Molecular Origin for the Thermal Stability of S-88 Gum Produced by Pseudomonas ATCC 31554

Tako, Masakuni; Tamaki, Hiroyuki

doi:10.1295/polymj.37.498

Cited by 13 publications

(15 citation statements)

References 36 publications

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“…The models proposed for welan (Scheme 2), rhamsan (Scheme 3) and S-657 (Scheme 4) gum corresponded to a single-stranded helix. We also demonstrated possible intramolecular associations of S-88 gum [58] …”

Section: Introductionmentioning

confidence: 60%

“…The sample was prepared using the same methods as reported in previously, which are as follows: heated at 90˚C for 20 min, cooled at room temperature, centrifuged at 23,000 g for 1 h, and filtered through Celite 545 (which had been pre-treated with boiling 3 M HCl for 30 min and washed with distilled water until reaching pH 6.0) [51]- [54] [58]. In the presence of 0.05% KCl, ethanol (2 vol.)…”

Section: Methodsmentioning

confidence: 99%

“…To compare the rheological behaviors of S-198 gum to those of gellan (native and deacylated), welan, rhamsan (native and deacetylated), and S-88 gum, the viscosity and dynamic viscoelasticity were measured under the same conditions as in of our previous studies [5] [6] [51]- [54] [58]. Although the flow curves of S-198 gum approximated to shear-thinning behavior at a concentration of 0.1%, they shifted to high shear stress and approximated plastic behavior above 0.3% at 25˚C, as shown in Figure 1.…”

Section: Flow Characteristicsmentioning

confidence: 99%

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Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Tako¹,

Kitajima²,

Yogi³

et al. 2016

ABC

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The structure-function relationship of a gellan family of polysaccharides, S-198 gum produced by Alcaligenes ATCC31853 was investigated in terms of rheological aspects. The flow curves of S-198 gum showed plastic behavior above 0.3%. Gelation did not occur in S-198 gum solution at low temperature (0˚C), even at 0.8%. Both the viscosity and the elastic modulus remained constant with increasing temperature up to 80˚C. The elastic modulus decreased a little with the addition of CaCl2 (6.8 mM), but then once again remained constant up to 80˚C. The highest elastic modulus was observed for deacylated gellan gum with the addition of CaCl 2 and increased slightly with increasing temperature up to 80˚C, which was considered to be a transition temperature, after which it decreased rapidly. The elastic modulus of S-198 gum in the presence of urea (4.0 M) was lower than that in aqueous solution at low temperature (0˚C), but remained constant with increasing temperature up to 80˚C. The intramolecular associations, (hydrogen bonding and van der Waals forces of attraction), of S-198 gum molecules in aqueous solutions were proposed. The gellan family of polysaccharides, S-198, S-88, S-657, rhamsan, welan and gellan gum, provided a good opportunity to investigate the structure-function relationship for polysaccharides.

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Section: Introductionmentioning

confidence: 60%

Section: Methodsmentioning

confidence: 99%

Section: Flow Characteristicsmentioning

confidence: 99%

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Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Tako¹,

Kitajima²,

Yogi³

et al. 2016

ABC

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“…The transition temperature is the temperature above which the secondary association dissociates. The results indicate that rhamnan sulfate molecules have a thermostable characteristic in aqueous solution as in gellan family of polysaccharides [29][30][31][32][33].…”

Section: Elastic Modulusmentioning

confidence: 90%

“…Furthermore, we proposed intramolecular associations for the gellan family of polysaccharides, welan [29], rhamsan [30], S-657 [31], S-88 [32] and S-198 [33] gum where methyl groups of the L-rhamnosyl residue plays an important role, leading to their thermal stability in aqueous solutions.…”

Section: Introductionmentioning

confidence: 99%

Structure-Function Relationship of Rhamnan Sulfate Isolated from Commercially Cultured Edible Green Seaweed, <i>Monostroma nitidum</i>

Tako¹

2017

AJAC

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Abstract:The green seaweed, Monostroma nitidum, is widespread in Japan. In Okinawa Prefecture, production of seaweed is performed using culture-nets that are seeded artificially. The annual production of the algae in Okinawa was approximately 100t in 2016. Recently, because Monostroma nitidum is used in salads, soups and other items, its utilization in the food industry increased. The algae contain a soluble polysaccharide, rhamnan sulfate. To estimate the applicability of a rhamnan sulfate as a food additive or non-food additives, we investigated the rheological properties of the polymer that was isolated from commercially cultured Monostroma nitidum using a rheogoniometer. A soft gelation occurred at a concentration of 4.0%, and the elastic modulus stayed at a constant value after the temperature to 50°C, which was estimated to be a transition temperature, then decreased rapidly with further increase in temperature. Although a small decrease in elastic modulus was observed with the addition of urea (4.0 M), it remained constant with an increase in temperature up to 60°C, and then decreased. An increase in the elastic modulus was observed in a 0.05 M NaOH solution and soft gelation occurred. The elastic modulus remained large during the increase in temperature even at 90°C. A soft gelation also occurred when rhamnan sulfate was dissolved in a Tris buffer (pH 8.0) solution. The possible mode of intra-and intermolecular associations within and between rhamnan sulfate molecules were discussed.

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Carbohydrates

Dräger

Krause

Möller

et al. 2011

Handbook of Biodegradable Polymers

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7 156 7 Carbohydrates AlginateAlginate belongs to the family of linear (unbranched), nonrepeating copolymers. It consists of variable amounts of βd -mannuronic acid (M) and its C5 -epimer α -lguluronic acid (G) which are linked via β -(1,4) -glycosidic bonds. The glycosidic bonds of mannuronic acid are connected to the following unit by a diequatorial 4 C 1 linkage, while guluronic acids are diaxial 1 C 4 linked. Alginate can be regarded as a true block copolymer composed of homopolymeric M and G regions, called M -and G -blocks, respectively, interspersed with regions of alternating structure [5] (Scheme 7.1 ).The physicochemical properties of alginate have been found to be highly affected by the M/G ratio as well as by the structure of the alternating zones. In terms of specifi c medical applications, alginate materials with a high guluronic acid ratio exhibit a much better compatibility [6] . The fi rst protocol to hydrolyze the glycosidic bonds of alginate has been published by Haug et al. in the 1960s and is based on a pH -dependent acid -catalyzed hydrolysis, which leads to a fragmentation of the polymeric chain. Breaking the glycosidic bonds of both building blocks selectively could be achieved due to different p K a values of mannuronic acid (p K a : 3.38) and guluronic acid (p K a : 3.65) [7] . Therefore, polyguluronic acid can be separated by precipitation in aqueous conditions after protonating the carboxyl groups.Alginate can be extracted from marine brown algae or it can be produced by bacteria. Both species produce alginate as an exopolymeric polysaccharide during their growth phase. Isolated alginates from marine brown algae like Laminaria hyperborea or lessonia , gained by harvesting brown seaweeds from coastal regions, tend to vary in their constitution due to seasonal and environmental changes. Like chitin in shellfi sh, alginates in algae have structure -forming functions. This is due to the intracellular formed gel matrix, which is responsible for mechanical strength, fl exibility, and form. Alginates in bacteria are synthesized only by two genera, Pseudomonas and Azotobacter , and have been extensively studied over the last 40 years. While primarily synthesized in the form of polymannuronic acid, the biosynthesis undergoes chemical modifi cations comprising acetylation and epimerization, which occurs during periplasmic transfer and before fi nal export through the outer membrane. Extracted alginate from Pseudomonas contains only M blocks Scheme 7.1 Chemical structure of alginate with mannuronic acid (M), alternating, and guluronic acid (G) blocks.

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Molecular Origin for the Thermal Stability of S-88 Gum Produced by Pseudomonas ATCC 31554

Cited by 13 publications

References 36 publications

Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Structure-Function Relationship of Rhamnan Sulfate Isolated from Commercially Cultured Edible Green Seaweed, <i>Monostroma nitidum</i>

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Molecular Origin for the Thermal Stability of S-88 Gum Produced by Pseudomonas ATCC 31554

Cited by 13 publications

References 36 publications

Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

Structure-Function Relationship of Rhamnan Sulfate Isolated from Commercially Cultured Edible Green Seaweed, &lt;i&gt;Monostroma nitidum&lt;/i&gt;

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Structure-Function Relationship of Rhamnan Sulfate Isolated from Commercially Cultured Edible Green Seaweed, <i>Monostroma nitidum</i>