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Structure andProperty Engineeringof α-d-GlucansSynthesized byDextransucraseMutants Romain IragueAgnès Rolland‐SabatéLaurence Tarquis2011 год

Structure and Property Engineering of α-d-Glucans Synthesized by Dextransucrase Mutants
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Страница публикацииПубликация в OpenAlex
Аннотация: Seven dextran types, displaying from 3 to 20% α(1→3) glycosidic linkages, were synthesized in vitro from sucrose by mutants of dextransucrase DSR-S from Leuconostoc mesenteroides NRRL B-512F, obtained by combinatorial engineering. The structural and physicochemical properties of these original biopolymers were characterized. When asymmetrical flow field flow fractionation coupled with multiangle laser light scattering was used, it was determined that weight average molar masses and radii of gyration ranged from 0.76 to 6.02 × 108 g·mol–1 and from 55 to 206 nm, respectively. The νG values reveal that dextrans Gcn6 and Gcn7, which contain 15 and 20% α(1→3) linkages, are highly branched and contain long ramifications, while Gcn1 is rather linear with only 3% α(1→3) linkages. Others display intermediate molecular structures. Rheological investigation shows that all of these polymers present a classical non-Newtonian pseudoplastic behavior. However, Gcn_DvΔ4N, Gcn2, Gcn3, and Gcn7 form weak gels, while others display a viscoelastic behavior that is typical of entangled polymer solutions. Finally, glass transition temperature Tg was measured by differential scanning calorimetry. Interestingly, the Tg of Gcn1 and Gcn5 are equal to 19.0 and 29.8 °C, respectively. Because of this low Tg, these two original dextrans are able to form rubber and flexible films at ambient temperature without any plasticizer addition. The mechanical parameters determined for Gcn1 films from tensile tests are very promising in comparison to the films obtained with other polysaccharides extracted from plants, algae or microbial fermentation. These results lead the way to using these dextrans as innovative biosourced materials.
Год издания: 2011
Авторы: Romain Irague, Agnès Rolland‐Sabaté, Laurence Tarquis, Jean Louis Doublier, Claire Moulis, Pierre Monsan, Magali Remaud‐Siméon, Gabrielle Potocki-Véronèse, Alain Buléon
Издательство: American Chemical Society
Источник: Biomacromolecules
Ключевые слова: Polysaccharides Composition and Applications, Polysaccharides and Plant Cell Walls, Microbial Metabolites in Food Biotechnology
Другие ссылки: Biomacromolecules (HTML)
hal.inrae.fr (HTML)
PubMed (HTML)