Size, structure and scaling relationships in glycogen from various sources investigated with asymmetrical flow field-flow fractionation and 1H NMR

Fernandez, Céline; Rojas, Cinthia Carola; Nilsson, Lars

doi:10.1016/j.ijbiomac.2011.05.016

Cited by 42 publications

(13 citation statements)

References 43 publications

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“…The spectrum of glycogen exhibited line broadening, which is common for high-molecular-weight polysaccharides, due to the decrease in the motional rate of larger molecules in solution (30). The DB calculated using the integration of the two peaks was 0.081, close to a previously reported result (31). The previously described (1¡4,1¡6)-␣-glucan in YCWG (32) was confirmed, as indicated by the doublet at 5.134 and 5.094 ppm (Fig.…”

Section: Resultssupporting

confidence: 86%

Mechanistic Study of Utilization of Water-Insoluble Saccharomyces cerevisiae Glucans by Bifidobacterium breve Strain JCM1192

Keung

Sham

et al. 2017

Appl Environ Microbiol

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Bifidobacteria exert beneficial effects on hosts and are extensively used as probiotics. However, due to the genetic inaccessibility of these bacteria, little is known about their mechanisms of carbohydrate utilization and regulation. Bifidobacterium breve strain JCM1192 can grow on water-insoluble yeast (Saccharomyces cerevisiae) cell wall glucans (YCWG), which were recently considered as potential prebiotics. According to the results of 1 H nuclear magnetic resonance (NMR) spectrometry, the YCWG were composed of highly branched (1¡3,1¡6)-␤-glucans and (1¡4,1¡6)-␣-glucans. Although the YCWG were composed of 78.3% ␤-glucans and 21.7% ␣-glucans, only ␣-glucans were consumed by the B. breve strain. The ABC transporter (malEFG1) and pullulanase (aapA) genes were transcriptionally upregulated in the metabolism of insoluble yeast glucans, suggesting their potential involvement in the process. A nonsense mutation identified in the gene encoding an ABC transporter ATP-binding protein (MalK) led to growth failure of an ethyl methanesulfonate-generated mutant with yeast glucans. Coculture of the wild-type strain and the mutant showed that this protein was responsible for the import of yeast glucans or their breakdown products, rather than the export of ␣-glucancatabolizing enzymes. Further characterization of the carbohydrate utilization of the mutant and three of its revertants indicated that this mutation was pleiotropic: the mutant could not grow with maltose, glycogen, dextrin, raffinose, cellobiose, melibiose, or turanose. We propose that insoluble yeast ␣-glucans are hydrolyzed by extracellular pullulanase into maltose and/or maltooligosaccharides, which are then transported into the cell by the ABC transport system composed of MalEFG1 and MalK. The mechanism elucidated here will facilitate the development of B. breve and water-insoluble yeast glucans as novel synbiotics.IMPORTANCE In general, Bifidobacterium strains are genetically intractable. Coupling classic forward genetics with next-generation sequencing, here we identified an ABC transporter ATP-binding protein (MalK) responsible for the import of insoluble yeast glucan breakdown products by B. breve JCM1192. We demonstrated the pleiotropic effects of the ABC transporter ATP-binding protein in maltose/maltooligosaccharide, raffinose, cellobiose, melibiose, and turanose transport. With the addition of transcriptional analysis, we propose that insoluble yeast glucans are broken down by extracellular pullulanase into maltose and/or maltooligosaccharides, which are then transported into the cell by the ABC transport system composed of MalEFG1 and MalK. The mechanism elucidated here will facilitate the development of B. breve and water-insoluble yeast glucans as novel synbiotics.

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Section: Resultssupporting

confidence: 86%

Mechanistic Study of Utilization of Water-Insoluble Saccharomyces cerevisiae Glucans by Bifidobacterium breve Strain JCM1192

Keung

Sham

et al. 2017

Appl Environ Microbiol

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“…Amylose is typically reported to have a molar mass (M) between~10 5 and 10 6 g/mol [2]. Amylopectin is highly branched (4-5 % α(1→ 6) branch linkages [3,4]) and has a very high molar mass (M> 10 7 g/mol [5]). It consists of a large number of α(1→4) linked glucose chains that are interlinked by α(1→6) linkages.…”

Section: Introductionmentioning

confidence: 99%

Development and evaluation of methods for starch dissolution using asymmetrical flow field-flow fractionation. Part I: Dissolution of amylopectin

2015

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We have investigated methods of starch dissolution with the aim of finding an optimum method to completely dissolve starch granules to form a molecularly dissolved starch solution without degradation of the polymers. Glycogen was used as a model molecule for amylopectin, to identify the dissolution conditions under which the degradation of the polymers was limited or not present. Dissolution was performed in water with temperatures up to 200 °C, facilitated by the use of heating in an autoclave or a microwave oven, or in dimethyl sulfoxide (DMSO) at 100 °C. Waxy maize starch was chosen due to its high content of amylopectin and very low content of amylose. The degree of starch dissolution under different conditions was determined enzymatically. The effect of different dissolution conditions on the molar mass and root-mean-square radius of the polymers was determined with asymmetrical flow field-flow fractionation coupled to multi-angle light scattering and differential refractive index (AF4-MALS-dRI) detectors under aqueous conditions. The results suggest that reliable and accurate size separation and characterization of amylopectin can be obtained by dissolution of starch granules in an aqueous environment at 140 °C by autoclaving or in DMSO at 100 °C. The results also clearly show an upper limit for heat treatment of starch, above which degradation cannot be avoided.

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“…Amylopectin contains aprox. 5% of a-1,6 glucosidic branch points [4]. The branch points permit the efficient crystalline packing of the short chain, which forms double helices and are associated into clusters.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic hydrolysis of Canna indica, Manihot esculenta and Xanthosoma sagittifolium native starches below the gelatinization temperature

et al. 2012

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The susceptibility to enzymatic hydrolysis of starch extracted from raw roots of Canna indica, Manihot esculenta and Xanthosoma sagittifolium, grown in Bolivia, were studied below the gelatinization temperature. The granule size and amylose content were as followed: C. indica>M. esculenta>X. sagittifolium. The hydrolysis showed a rapid rate at the initial stage, followed by a progressive decrease thereafter. At 30, 40 and 508C, during the initial stage, the rate of hydrolysis was observed to be influenced by the size of the granules, being the highest for the small sized granules X. sagittifolium, followed by the medium sized granules M. esculenta and the lowest rate was for the large sized granules C. indica starch. During the slow phase, A-type M. esculenta and B-type C. indica showed higher hydrolysis rates than A-type X. sagittifolium. At 608C, a positive correlation was found between the amylose content and the rate of hydrolysis among the starches. Microscopic observations showed a pattern of attack by the enzyme towards C. indica starch granules, suggesting that high amylose content is concentrated around the hilum.

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Size, structure and scaling relationships in glycogen from various sources investigated with asymmetrical flow field-flow fractionation and 1H NMR

Cited by 42 publications

References 43 publications

Mechanistic Study of Utilization of Water-Insoluble Saccharomyces cerevisiae Glucans by Bifidobacterium breve Strain JCM1192

Mechanistic Study of Utilization of Water-Insoluble Saccharomyces cerevisiae Glucans by Bifidobacterium breve Strain JCM1192

Development and evaluation of methods for starch dissolution using asymmetrical flow field-flow fractionation. Part I: Dissolution of amylopectin

Enzymatic hydrolysis of Canna indica, Manihot esculenta and Xanthosoma sagittifolium native starches below the gelatinization temperature

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