Structure of the extracellular gelling polysaccharide produced by Enterobacter (NCIB 11870) species

The gelling polysaccharide produced by a species of Enterobacter (NCIB 11870) contains L-fucose, D-glucose, and D-glucuronic acid in the ratios 1:2:1. Analysis of the methylated and methylated, carboxyl-reduced polysaccharide revealed terminal non-reducing glucose, (1----3)-linked fucose, (1----3,1----4)-linked glucose, and (1----4)-linked glucuronic acid in the ratios 1:1:1.2:0.8. From the results of Smith degradation of the polysaccharide and spectroscopic studies of the acidic tetra- and octa-saccharides produced by bacteriophage-induced enzymic depolymerization of the polysaccharide, the following tetrasaccharide repeating-unit is proposed. (Formula: see text). This repeating-unit is identical to that of the capsular polysaccharide produced by Klebsiella aerogenes serotype K54 except for the absence of O-acetyl groups. The effects of the O-acetyl groups on the secondary structure and rheological properties of these polysaccharides are discussed.     

Isolation, partial characterization, and biological properties of polysaccharides from crude papain

Two polysaccharides have been isolated from crude papain by precipitation of papain with ammonium sulfate, further precipitation of other proteins with trichloroacetic acid, and chromatography of the supernatant on DEAE-cellulose. The first polysaccharide to be eluted, designated PP-I, contained D-glucuronic acid, D-glucose, D-galactose, L-arabinose, and L-rhamnose, in the approximate molar ratios of 4:1:12:10:4. The other (PP-II), eluted at a higher salt-concentration, contained the same sugars (with about one-third less glucose and more uronic acid) in the approximate molar ratios of 13:1:40:26:12. Reduction of the uronic acid groups of PP-II produced a polysaccharide (PP-II-R) containing the same sugars in the approximate molar ratios of 2:11:37:28:12. Hydrolysis of a mixture of the two polysaccharides yielded an aldobiouronic acid, D-glucosyluronic acid-D-galactose. Neither polysaccharide preparation contained protein. These polysaccharides dramatically affected aggregation and alignment of normal human fibroblasts but had no effect on a mouse embryo fibroblast aneuploid cell-line that does not exhibit contact inhibition of growth or movement. In aggregating cells, these polysaccharides caused the cells to behave as contact-inhibited cells, that is, cell division and nuclear area were decreased.     

Exopolysaccharide Distribution of and Bioemulsifier Production by Acinetobacter calcoaceticus BD4 and BD413

The heavily encapsulated Acinetobacter calcoaceticus BD4 and the “miniencapsulated” single-step mutant A. calcoaceticus BD413 produced extracellular polysaccharides in addition to the capsular material. The molar ratio of rhamnose to glucose (3:1) in the extracellular BD413 polysaccharide fraction was similar to the composition of the capsular material. In both strains, the increase in capsular polysaccharide was parallel to cell growth and remained constant in stationary phase. The extracellular polysaccharides were detected starting from mid-logarithmic phase and continued to accumulate in the growth medium for 5 to 8 h after the onset of stationary phase. Strain BD413 produced one-fourth the total rhamnose exopolysaccharide per cell that strain BD4 did. Depending on the growth medium, 32 to 63% of the rhamnose polysaccharide produced by strain BD413 was extracellular, whereas in strain BD4 only 7 to 14% was extracellular. In all cases, strain BD413 produced more extracellular rhamnose polysaccharide than strain BD4 did. In glucose medium, strain BD413 also produced approximately 10 times more extracellular emulsifying activity than strain BD4 did. The isolated capsular polysaccharide obtained after shearing of BD4 cells showed no emulsifying activity. Thus, strain BD413 either produces a modified extracellular polysaccharide or excretes an additional substance(s) that is responsible for the emulsifying activity. Emulsions induced by the ammonium sulfate-precipitated BD413 extracellular emulsifier require the presence of magnesium ion and a mixture of an aliphatic and an aromatic hydrocarbon.     

Capsular polysaccharide expressed by Pasteurella piscicida grown in vitro

Abstract Pasteurella piscicida grown in a glucose-rich medium produces a capsule that can be see under light and electron microscopy. The capsular polysaccharide was purified and characterized by chemical and HPLC analysis. The polymer has the composition glucose/mannose/ N -acetylgalactosamine/galacturonic acid/acetic acid in the molar ratios of approximately 2.5:1.3:0.5:0.4:2.5. The polysaccharide was immunogenic in rabbits and did not cross-react with antibodies against the O-antigen lipopolysaccharide.     

Characterization of three capsular polysacharides produced by Burkholderia pseudomallei

Three kinds of capsular polysaccharide (CP) were found to be produced by Burkholderia pseudomallei. When the bacterium was grown with the medium without glycerol, CP-1a and CP-1b were produced. CP-1a was mainly 1.4-linked glucan and CP-1b was identified as a polymer composed of galactose and 3-deoxy-D-manno-octulosonic acid, whose chemical structure was recently reported by other laboratories. When the bacterium was grown with the medium containing 5" glycerol. CP-2 was synthesized. CP-2 contained galactose, rhamnose, mannose, glucose and a uronic acid in a ratio of approximately 3:1:0.3:1:1. Methylation analysis of the purified polysaccharides demonstrated that the two acidic polysaccharides. CP-1b and CP-2 shared no common structure, indicating that CP-2 was an acidic capsular polysaccharide whose chemical characters were not reported previously.     

灵芝胞外多糖的发酵条件及其组份的初步研究

本文报道了液体培养灵芝Gl8801菌林产生胞外多糖的最佳发酵条件和胞外多搪的化学组成。适宜的液体培养基(g/L):饴糖40,花生饼粉30,KH_2PO_41.5,(NH_4)_2SO_41.5,MgSO_4·7H_2O_(0.75),CaCO_32,最适起始pH5.5。300ml三角瓶装培养基60ml,发酵温度28℃。摇瓶(165rpm)培养7～8天,发酵液纯多糖含量可达880mg/L。灵芝胞外多糖分为水溶性多糖和水不溶性多糖两种。水溶性多糖的单糖组份为半乳糖、葡萄糖、阿拉伯糖和木糖,所含单糖重量比为6:4:4:1。不溶性多糖为葡聚糖。灵芝胞外多糖的糖环构型为吡喃糖,末端糖基构型,半乳糖为α型,葡萄糖为β型。     

Selective synthesis of polysaccharides by Rhizobium trifolii, strain TA-1

Abstract Rhizobium trifolii strain TA-1, produces one of each of the exocellular polysaccharides EPS, CPS and β-1,2-glucans as a major product during cultivation in glutamic acid-mannitol-salts (GMS) medium at 25°. In batch culture, the major exocellular polysaccharide product was acidic exopolysaccharide (EPS) under conditions of air saturation; capsular polysaccharide (CPS) under conditions of N-limitation and moderate oxygen supply; and cyclic β-1,2-glucans at high cell density and severe oxygen limitation.     

Structural determination and immunochemical characterization of the type V group B Streptococcus capsular polysaccharide

The type V capsular polysaccharide of group B Streptococcus has been isolated and purified, and its repeating unit structure determined. The native type V polysaccharide contains D-glucose, D-galactose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in a molar ratio of 3:2:1:1. Methylation analysis and 1H NMR and 13C NMR analysis of the native type V polysaccharide and of its specifically degraded products permitted the determination of the repeating unit structure of the type V polysaccharide: [formula: see text] The type V polysaccharide has certain structural features in common with other group B streptococcal capsular polysaccharides but is antigenically distinct: no immunologic cross-reactivity was observed between type V and types Ia, Ib, II, III, or IV polysaccharides. Studies of antibody binding to the partially degraded forms of the type V polysaccharide indicated that the native epitope is complex, involving most if not all of the sugar residues of the repeating unit.     

Structural aspects of the exudate from the fruit of Chorisia speciosa St. Hil

Mature fruit of Chorisia speciosa yield an exudate (E-I) following mechanical injury. The polysaccharide contains rhamnose, arabinose, xylose, mannose, glucose, galactose and glucuronic acid in molar ratios of 20:11:1:3:2:40:23. The main chain of the structure is composed by beta-galactopyranosyl units linked (1 --> 3) and (1 --> 6) as indicated by NMR spectra and methylation data. Arabinosef and rhamnose are terminal residues. In order to compare E-I with the polysaccharides from the fruit mesocarp, the latter was submitted to different extractions. The water fraction contains rhamnose, arabinose, xylose, mannose, glucose, galactose and uronic acid in molar ratios of 18:4:1:2:3:44:28. It was treated with CTAB yielding a precipitate which was decomplexed with NaCl, giving four fractions. The fraction obtained using 0.15 M NaCl had a quantitative composition similar that of E-I.     

Isolation of two different polysaccharides from halophilic Zoogloea sp.

Summary An extracellular polysaccharide producing bacterium Zoogloea sp. was isolated from marine environments. This strain could produce two different polysaccharides. One (water-soluble polysaccharide : WSP) was from cell-free liquid medium, the other (cell-bound polysaccharide : CBP) was obtained from cell surface. Both polysaccharides contained glucose, galactose and mannose as sugar components, but their molar ratios were different (WSP : 2:2:3, CBP : 1:2:2) and half of the sugar components existed as uronic acid form. Both polysaccharide productions started at the early stage of the logarithmic growth phase. The amount of WSP and CBP was influenced by culture conditions such as additional carbon and nitrogen sources. Isolated Zoogloea sp. showed a high product yield without the increase of cell mass.     

Isolation and characterization of exocellular polysaccharide produced byLactobacillus bulgaricus

Summary Lactobacillus bulgaricus strains grown on skim milk produce a viscosifying exocellular watersoluble heteropolysaccharide composed of galactose, glucose and rhamnose in an approximately molar ratio of 4:1:1. The molecular weight is approximately 500.000.     

Preliminary studies on the composition and rheological properties of the extracellular polysaccharide synthesized by Pseudomonas PBI (NCIB 11264).

A microorganism isolated from a carbohydrate-rich industrial effluent synthesized an exocellular slime polysaccharide composed of glucose and galactose in a molar ratio of 7.45 +/- 0.68 : 1, and two non-carbohydrate substituents acetate (3--4%) and pyruvate (5--9%). Contamination by rhamnose and mannose was detectable in crude polysaccharide samples. Solutions of the polysaccharide were pseudoplastic, but not thixotropic, and formed gels in the presence of certain trivalent cations.     

Structural studies on the capsular polysaccharide of Klebsiella serotype K40

The capsular polysaccharide of Klebsiella serotype K40 contained D-mannose, D-glucuronic acid, D-galactose, and L-rhamnose in the approximate molar ratios 1:1:1:2. The primary structure of the capsular polysaccharide has been investigated mainly by methylation analysis, periodate oxidation, characterization of oligosaccharides, base degradation reaction, and 1H and 13CNMR spectroscopy. The polysaccharide does not contain any pyruvic acetal or O-acetyl substitution. It has a pentasaccharide repeating unit of the following primary structure: alpha-D-Manp 1----4 ----4)-beta-D-GlcpA-(1----2)-alpha-L-Rhap-(1----3)-beta-D-Ga lp-(1----2)-alpha- L-Rhap-(1----.     

淫羊藿多糖的分离纯化及结构初步分析

从淫羊藿中提取多糖并鉴定其初步结构和单糖组成.采用超声-水提醇沉法提取粗多糖、Sevag法去蛋白、DEAE-52纤维素及Sephadex G-100柱层析法纯化得到淫羊藿多糖EPSⅠ-1和EPSⅡ-1.应用紫外光谱法和红外光谱法对其结构做初步分析.采用高效液相色谱法(HPLC)测定其单糖组成及摩尔比.均一的EPSⅠ-1和EPSⅡ-1多糖在紫外和红外中具有多糖的特征吸收峰,组成中含有吡喃环结构;EPSⅠ-1的单糖组成为鼠李糖和葡萄糖,摩尔比为1:1.13;EPSⅡ-1的单糖组成为果糖、葡萄糖和一个不确定的糖,摩尔比为1:1.91.有效地分离纯化了淫羊藿多糖,这为淫羊藿多糖的广泛应用奠定了实验基础.     

Preliminary studies on the composition and rheological properties of the extracellular polysaccharide synthesized by pseudomonas PB1 (NCIB 11264)

A microorganism isolated from a carbohydrate-rich industrial effluent synthesized an exocellular slime polysaccharide composed of glucose and galactose in a molar ratio of 7.45 ± 0.68: 1, and two non-carbohydrate substituents acetate (3–4%) and pyruvate (5–9%). Contamination by rhamnose and mannose was detectable in crude polysaccharide samples. Solutions of the polysaccharide were pseudoplastic, but not thixotropic, and formed gels in the presence of certain trivalent cations.     

Study of the extracellular polysaccharides produced by a blue-green alga,Anabaena flos-aquae A-37

Summary Two types of polysaccharides were separated from the extracellular polysaccharide produced by Anabaena flos-aquae A-37 by ion exchange chromatography. The neutral polysaccharide is composed of mainly glucose with minor amounts of xylose in a molar ratio of 8:1. Glucose is believed to constitute the polysaccharide core to which xylose is attached. The acidic polysaccharide is composed of glucose and uronic acid as the major monomers with equal amounts of xylose and ribose as the minor constituents. The molar ratio of the monomers found in the acidic polymer is 6:1:1:10 as glucose: xylose: ribose: uronic acid. Chemical analyses showed that the extracellular polysaccharide consists of more neutral polymer (62%) than the acidic polymer (38%).     

Chemical compositions of cell walls and polysaccharide fractions of spirochetes

Cellular polysaccharide fractions of various representative members of genera of the family Spirochaetaceae were obtained by the ammonium hydroxide extraction method. The sugar composition of the polysaccharide preparations was complex and many kinds of sugars such as rhamnose, fucose, ribose, xylose, mannose, galactose, and glucose were detected in all of the spirochetes tested. Of particular interest was the presence of 4-O-methylmannose as a constituent polysaccharide in members of the genus Leptospira. This sugar was not detected in the polysaccharides of Spirochaeta, Borrelia, and Treponema. The chemical compositions of cell wall fractions were also examined. 4-O-Methylmannose was detected in the cell wall polysaccharides of the genus Leptospira but not in cell walls prepared from the Spirochaeta, Borrelia, and Treponema. The diaminopimelic acid present in cell wall peptidoglycans of the genus Leptospira was meso-diaminopimelic acid (A2pm). The molar ratios of alanine, glutamic acid, A2pm, glycine, muramic acid, and glucosamine in leptospiral cell walls were found to be approximately 2:1:1:1:1:1. In contrast to the Leptospira, the peptidoglycans of genera Spirochaeta, Borrelia, and Treponema contained ornithine (Orn) but not A2pm. Since 4-O-methylmannose and A2pm were found in the cell wall fractions of genus Leptospira but not in Spirochaeta, Borrelia, or Treponema, it was suggested that the chemical compositions of the cell wall might become an important criterion for the chemotaxonomy of Spirochaetales.     

Control of starch and exocellular polysaccharides biosynthesis by gibberellic acid with cells of sweet potato cultured in vitro

The regulation of starch synthesis and exocellular polysaccharide synthesis by GA₃ was studied with cells of sweet potato grown as suspension in glycerol medium. In the presence of GA₃, and under normal cell growth, starch formation was inhibited. The incorporation activity (starch synthesis) from ADP-[¹⁴C] glucose or UDP-[¹⁴C] glucose with GA₃ treated cells was reduced. On the other hand, the synthesis of exocellular polysaccharides composed of glucose, galactose, mannose and arabinose etc., was stimulated and a clear increase of the Man/Ara ratio was observed in the presence of GA₃. These results may indicate that GA₃ affects the regulation of starch synthesis and exocellular polysaccharide synthesis.     

Modeling growth and biochemical activities of Azospirillum spp.

An unstructured mathematical model was developed and used in the evaluation of biochemical activities of four Azospirillum spp. strains grown in batch cultures in a high C/N-ratio medium. The strains were evaluated for their ability to grow on fructose and produce exo-polysaccharide, and to sustain nitrogenase activity by using fructose or polysaccharides. Quantitative expression of the regulation of polysaccharide synthesis and nitrogenase (acetylene reduction) activity from the mineral nitrogen and sugar concentration in the culture medium was achieved. It was found that, during growth, Azospirillum spp. produced significant quantities of exocellular and capsular polysaccharide, whereas after depletion of the carbon source from the culture medium polysaccharides were consumed, especially in A. lipoferum strains. Significant nitrogenase activity was detected during polysaccharide degradation. Oxygen uptake was high during assimilation of fructose and low during polysaccharide degradation.     

Rhizobium leguminosarum exoB mutants are deficient in the synthesis of UDP-glucose 4'-epimerase

Rhizobium leguminosarum bv. viciae Exo- mutant strains RBL5523,exo7::Tn5,RBL5523,exo8::Tn5 and RBL5523,exo52::Tn5 are affected in nodulation and in the syntheses of lipopolysaccharide, capsular polysaccharide, and exocellular polysaccharide. These mutants were complemented for nodulation and for the syntheses of these polysaccharides by plasmid pMP2603. The gene in which these mutants are defective is functionally homologous to the exoB gene of Rhizobium meliloti. The repeating unit of the residual amounts of EPS still made by the exoB mutants of R. leguminosarum bv. viciae lacks galactose and the substituents attached to it. The R. leguminosarum bv. viciae and R. meliloti exoB mutants fail to synthesize active UDP-glucose 4'-epimerase.