Structural and biosynthetic studies on xanthan by 13C-n.m.r. spectroscopy

Horton, Derek; Mols, Ole; Wałaszek, Zbigniew; Wernau, William C.

doi:10.1016/s0008-6215(00)90467-1

Cited by 27 publications

(20 citation statements)

References 12 publications

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“…The 13 C NMR spectrum of the degraded xanthan solution (M w = 1.4 × 10 5 g/mol after 15 h of sonification) allows for a partial assignment of resonance lines to individual carbon positions of the polysaccharide chain following the interpretations by Horton et al [13] and Gamini et al [14] (Fig. 6a).…”

Section: Nmr Measurementsmentioning

confidence: 96%

Binding of bivalent cations by xanthan in aqueous solution

Bergmann

Furth

Mayer

2008

International Journal of Biological Macromolecules

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Section: Nmr Measurementsmentioning

confidence: 96%

Binding of bivalent cations by xanthan in aqueous solution

Bergmann

Furth

Mayer

2008

International Journal of Biological Macromolecules

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“…A temperatura de dissolução afeta grandemente a viscosidade por controlar a conformação molecular. A molécula goma xantana parece ter duas conformações, helicoidal e randômica, dependendo da temperatura de dissolução (Horton et al, 1985;García-Ochoa e Casas, 1994;García-Ochoa et al, 2000).…”

Section: Propriedades Reológicas Da Goma Xantanaunclassified

Goma xantana: produção, recuperação, propriedades e aplicação

Luvielmo¹,

Scamparini²

2009

ETE

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Resumo AbstractAs bactérias pertencentes ao gênero Xanthomonas podem produzir goma xantana, um polissacarídeo de enorme interesse para as indústrias de alimentos, farmacêuticas e de petróleo. A goma apresenta capacidade de formar soluções viscosas e géis hidrossolúveis que lhe fornece propriedades reológicas únicas. Atualmente toda a goma xantana consumida no Brasil, provém de importações, porém o Brasil tem um grande potencial para a fabricação deste polímero em escala industrial, já que temos matéria-prima básica para sua produção: açúcar, extrato de levedura e álcool do setor sucro-alcooleiro. O objetivo dessa revisão é atualizar os conhecimentos sobre a produção, recuperação, propriedades e aplicação da goma xantana.The bacteria belonging to the gender Xanthomonas can produce xanthan gum, a polysaccharide of enormous interest for food, pharmaceutical and petroleum industries. The gum presents capacity to form viscous solutions and gels hydrosoluble that supplies its unique reological properties. Actually, all xanthan gum consumed in Brazil, becomes from imports, however Brazil has a great potential for production of this polymeric in industrial scale, since we have basic raw material for its production: sugar, yeast extract and alcohol of sugar-alcohol section. The objective of this review is to update the knowledge about production, recovery, properties and application of the xanthan gum.Palavras-chave: goma xantana, produção, aplicação.

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“…Because of its unique rheological properties such as high viscosity and pseudoelasticity (43), xanthan has a potential application in industrial production processes (4,47). Detailed knowledge of the chemistry and biosynthesis of xanthan has accumulated over the years (26,28,29,40). The chemical structure of this acidic heteropolysaccharide is well known.…”

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confidence: 99%

Genetics of xanthan production in Xanthomonas campestris: the xanA and xanB genes are involved in UDP-glucose and GDP-mannose biosynthesis

et al. 1992

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The nucleotide sequence of a 3.4-kb EcoRI-PstI DNA fragment of Xanthomonas campestris pv. campestris revealed two open reading frames, which were designated xanA and xanB. The genes xanA and xanB encode proteins of 448 amino acids (molecular weight of 48,919) and 466 amino acids (molecular weight of 50,873), respectively. These genes were identified by analyzing insertion mutants which were known to be involved in xanthan production. Specific tests for the activities of enzymes involved in the biosynthesis of UDP-glucose and GDP-mannose indicated that the xanA gene product was involved in the biosynthesis of both glucose 1-phosphate and mannose 1-phosphate. The deduced amino acid sequence of xanB showed a significant degree of homology (59%) to the phosphomannose isomerase of Pseudomonas aeruginosa, a key enzyme in the biosynthesis of alginate. Moreover, biochemical analysis and complementation experiments with the Escherichia coli manA fragment revealed that xanB encoded a bifunctional enzyme, phosphomannose isomerase-GDP-mannose pyrophosphorylase.

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Structural and biosynthetic studies on xanthan by 13C-n.m.r. spectroscopy

Cited by 27 publications

References 12 publications

Binding of bivalent cations by xanthan in aqueous solution

Binding of bivalent cations by xanthan in aqueous solution

Goma xantana: produção, recuperação, propriedades e aplicação

Genetics of xanthan production in Xanthomonas campestris: the xanA and xanB genes are involved in UDP-glucose and GDP-mannose biosynthesis

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