Kinetics of production and characterization of the fucose-containing exopolysaccharide from Enterobacter A47

A fucose-containing exopolysaccharide (EPS) was produced by the bacterium Enterobacter A47 using glycerol byproduct from the biodiesel industry. The analysis of kinetic data suggested a partially growth associated EPS synthesis model. Although the EPS was composed of fucose, galactose and glucose at all cultivation stages, their relative proportion has varied considerably during the run. At the beginning (24 h), glucose was the main component (82.4 wt.%), being fucose and galactose minor components (5.0 wt.% and 10.9 wt.%, respectively), while at the end (96 h) it was composed of 26.0 wt.% fucose, 28.9 wt.% galactose and 43.7 wt.% glucose. The acyl groups content and composition have also changed, reaching their maximum content (19.2 wt.%) at the end of the run. Moreover, the molecular weight has increased linearly during the run (from 8 × 10⁵ to 5 × 10⁶). The changes observed in EPS composition and molecular weight have also had an impact upon the polymer's intrinsic viscosity, as shown by its linear increase from 3.95 to 10.72 dL g⁻¹. The results suggest that the culture might have synthesized at least two distinct EPS, with different sugar composition and average molecular weight, which predominated at different cultivation stages.     

Effect of root exudates on the exopolysaccharide composition and the lipopolysaccharide profile of Azospirillum brasilense Cd under saline stress

The effect of wheat root exudates on the exopolysaccharide (EPS) composition and the lipopolysaccharide (LPS) profile of Azospirillum brasilense Cd under saline stress was studied. EPS of A. brasilense Cd was composed of glucose (47%), mannose (3%), xylose (4%), fucose (28%), rhamnose (6%), arabinose (1%) and galactose (11%). Under saline stress, A. brasilense produced a totally different EPS, composed mainly of galactose. Root exudates induced changes in A. brasilense EPS composition only under normal conditions, consisting of higher amounts of arabinose and xylose compared with EPS of bacteria grown without root exudates. No changes were induced by root exudates when A. brasilense was grown under saline stress. Additionally, root exudates induced changes in the LPS profile, both under normal and stress conditions.     

Exopolysaccharides, proteins and lipids in Pleurotus pulmonarius submerged culture using different carbon sources

For many years mushrooms have been consumed and appreciated by their nutritional value, and medicinal properties. The traditional mushroom cultivation takes too long and the macrofungi biotechnology has not been explored in its full potential yet. The goal of this work was to observe if different carbon sources could improve the yield and diversify fungi nutrient composition in submerged culture.Pleurotus pulmonarius mycelia and exopolysacharide productions were evaluated using glucose, galactose, xylose and arabinose. The mycelia yield varied depending on the culture medium, and galactose showed to be the best carbon source to produce EPS. Samples that showed the highest protein contents were grown with xylose (19.44%) and arabinose (26.05%). Furthermore, the biomass cultivated with these carbohydrates and with galactose showed five essential amino acids. All cultured biomass showed low lipid contents (∼1%), being composed mainly of unsaturated fatty acids. All EPS fractions showed as main structures glucans and mannogalactans.     

Isolation and characterization of mucous exopolysaccharide (EPS) produced by Vibrio furnissii strain VB0S3

Marine bacterial strains were isolated from coastal regions of Goa and screened for the strains that produce the highest amount of mucous exopolysaccharide (EPS). Our screening resulted in the identification of the strain Vibrio furnissii VB0S3 (hereafter called VB0S3), as it produced the highest EPS in batch cultures during the late logarithmic growth phase. The isolate was identified as VB0S3 based on morphological and biochemical properties. Growth and EPS production were studied in mineral salts medium supplemented with NaCl (1.5%) and glucose (0.2%). The exopolymer was recovered from the culture supernatant by using three volumes of cold ethanol precipitation and dialysis procedure. Chemical analyses of EPS revealed that it is primarily composed of neutral sugars, uronic acids, and proteins. Fourier-transform infrared (FT-IR) spectroscopy revealed the presence of carboxyl, hydroxyl, and amide groups, which correspond to a typical heteropolymeric polysaccharide, and the EPS also possessed good emulsification activity. The gas chromatographic analysis of an alditol-acetate derivatized sample of EPS revealed that it was mainly composed of galactose and glucose. Minor components found were mannose, rhamnose, fucose, ribose, arabinose, and xylose. EPS was readily isolated from culture supernatants, which suggests that the EPS was a slime-like exopolysaccharide. This is the first report of exopolysaccharide characterization that describes the isolation and characterization of an EPS expressed by Vibrio furnissii strain VB0S3. The results of the study contribute significantly and go a long way towards an understanding of the correlation between growth and EPS production, chemical composition, and industrial applications of the exopolysaccharide in environmental biotechnology and bioremediation.     

STRUCTURE OF THE CAPSULAR AND EXTRACELLULAR POLYSACCHARIDES PRODUCED BY THE DESMID SPONDYLOSIUM PANDURIFORME (CHLOROPHYTA)1

The filamentous desmid Spondylosium panduriforme (Heimerl) Teiling var. panduriforme f. limneticum (West & West) Teiling (Desmidiaceae), strain 072CH-UFCAR, is surrounded by a well-defined, mucilaginous capsule consisting of a capsular polysaccharide (CPS). This microalga also produces an extracellular polysaccharide (EPS), which can be isolated from the culture medium. Analysis of the carbohydrate composition of the two polymers by gas chromatography showed that they were different. Both were composed, of galactose, fucose, xylose, arabinose, rhamnose, and glucose but in different amounts. For example, glucuronic acid accounts for 24% of the EPS material but only traces were found in the CPS. Significant differences were also found during methylation analysis. Fucose appeared to have a higher degree of branching in the EPS than in the CPS. These branches were located on C-3 and could be the position for the attachment of the glucuronic acid units in the EPS. The glucuronic acid was present as 1→4-linked and terminal units. A possible explanation for the formation of the EPS is suggested.     

The extracellular proteoglycan produced by Rhodella grisea

Highly viscous extracellular proteoglycan (EPG) has been isolated from culture medium of the unicellular red alga Rhodella grisea (Rhodophyceae) by ethanol precipitation. EPG was composed of xylose (29.3%), 3-O-methyl-xylose (26.0%), uronic acids (17.1%), rhamnose (14.4%), galactose (7.5%), glucose (3.9%), arabinose (1.4%) and mannose (0.4%), and traces of fucose, 4-O-methyl-xylose and 2,3-di-O-methyl-rhamnose or fucose. In addition, the polymer contained proteins (13.1%), sulphates and 13C-CP MAS spectra indicated the presence of acetyl and succinyl groups. The molecular mass was estimated to be 136,000. Ion-exchange chromatography afforded five fractions differing in composition of neutral sugars, uronic acids, and protein content indicating thus the complex structure of the EPG.     

Emulsifying behaviour and rheological properties of the extracellular polysaccharide produced by Pseudomonas oleovorans grown on glycerol byproduct

The functional properties of a novel extracellular polysaccharide (EPS) produced by Pseudomonas oleovorans grown on glycerol byproduct, generated by the biodiesel industry, were investigated. The EPS is a high molecular weight (4.6 × 10⁶) heteropolysaccharide, composed by neutral sugars (galactose, 68%; mannose, 17%; glucose, 13%; rhamnose, 2%; fucose, 4%) and acyl groups (3.04%). This biopolymer has pseudoplastic fluid behaviour in aqueous media. The apparent viscosity was stable for the pH range 2.9–7.1 and NaCl concentrations up to 1.0 M. Though the apparent viscosity decreased at high temperatures, at alkaline conditions and at NaCl concentrations of 2.0 M, pseudoplastic fluid behaviour was retained. The EPS was capable of stabilizing water emulsions with several hydrophobic compounds, including hydrocarbons, vegetable and mineral oils. It retained its emulsifying activity during exposure to wide temperature (30–50 °C) and pH (2–12) variations, as well as to the presence of NaCl at concentrations as high as 2.0 M.     

Cell wall formation in zoospores of Allomyces arbuscula

Carbohydrate composition was determined in isolated cell walls of meiospores of Allomyces arbuscula after incubation for 15 min (encysted meiospores: cysts), 150 min (germlings: cysts + rhizoids) and 24 h (cysts + rhizoids + hyphae). The principal constituent in all cell wall samples is chitin, accounting for about 75% of the recovered carbohydrates. In addition, cell walls of all stages examined contain polysaccharides which release galactose, glucose, mannose, arabinose, xylose, fucose, and rhamnose on acid hydrolysis. While different developmental stages show minor quantitative changes in chitin, the ratio of galactose to glucose decreases sharply during differentiation of ungerminated cysts into germlings with rhizoids and hyphae. The increase in glucose is accompanied by a decrease in the amount of xylose and/or fucose and of galactose.List of Abbreviation TFA trifluoroacetic acid     

Isolation and characterization of exopolysaccharide produced by Vibrio harveyi strain VB23

AIMS: The aim of the study was to isolate and characterize exopolysaccharide (EPS) produced by Vibrio harveyi strain VB23. METHODS AND RESULTS: Growth and EPS production by V. harveyi strain VB23, was studied in mineral salts medium supplemented with NaCl (1.5%) and glucose (0.2%). The rate of EPS production in batch cultures was highest during the late log phase of growth when compared with stationary growth phase. The exopolymer was recovered from the culture supernatant by using a cold ethanol precipitation-dialysis procedure. Chemical analyses of EPS revealed that it is primarily composed of neutral sugars, uronic acids, proteins and sulfates. The purified EPS revealed prominent functional reactive groups, such as hydroxyl, carboxylic and amides, which correspond to a typical heteropolymeric polysaccharide and the EPS, also possessed good emulsification activity. The gas chromatographic analysis of an alditol acetate-derivatized sample of EPS revealed that it is composed primarily of galactose and glucose. Minor components found were rhamnose, fucose, ribose, arabinose, xylose and mannose. CONCLUSIONS: The EPS produced by V. harveyi strain VB23 is a heteropolysaccharide possessing good emulsification activity. EPS was readily isolated from culture supernatants, which suggests that the EPS was a slime-like EPS. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of EPS characterization in luminous V. harveyi bacteria, which describes the isolation and characterization of an EPS expressed by V. harveyi. The results of the study contributes significantly towards an understanding of the chemical composition and applications of the EPS in environmental biotechnology and bioremediation.     

Structure of extracellular polysaccharide produced by lignin-degrading fungus Phlebia radiata in liquid culture

The extracellular material (EM) produced by the white rot fungus Phlebia radiata cultured in an N-limited liquid medium was studied. Carbohydrate analysis showed maximum concentration of glucose as the major monosaccharide component of EM was found on postinoculation day 9. Beyond day 9 of cultivation the proportion of glucose decreased suggesting that the glucan component of EM had been further metabolized. The analysis of EM at day 9 revealed the presence of the following monosaccharides (in relative %): glucose (62); galactose (16); mannose (13); xylose (4); and fucose (5). The carbohydrate analysis together with the presence of protein in EM corresponds to a mixture of glucan and glycoprotein. Purification by trypsin treatment yielded an enriched glucose-containing extracellular polysaccharide (EPS). Methylation analysis identified EPS as (1-3)-beta-D-glucan highly branched at C-6. The structure of the glucan was confirmed by 13C-NMR spectroscopy. The results suggest that P. radiata's EPS is entangled with a glycoprotein in a complex that makes the extracellular sheath surrounding the hyphae.     

RELATIVE INCREASE OF DEOXY SUGARS DURING MICROBIAL DEGRADATION OF AN EXTRACELLULAR POLYSACCHARIDE RELEASED BY A TROPICAL FRESHWATER THALASSIOSIRA SP. (BACILLARIOPHYCEAE)1

The aim of this study was to characterize the extracellular polysaccharides (EPS) released by a freshwater Thalassiosira sp. (Bacillariophyceae) and evaluate their degradation by heterotrophic microbial populations from the same habitat of Thalassiosira sp., a tropical eutrophic reservoir. The EPS were purified by anion exchange column chromatography, the monosaccharide composition was determined by GC, and the linkages of the monosaccharides by GC‐MS. The EPS is a mannose‐rich heteropolysaccharide composed of two different acidic fractions. Both of these fractions are composed of mannose, rhamnose, fucose, xylose, galactose, glucose, glucuronic acid, and N‐acetyl glucosamine but with different proportions. N‐acetyl galactosamine occurs only in fraction 1 and galacturonic acid only in fraction 2. We monitored the concentrations of the monosaccharides in the EPS during its degradation using pulse amperometric detection in an HPLC. The decay patterns of the monosaccharides were varied and the deoxy sugars, fucose and rhamnose, were degraded at a slower rate than the other components, increasing their relative concentrations and the hydrophobic feature of the EPS. The possibility of a selective degradation, which enhances the stickiness of the EPS, promoting transparent exopolymeric particles and aggregate formation, is discussed based on the literature data.     

Characterization of an exopolysaccharide produced by a marine Enterobacter cloacae

An exopolysaccharide producing marine bacterium, Enterobacter cloacae, was isolated from marine sediment collected from Gujarat coast, India. Chemical investigation of exopolysaccharide (EPS 71 a) revealed that this exopolysaccharide was an acidic polysaccliaride containing high amount of uronic acid, fucose and sulfate which is rare for bacterial exopolysaccharides. EPS 71a was found to have fucose, galactose, glucose and glucuronic acid in a molar ratio of 2: 1: 1: 1.     

Characterization and fouling properties of exopolysaccharide produced by Klebsiella oxytoca

Klebsiella oxytoca produced a type of exopolysaccharide (EPS) with the average molecular weight (Mw) of 116,018 Da and the average size of 260 nm. The EPS monosaccharide components contained rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose and the molar ratio among them was 0.033:0.0411:0.0147:0.0051:0.2393:0.0986:0.1304. Typical EPS absorption peaks in FT-IR spectrum and pseudoplastic properties were also revealed. The polyvinylidenefluoride (PVDF) membrane showed a relatively larger flux decline resulted from the EPS fouling. The EPS filtration was dominated by more than one mechanism at the beginning phase and mainly by the cake formation at the later phase for both membranes. The pore blocking resistance had a predominant contribution to the filtration resistance and the cake resistance played a secondary role for both the membranes. The EPS adsorption resulted in a weak membrane fouling. The PVDF membrane exhibited a larger adsorption resistance than the polypropylene (PP) membrane.     

小球藻糖蛋白的分离、纯化和结构分析

采用柱层析分离纯化小球藻糖蛋白,并对其进行结构分析。结果表明,小球藻糖蛋白为白色粉末,产率为鲜藻的0．28％,易溶于水,分子量约为65,000Da,属O-连接方式,蛋白质含量为12．01％,糖链部分含有岩藻糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖。     

Novel polysaccharide produced by Azotobacter vinelandii isolated from plant rhizosphere

Summary A strain of Azotobacter vinelandii MTCC 2460 has been isolated from the rhizosphere of the rhizomes of lotus, which produces a novel exopolysaccharide (EPS) having a sugar composition of glucose : galactose : fucose: glucoronic acid (2.2 : 2.7 : 5.6 : 1.6). This composition has not been reported for any species belonging to this genus. The EPS gives high viscosity comparable to xanthan under specific conditions.     

Physicochemical properties and membrane biofouling of extra-cellular polysaccharide produced by a Micrococcus luteus strain

The physicochemical properties of the extra-cellular polysaccharide (EPS) produced by a Micrococcus luteus strain, a dominating strain isolated from membrane biofouling layer, were determined in this study. The EPS isolated from this strain was measured to have an average molecular weight of 63,540 Da and some typical polysaccharide absorption peaks in Fourier transform infrared spectrum. Monosaccharide components of the EPS contained rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose in a molar ratio of 0.2074:0.0454:0.0262:0.0446:1.7942:1.2086:0.4578. Pseudo plastic properties were also observed for the EPS through the rheological measurement. The EPS was further characterized for its behavior to cause membrane flux decline. The results showed that both flux declines for polyvinylidenefluoride (PVDF) and polypropylene membranes became more severe as EPS feed concentration increased. A higher irreversible fouling for the PVDF membrane suggested that the EPS had the larger fouling potential to this microfiltration membrane.     

Production of extracellular polysaccharide by Bacillus megaterium RB-05 using jute as substrate

Bacillus megaterium RB-05 was grown on glucose and on “tossa-daisee” (Corchorus olitorius)-derived jute, and production and composition of extracellular polysaccharide (EPS) were monitored. An EPS yield of 0.065 ± 0.013 and of 0.297 g ± 0.054 g⁻¹ substrate after 72 h was obtained for glucose and jute, respectively. EPS production in the presence of jute paralleled bacterial cellulase activity. High performance liquid chromatography (HPLC), matrix assisted LASER desorption/ionization-time of flight (MALDI-ToF) mass spectroscopy, and fourier transform infrared (FT-IR) spectroscopy demonstrated that the EPS synthesized in jute culture (JC) differed from that synthesized in glucose mineral salts medium (GMSM). While fucose was only a minor constituent (4.9 wt.%) of EPS from GMSM, it a major component (41.9 wt.%) of EPS synthesized in JC. This study establishes jute as an effective fermentation substrate for EPS production by a cellulase-producing bacterium.     

Purification of the influenza hemagglutinin glycoprotein and characterization of its carbohydrate components.

Hemagglutinin from influenza A/PR8 virus was purified after treatment of the virus with sodium deoxycholate followed by extraction with tri-n-butyl phosphate. This fully disrupted the virus while preserving hemagglutinating activity. The hemagglutinin was obtained in the form of small aggregates that could be separated from other viral components. Purified hemagglutinin was hydrolyzed to determine carbohydrate composition and digested with Pronase to analyze oligosaccharide structures. Sugars present in the hemagglutinin were galactose, mannose, fucose, and glucosamine in molar rates of about 6:11:2:5, and these comprised 16% of the hemagglutinin glycoprotein. Oligosaccharides obtained from virus included a major component of a molecular weight of 2,800, composed of glucosamine, galactose, mannose, and fucose, and a minor heterogenous component of a molecular weight of 1,500 to 2,000, containing predominantly mannose. The 2,800-molecular-weight oligosaccharide was a constituent of the hemagglutinin, and treatment of this large oligosaccharide with specific exo-glycosidases demonstrated the presence of terminal galactose and fucose and allowed the deduction of a general structure for this component.     

Isolation and structural characterization of a polysaccharide FCAP1 from the fruit of Cornus officinalis

A water-soluble polysaccharide, FCAP1, was isolated from an alkaline extract from the fruits of Cornus officinalis. Its molecular weight was 34.5 kDa. Monosaccharide composition analysis revealed that it was composed of fucose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 0.29:0.19:1.74:1:3.30:1.10. On the basis of partial acid hydrolysis and methylation analysis, FCAP1 was shown to be a highly branched polysaccharide with a backbone of β-(1→4)-linked-glucose partially substituted at the O-6 position with xylopyranose residues. The branches were composed of (1→3)-linked-Ara, (1→4)-linked-Man, (1→4,6)-linked-Man, (1→4)-linked-Glc, and (1→2)-linked-Gal. Arabinose, fucose, and galactose were located at the terminal of the branches. The structure was further elucidated by a specific enzymatic degradation with an endo-β-(1→4)-glucanase and MALDI-TOF-MS analysis. Oligosaccharides generated from FCAP1 indicated that FCAP1 contained XXXG-type and XXG-type xyloglucan fragments.     

The preparation and chemical composition of the multiple forms of beta-glucuronidase from the female rat preputial gland.

Beta-Glucuronidase isolated from the preputial gland of the female rat has previously been shown to be a tetrameric glycoprotein. We have now separated the enzyme into several molecular forms by chromatography on hydroxylapatite columns. The three major forms (A, B, and C) have a very similar or identical amino acid composition, and kinetic and stability studies on forms B and C disclosed no differences between these two forms. However, from C contained much more carbohydrate than forms A and B, which were very similar in carbohydrate composition. The sugars in forms A and B are mannose (2.8%), glucosamine (1.9%), fucose (0.2%), galactose (0.16%), and glucose (0.17%). Form C is a little higher in mannose content, but, more distinctively, is much richer in fucose (0.6%), galactose (1.1%), and glucose (1.5%). The presence of glucose was established by paper chromatography as well as by gas-liquid chromatography, and several special experiments were performed to rule out the possibility that this hexose was present in a persistent contaminant. Direct chemical analysis for sialic acid consistently showed the absence of this sugar in the enzyme. The fact that the carbohydrate-protein linkage is alkali-stable suggests that the linkage involves an asparaginyl-N-acetylglucosamine residue. The NH2-terminal amino acid in the polypeptide chain is leucine.