hydroxy fatty acids specific for LPS were not detected in the extracts. G. vaginalis cell walls are unequivocally gram-positive in their ultrastructural characteristics and chemical composition.

Cell Wall↗

PubMed1995

A gene region in Dichelobacter nodosus encoding a lipopolysaccharide epitope.

Dichelobacter nodosus is a Gram-negative anaerobic bacterium that is the causative organism of footrot in sheep. A D. nodosus locus responsible for a modification of the host lipopolysaccharide (LPS) in Escherichia coli was cloned and sequenced. Genetic studies showed that the modification occurred within the inner-core region of the host LPS, most likely to one or more of the heptose molecules. Antibodies eluted from the modified LPS reacted preferentially with the lipid-A-core region of D. nodosus LPS, suggesting that the cloned epitope was present in this region of the D. nodosus LPS. The gene responsible for the modification, IpsA, potentially encoded a polypeptide of approximately 37 kDa which was highly basic, a characteristic of enzymes which interact with the acidic inner LPS core. The IpsA gene appeared to be arranged in a complex operon with a downstream gene, prfC, which encoded a protein with similarity to E. coli peptide-chain release factor 3.

Amino Acid Sequence↗

PubMed1996

An immunochemical study of serological cross-reaction between lipopolysaccharides from Vibrio cholerae O22 and O139.

A comparative chemical and serological study of the LPS of Vibrio cholerae O139 and O22 was performed. Chemical analysis revealed that the sugar composition of the LPS of strain O22 was quite similar to that of O139 LPS. Each contained D-glucose, L-glycero-D-manno-heptose, colitose (3,6-dideoxy-L-galactose), D-fructose, D-glucosamine, D-quinovosamine and D-galacturonic acid. The O-antigenic relationship between the two strains was analysed by passive haemolysis (PH) and passive haemolysis inhibition (PHI) tests with the respective LPS being used as antigens to sensitize sheep red blood cells (SRBC) and, in the latter case, as inhibitors in a PH system that consisted of LPS-sensitized SRBC, guinea-pig complement and anti-O139 or anti-O22 antiserum, both unabsorbed and absorbed with the heterologous antigen. In the PH experiment, unabsorbed anti-O139 antiserum had haemolytic titres of 66,000 and 22,000 against O139 LPS- and O22 LPS-sensitized SRBC, respectively; unabsorbed anti-O22 antiserum had haemolytic titres of 900 and 13,000, respectively. Thus, the anti-O139 antiserum contained an antibody that reacted with a heterologous O22 antigen at a high titre (22,000) and this antibody was completely removed from anti-O139 antiserum with the O22 antigen. The anti-O22 antiserum contained an antibody that reacted with the heterologous O139 antigen at a low titre (900) and this antibody was completely removed from anti-O22 antiserum with the O139 antigen. In PHI tests O139 LPS and O22 LPS each strongly inhibited (the ID50 of LPS ranged from 0.03 to 0.14 microgram ml-1) the heterologous haemolytic systems of both O139 LPS-sensitized SRBC/anti-O22 antiserum and O22 LPS-sensitized SRBC/anti-O139 antiserm, which are substantially equivalent to the common antigen factor in the O139 LPS-sensitized SRBC/anti-O22 antiserum system and the common antigen factor in the O22 LPS-sensitized SRBC/anti-O139 antiserum system, respectively. The results indicated that the O antigen of O139 is closely related to that of O22 in an a,b-a,c type of relationship where a is common antigenic factor, b is an O139-specific antigenic factor and c is an O22-specific antigenic factor.

Antibodies, Bacterial↗

PubMed2005

The role of Dam methylation in phase variation of Haemophilus influenzae genes involved in defence against phage infection.

Haemophilus influenzae uses phase variation (PV) to modulate the activity of its defence systems against phage infection. The PV of the restriction-modification (R-M) system HindI, the main defence system against phage infection and incoming chromosomal and phage DNA in H. influenzae Rd, is driven by changes of the pentanucleotide repeat tract within the coding sequence of the hsdM gene and is influenced by lack of Dam methylation. Phase-variable resistance/sensitivity to phage infection correlates with changes in lipooligosaccharide (LOS) structure and occurs by slippage of tetranucleotide repeats within the gene lic2A, coding for a step in the biosynthesis of LOS. The lack of Dam activity destabilizes the tetranuclotide (5'-CAAT) repeat tract and increases the frequency of switching from sensitivity to resistance to phage infection more than in the opposite direction. The PV of the lgtC gene does not influence resistance or sensitivity to phage infection. Insertional inactivation of lic2A, but not lgtC or lgtF, leads to resistance to phage infection and to the same structure of the LOS as observed among phase-variable phage-resistant variants. This indicates that in the H. influenzae Rd LOS only the first two sugars (Glc-Gal) extending from the third heptose are part of bacterial phage receptors.

Bacterial Proteins↗

PubMed2006

Genetic and functional analyses of the lgtH gene, a member of the beta-1,4-galactosyltransferase gene family in the genus Neisseria.

Lipooligosaccharide (LOS) is a major virulence factor of the pathogenic Neisseria. Three galactosyltransferase genes, lgtB, lgtE and lgtH, responsible for the biosynthesis of LOS oligosaccharide chains, were analysed in five Neisseria species. The function of lgtH in Neisseria meningitidis 6,275 was determined by mutagenesis and chemical characterization of the parent and mutant LOS chains. The chemical characterization included SDS-PAGE, immunoblot, hexose and mass spectrometry analyses. Compared with the parent LOS, the mutant LOS lacked galactose, and its oligosaccharide decreased by three or four sugar units in matrix-assisted laser desorption ionization (MALDI)-MS analysis. The results show that lgtH encodes a beta-1,4-galactosyltransferase, and that the glucose moiety linked to heptose (Hep) in the alpha chain is the acceptor site in the biosynthesis of Neisseria LOS. To understand the sequence diversity and relationships of lgtB, lgtE and lgtH, the entire lgt-1 locus was further sequenced in three N. meningitidis strains and three commensal Neisseria strains, and compared with the previously reported lgt genes from Neisseria species. Comparison of the protein sequences of the three enzymes LgtB, LgtE and LgtH showed a conserved N-terminal region, and a highly variable C-terminal region, suggesting functional constraint for substrate and acceptor specificity, respectively. The analyses of allelic variation and evolution of 23 lgtB, 12 lgtE and 14 lgtH sequences revealed a distinct evolutionary history of these genes in Neisseria. For example, the splits graph of lgtE displayed a network evolution, indicating frequent DNA recombination, whereas splits graphs of lgtB and lgtH displayed star-tree-like evolution, indicating the accumulation of point mutations. The data presented here represent examples of the evolution and variation of prokaryotic glycosyltransferase gene families. These imply the existence of multiple enzyme isoforms for biosynthesis of a great diversity of oligosaccharides in nature.

Alleles↗

PubMed1979

Light-Dark Regulation of Starch Metabolism in Chloroplasts: I. Levels of Metabolites in Chloroplasts and Medium during Light-Dark Transition.

In Spinacia oleracea the kinetics of CO(2) fixation, of starch formation, and of changes in the levels of metabolites in chloroplasts and the surrounding medium has been investigated during light-dark and dark-light transitions with isolated intact chloroplasts.The internal level of orthophosphate stays constant throughout a light-dark-light cycle. The concentration of 3-phosphoglycerate in the chloroplasts is about 4 millimolar in the light and decreases in the dark within 3 minutes to about 1.6 millimolar. The level of the hexose monophosphates shows a reverse trend, increasing from about 2.2 millimolar in the light to 6 millimolar in darkness. In the subsequent light period both compounds reach their original levels within 2 minutes. The chloroplastic concentrations of dihydroxyacetone phosphate, of the pentose monophosphates, and of the hexose- and heptose bisphosphates remain constant at about 0.4 millimolar throughout the light-dark-light cycle.In the medium, the concentration of 3-phosphoglycerate increases and dihydroxyacetone phosphate decreases in the dark phase: this is due to an exchange of internal 3-phosphoglycerate for external dihydroxyacetone phosphate. Part of the reimported dihydroxyacetone phosphate is converted into hexose monophosphates via aldolase and fructose bisphosphatase during the first minutes of darkness. Due to the observed exchange transport reactions, the large difference between the transenvelope concentration gradients of 3-phosphoglycerate, dihydroxyacetone phosphate, and orthophosphate which exist in the light, is completely abolished after 2 to 3 minutes in the dark.The kinetics and the magnitudes of the changes of metabolite concentrations during the light-dark-light cycle are compared to the kinetics of starch formation, and their relevance for a possible light-dark regulation of starch synthesis is discussed.

Journal Article↗

PubMed1982

On the Participation of Phosphoribulokinase in the Light Regulation of CO(2) Fixation.

CO(2) fixation by a suspension of isolated spinach chloroplasts was terminated by turning off the light, and changes of metabolite levels in the chloroplast stroma and the surrounding medium were assayed. Whereas CO(2) fixation comes to a total stop within 15 seconds, a conversion of triose phosphates to heptose, hexose, and pentose monophosphates is found to occur for 1 to 2 minutes afterwards. It seems from these data that an inactivation of fructose and sedoheptulose bisphosphatases proceeds with a lag period. In contrast, the conversion of pentose monophosphates to ribulose 1,5-bisphosphate is inhibited immediately after the stop of illumination. As the stromal level of freely available ATP was not depleted under this condition, these data demonstrate that ribulose 5-phosphate kinase was very rapidly inactivated after darkening of the chloroplasts. Essentially, the same effect is also observed when CO(2) fixation is partially inhibited by addition of moderate concentrations of m-chlorocarbonyl phenylhydrazone, partially uncoupling photophosphorylation. It appears from these results, that the activity of ribulose 5-phosphate kinase is not only regulated by light through the mediation of reduced carriers like thioredoxin but also by alternative parameters, e.g. stromal metabolite levels.

Journal Article↗

PubMed1987

The Isolation and Partial Characterization of the Lipopolysaccharides from Several Rhizobium trifolii Mutants Affected in Root Hair Infection.

The lipopolysaccharides (LPSs) from Rhizobium trifolii ANU843 and several transposon (Tn5) symbiotic mutants derived from ANU843 were isolated and partially characterized. The mutant strains are unable to induce normal root hair curling (Hac- phenotype) or nodulation (Nod-phenotype) in clover plants. The LPSs from the parent and mutants are very similar in composition. Analysis by PAGE shows that the LPSs consist of higher and lower molecular weight forms. The higher molecular weight form of the LPSs exists in several aggregation states when PAGE is done in 0.1% SDS but collapses into a single band when PAGE is done in 0.5% SDS. Mild acid hydrolysis of all the LPSs releases two polysaccharides, PS1 and PS2. Immunoblots of the PAGE gels and enzyme linked immunosorbant assay inhibition assays show that the PS1 fractions contain the immunodominant sites of the LPSs and that these sites are present in the higher molecular weight form of the LPSs. All the PS1 fractions contain methylated sugars, 2-amino-2,6-dideoxyhexose, heptose, glucuronic acid, and 2-keto-3-deoxyoctonic acid (KDO). All the PS2 fractions contain galacturonic acid, mannose, galactose, and KDO. The PS2 fractions have a molecular weight of about 700. The KDO is present at the reducing end of both the PS1 and the PS2 fractions. The PS1 and PS2 fractions from the mutants contain more glucose than these fractions from the parent. The LPS from a deletion mutant contains less acyl groups than the other LPSs. Immunoblots of the LPSs show that the parent and nod A mutant LPSs contain an additional antigenic band which is not observed in the other LPSs.

Journal Article↗

PubMed1976

Biological activities of endotoxins from Yersinia enterocolitica.

The chemical properties and the general biological activities of lipopolysaccharide (LPS) and Boivin-type endotoxin obtained respectively by phenol-water and trichloroacetic acid extraction from Yersinia enterocolitica serotypes O3 and O9 were studied. The yield of LPS from the O9 strain was about 10% of the O3 strain possibly because of the lower solubility of O9-LPS in aqueous phase. However, the chemical composition of O9-LPS was similar to that of O3-LPS in the proportions of reducing sugar, glucosamine, heptose, KDO, and lipid A. In pyrogenicity and local Shwartzman reactivity in rabbits and lethality for mice, there was also no difference between O3 and O9-LPS. The anthrone-positive carbohydrate and lipid A contents of Boivin-type endotoxin from O3 were higher than those of the endotoxin from O9. The biological activities of Boivin-type endotoxin from O3 were also remarkably higher than those of the endotoxin from O9. It seems that endotoxin of Y. enterocolitica serotype O3 may play an important role in infection by this organism.

Adjuvants, Immunologic↗

PubMed1981

A comparative study of the sugar composition of O-antigenic lipopolysaccharides isolated from Vibrio alginolyticus and Vibrio parahaemolyticus.

A comparative study of the sugar composition of O-antigenic lipopolysaccharides (LPS) isolated from Vibrio alginolyticus and those from V. parahaemolyticus was carried out. 3-Deoxy-D-mannooctulosonic acid, 2-keto-3-deoxy octonate (KDO), a regular sugar constituent of gram-negative bacterial LPS, was totally absent from LPS of all V. alginolyticus strains examined as it was from those of V. parahaemolyticus. Furthermore, a KDO-like thiobarbituric acid test-positive substance, identical with that of either V. parahaemolyticus 07 or 012, was also found in LPS from three strains, 505-78, 905-78, and 1013-79 (designated tentatively as group I), out of the five strains of V. alginolyticus tested. LPS from the members of group I contained, as component sugars, glucose, galactose, L-glycero-D-manno-heptose, glucosamine, galactosamine, the KDO-like substance, and an unidentified amino sugar P1. Thus, LPS of the members of group I possessed a similar sugar composition which is similar to that of LPS from either V. parahaemolyticus 97 or 012. LPS of strain 1027-79, one of the other two strains (designated tentatively as group II), contained as component sugars, glucose, L-glycero-D-mannoheptose, glucosamine, galactosamine, galactosamine, and the other unidentified amino sugar P2, while LPS of strain 53-79, the other member of group II, contained galactose as an additional component. The results indicate that LPS of strain 1027-79 has a sugar composition similar to that of V. parahaemolyticus 09 LPS.

Amino Sugars↗

PubMed1984

Chemical and ultrastructural differences in endotoxic glycolipids from Salmonella minnesota Re mutant extracted with various solvent systems.

Endotoxic glycolipids ( ReGl ) extracted from the whole cells (WC) and cell walls of heptose-less Re mutant of Salmonella minnesota with hot phenol-water (PW), phenol-chloroform-petroleum ether (PCP), and chloroform-methanol (CM) were analyzed chemically and examined with an electron microscope. ReGl -PW-(WC) contained mannose and proteins as contaminants, ReGl -PCP(WC) consisted of an excess amount of amino compound (cadaverine), and ReGl -PCP(WC) consisted of proteins and cadaverine, in addition to the ReGl constituents. The ultrastructure of ReGl -PW(WC) resembled onions when stained with uranyl formate, and was spherical when stained with uranyl acetate, sodium phosphotungstate and ammonium molybdate, whereas those of ReGl -PCP(WC) and ReGl -CM(WC) were shaped like ribbons. However, the shadowed ultrastructures of ReGl -PCP(WC) and ReGl -CM(WC) showed small pieces of flat and wide sheets, respectively. ReGl -PCP(WC) re-extracted by the PW method was found to be converted into the onion-like structure which was similar to that of ReGl -PW(WC), while an intermediate form (fingerprint-like) was observed after re-extraction of ReGl -PW(WC) with PCP. It was strongly suggested that the ultrastructural arrangement of ReGl was dependent on the solvent systems used for extraction.

Alkanes↗

PubMed1984

Immunogenic dialyzable factor derived from a ribosomal fraction of Salmonella typhimurium III. Analysis of resistance induced by dialyzable factors.

Dialyzable factors (DF) were prepared from ribosomal fractions of several organisms including rough mutants of Salmonella typhimurium LT2, salmonella species of different serogroups, other enteric bacteria and gram-positive organisms, and tested for their immunogenicity against S. typhimurium infection in mice. All of them conferred local resistance on mice challenged intramuscularly with S. typhimurium LT2 in the early stage of immunization before the establishment of delayed-type hypersensitivity (DTH) to salmonella antigens. Although DFs of enteric bacteria including rough mutants of S. typhimurium induced DTH to salmonella antigens, only DF of a two-heptose mutant of S. typhimurium LT2 afforded significant mouse protection but others only prolonged the mean time to death. DF of Listeria monocytogenes induced the cross-reacting immunity which afforded the low level of mouse protection as well as an increase in mean time to death without inducing DTH. Passive transfer of anti-O antibody did not enhance the mouse protection provided by each DF. Resistance conferred by DF of S. typhimurium LT2 consisted of two phases: (i) nonspecific macrophage activation resulting in reduction of organisms at the infected site, which became active in the early stage of immunization and (ii) salmonella-specific immunity capable of preventing systemic infection, which became active in the late stage of immunization.

Animals↗

PubMed1993

Lipopolysaccharide isolated from a new O-antigenic form (O13) of Vibrio parahaemolyticus.

The chemical properties of a lipopolysaccharide (LPS) isolated from a new O-antigenic form (O13) of Vibrio parahaemolyticus were investigated. The LPS contained glucose, galactose, L-glycero-D-manno-heptose and glucosamine. 2-Keto-3-deoxy-octonate (KDO) was not detected in the LPS by the periodate-thiobarbituric acid test (Weissbach's reaction) under conventional hydrolysis conditions. Instead, phosphorylated KDO (X1 and X2) was found in its strong-acid hydrolysate. This sugar composition was identical to that of V. parahaemolyticus O3, O5 and O11 LPS, indicating that, based on the sugar composition, O13 LPS belongs to Chemotype III to which O3, O5 and O11 belong. In addition, structural study demonstrated the presence of KDO 4-phosphate in its inner-core region.

Carbohydrates↗

PubMed1993

A chemotaxonomic study of Vibrio fluvialis based on the sugar composition of the polysaccharide portion of the lipopolysaccharides.

A chemotaxonomic study was carried out with a new serotyping scheme comprising 35 O-antigen groups of Vibrio fluvialis on the basis of the sugar composition of the polysaccharide portion of their lipopolysaccharide (LPS). A previously developed rapid method of preparing samples for compositional sugar analysis was employed. The 35 O-antigen groups were divided into 21 chemotypes. It is noted that a rarely occurring component sugar of gram-negative bacterial LPS, D-glycero-D-manno-heptose, and two kinds of uronic acids, i.e., galacturonic acid of a weakly bound type and glucuronic acid of a strongly bound type, were found in common in all the 21 chemotypes. A characteristic sugar component of gram-negative bacterial LPS, 2-keto-3-deoxyoctonate (KDO), was not detectable in any of the 21 chemotypes. Instead, three kinds of "KDO-like substances" were found, one in each of three chemotypes (III, XI and XVII). They were strongly positive in Weissbach's periodate-thiobarbituric acid test for KDO, but definitely not identical to it in high-voltage paper electrophoresis (HVPE); the substance present in chemotype XI was indicated by HVPE to be 3-deoxy-D-threo-hexulosonic acid which is a sugar constituent of Vibrio parahaemolyticus O7 and O12 LPS.

Carbohydrates↗

PubMed1996

An N-[(R)-(-)-2-hydroxypropionyl]-alpha-L-perosamine homopolymer constitutes the O polysaccharide chain of the lipopolysaccharide from Vibrio cholerae O144 which has antigenic factor(s) in common with V. cholerae O76.

Chemical and serological studies were performed with the lipopolysaccharide (LPS) from Vibrio cholerae O144 (O144). The LPS of O144 contained D-glucose, D-galactose, L-glycero-D-manno-heptose, D-fructose, D-quinovosamine (2-amino-2,6-dideoxy-D-gluco-pyranose) and L-perosamine (4-amino-4,6-dideoxy-L-manno-pyranose). The perosamine, a major component sugar of the LPS from O144, was in an L-configuration, as is also the case in the LPS from V. cholerae O76 (O76), in contrast to the D-configuration of the perosamine in the LPS of V. cholerae O1. A structural analysis revealed that the O polysaccharide chain of the LPS from O144 is an alpha(1-->2)-linked homopolymer of (R)-(-)-2-hydroxypropionyl-L-perosamine. The serological cross-reactivity between O144 and O76 was clearly revealed by cross-agglutination and cross-agglutinin absorption tests with whole cells, as well as by passive hemolysis tests with sheep red-blood cells that had been sensitized with the LPS from O144 and O76. In contrast, in passive hemolysis tests, the LPS of O144 did not cross-react serologically with the LPSs from other strains such as V. cholerae O1 (Ogawa and Inaba), V. cholerae O140, Vibrio bio-serogroup 1875 (Original and Variant) and Yersinia enterocolitica O9. The LPSs from these strains consist of O polysaccharide chains composed of alpha(1-->2)-linked homopolymers of D-perosamine with various N-acyl groups, and they share the Inaba antigen factor C of V. cholerae O1 in common. The results obtained in this study demonstrate that the absolute configuration of the perosamine residue in homopolymers plays a very important role in the expression of the serological specificity of the Inaba antigen factor C of V. cholerae O1.

Agglutination Tests↗

PubMed1989

Chemical characterization and biologic properties of lipopolysaccharide from Bacteroides gingivalis strains W50, W83, and ATCC 33277.

The chemistry and selected biological activity of lipopolysaccharide (LPS) from Bacteroides gingivalis strains W50, W83, and ATCC 33277 were compared, as well as the role of this molecule as a mediator of selected inflammatory responses. Chemically, the LPSs consisted of 47-58% Lipid A, 5-10% carbohydrate, 0.05% 3-deoxy 2-octulosonic acid, 0.3% heptose, 3.8-5.2% hexosamine, and 2% phosphate. Rhamnose represented the dominant sugar (26-36%), with lesser amounts of glucose (18-34%), galactose (18-25%), mannose (9-12%), glucosamine (7-11%), and galactosamine (2-5%). The major fatty acids were: 13-methyl-tetradecanoate (42-45%), 3-OH-heptadecanoate (21-23%), hexadecanoate (16-19%), and 12-methyl-tetradecanoate (6-8%). SDS-PAGE and sodium deoxycholate-PAGE revealed the LPS to be a smooth chemotype. Differences in migration patterns between the virulent and avirulent strain LPSs also occurred. C3H/HeN macrophages (Mø) exposed to 1 microgram/ml of LPS released 3.2-4.2 ng of prostaglandin E (PGE)/ml of supernatant, representing 236-278% of control. Interleukin-1 (IL-1) activity in C3H/HeN and C3H/HeJ Mø exposed to 50 micrograms of LPS/ml was 382-724% and 270-300% of control, respectively; similar Mø exposed to 10 micrograms of LPS/ml released 1.6-2.0 ng and 0.3-0.5 ng of tumor necrosis factor (TNF)/ml of supernatant, respectively. Maximum TNF release in C3H/HeN Mø occurred in response to 50 micrograms of LPS/ml, and was sustained for up to 96 hours. These results suggest that LPS from the B. gingivalis strains stimulate cytokine production from Mø which, in turn, may play a role in orchestrating the inflammatory response for the development of periodontal diseases.

Bacterial Outer Membrane Proteins↗

PubMed1990

Isolation and characterization of lipopolysaccharide from Centipeda periodontii ATCC 35019.

Lipopolysaccharide (LPS) was extracted from cells of Centipeda periodontii ATCC 35019 by a hot phenol-water method, purified by nuclease treatment and by repeated ultracentrifugations. The LPS was composed of 21.7% hexose, 9.1% hexosamine, 10.3% fatty acid, 0.5% protein, 2.5% phosphorus, 4.3% 2-keto-3-deoxyoctonate(KDO) and 2.3% heptose. The major fatty acids of the LPS were 3OH C13:0 and C13:0. C. periodontii LPS was able to gelatinize Limulus amebocyte and to produce the local Schwartzman reaction in rabbits. LPS from C. periodontii exhibited strong immunobiological activities, mitogenicity on splenocytes of C3H/HeN mice, and stimulation of interleukin 1 (IL-1) production in peritoneal macrophages of C3H/HeN mice.

Endotoxins↗

PubMed1975

Studies of lipopolysaccharides from Pseudomonas aeruginosa.

Lipopolysaccharides from 13 strains of Pseudomonas aeruginosa representing seven serotypes of the Habs scheme have been analysed. The lipid A fractions, obtained by mild acid hydrolysis of the lipopolysaccharides, contained phosphorylated glucosamine residues substituted with dodecanoic, hexadecanoic, 2 hydroxydodecanoic, 3-hydroxydecanoic, and 3-hydroxydodecanoic acids (hexadecanoic acid and 2-hydroxdodecanoic acid were absent from one lipid A). Low-molecular-weight solutes released during the mild hydrolyses included 2-keto-3-deoxyoctonic acid, inorganic orthophosphates and pyrophosphates, ethanolamine mono, pyro and triphosphates. For most strains two polysaccharide fractions, one of which appeared to be the common core polysaccharide, were obtained. The major identifiable components and their approximate proportions in the core polysaccharides were glucose (3-4), rhamnose (1), galactosamine (1), alanine (1-1.5), phosphorus (4-6) and heptose (1-2). Rhamnose was absent from one polysaccharide another lacked both rhamnose and alanine but contained glucosamine. Small amounts of various amino sugars found in other core polysaccharides could be associated with the presence of higher-molecular-weight material. Such material was isolated from strain NCIB 8626. The high-molecular-weight polysaccharides obtained from ten strains were probably heterogeneous and consisted mainly of amino compounds, though rhamnose was a major component of four polysaccharades and arabinose was present in another. Fucosamine was the most common amino sugar, but quinovosamine, glucosamine, galactosamine, a possible aminohexuronic acid and unidentified amino compounds were also detected. The results of the survey are discussed in terms of the serological classification of the bacteria and of their sensitivity to EDTA.

Alanine↗