Дисертації з теми "(1,3;1,4)-β-glucan"
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1
Garcia, Gimenez Guillermo. "Regulation of (1,3;1,4)-β-glucan synthesis in barley (Hordeum vulgare L.)". Thesis, University of Dundee, 2019. https://discovery.dundee.ac.uk/en/studentTheses/fc549364-8ed1-4840-ad6c-b868cfebb28b.
Повний текст джерела
2
Schreiber, Miriam. "Identification of genes involved in (1,3;1,4)-β-glucan synthesis in barley (Hordeum vulgare)". Thesis, University of Dundee, 2016. https://discovery.dundee.ac.uk/en/studentTheses/5e459c3c-9ba7-4fb6-a33b-02577ea185fa.
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3
Agbenorhevi, Jacob Kwaku. "Phase behaviour of oat β-glucan/sodium caseinate mixtures". Thesis, University of Huddersfield, 2011. http://eprints.hud.ac.uk/id/eprint/17475/.
Повний текст джерелаАнотація:
Oat β-glucan is a water soluble polysaccharide which has been approved as a functional bioactive ingredient. In this thesis, β-glucan was successfully isolated from oat flour and samples of different molecular weights were produced. The structural features and molecular weights(Mw) were characterized by 13C–NMR spectroscopy and high performance size-exclusion chromatography, respectively. The rheological properties and microstructure of aqueous oat β-glucan solutions were investigated by rheometry and atomic force microscopy (AFM),respectively. The samples with β-glucan content between 78-86 % on a dry weight basis had Mw, intrinsic viscosity ([η]) and critical coil overlap concentration (c*) in the range of 142 - 2800 x 103 g/mol, 1.7 - 7.2 dL/g and 0.25 - 1.10 g/dL, respectively. The flow and viscoelasticvbehaviour was highly dependent on Mw and on the concentration of the β-glucan solutions. AFM images revealed the formation of cluster or aggregates linked via individual polymer chains scattered heterogeneously throughout the system. The aggregate size was also dependent on molecular weight of the samples and influences the rheological behaviour of β-glucan solutions. The isothermal phase behaviour at 5 oC of β-glucan/sodium caseinate mixtures were investigated by means of phase diagram construction, rheometry, electrophoresis and fluorescence microscopy. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan Mw decreases. Images of the mixtures taken at various biopolymer concentrations revealed phase separation with the presence of β-glucan aggregates,whose size depends on Mw and concentration. At the same protein concentration in the mixtures, the viscosity increases with increasing Mw and concentration of β-glucan. However, the results also revealed that in the state of thermodynamic equilibrium with comparable polymer concentrations in mixture, the lower Mw samples yielded similar or higher viscosity. At equivalent hydrodynamic volume of β-glucan component in the mixture, all the samples exhibited similar viscosity/flow behaviour. A deviation dependent on the protein concentration was observed for the high Mw sample in the concentrated regime due to the size of the β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixture with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved.
4
Granum, Espen. "Metabolism and function of β-1,3-glucan in marine diatoms". Doctoral thesis, Norwegian University of Science and Technology, Faculty of Natural Sciences and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-44.
Повний текст джерелаАнотація:
β-1,3-Glucan (chrysolaminaran) is the principal storage polysaccharide in diatoms (Bacillariophyceae), the major primary producers in the sea. The glucan generally contributes a substantial fraction of the algal biomass, but its level varies markedly in response to growth conditions. The scope of this work was to study the metabolism and function of the polysaccharide in marine diatoms. Axenic cultures of the marine planktonic diatom Skeletonema costatum (Grev.) Cleve were used in the experiments. Glucan metabolism was studied by growing the alga in batch culture, and measuring metabolite fluxes by chemical analyses as well as by 14C tracer technique using labeled bicarbonate. A photobioreactor was developed for strictly controlled growth of microalgae. Fine pH regulation was obtained by relay-activated titration with dilute acid (HCl) and base (NaOH). Irradiance and temperature were also carefully controlled. Batch cultures were grown with a 14:10 h light:dark cycle, and pH curves were recorded during different growth phases.
A new method was developed for the combined determination of β-1,3-glucan and cell wall polysaccharides in diatoms, representing total cellular carbohydrate. The glucan is rapidly extracted by hot dilute H2SO4, and the cell wall polysaccharides are subsequently hydrolyzed by cold 80% H2SO4overnight. Each carbohydrate fraction is finally determined by the phenol-sulphuric acid method. This procedure is simple and rapid compared to previous methods, and applies well to laboratory cultures as well as natural phytoplankton populations dominated by diatoms.
Synthesis and mobilization of β-1,3-glucan in N-limited S. costatum were studied by combined 14C tracer technique and chemical analyses. Radiolabeled bicarbonate was added to the cultures, and 14C incorporation in different metabolites was determined using biochemical fractionation. In a pulse phase, 14C label was mainly incorporated in the glucan fraction (85%) during photosynthesis under nitrogen limitation. Subsequently, a 14C chase was carried out by adding NH4+ and incubating the cells under different light conditions. Radiolabeled glucan decreased significantly (by 26% in the dark, and by 19% in low light) whereas radiolabeled amino acids, proteins and other polysaccharides increased significantly during NH4+ assimilation. Chemical analyses of β-1,3-glucan and cellular free amino acids supported the 14C measurements. Changes in amino acid composition strongly indicated that de novo biosynthesis took place, with a Gln/Glu ratio increasing from 0.4 to 10. This study provides new evidence of β-1,3-glucan supplying carbon skeletons for synthesis of amino acids and protein in diatoms. Mobilization of glucan yields glucose, which is further metabolized by the respiratory pathways to provide precursors as well as energy. The results from the 14C chase also indicated significant synthesis of other polysaccharides or possibly RNA from glucan.
In a different study, dark carbon fixation in N-limited S. costatum was measured using 14C-bicarbonate. Addition of NH4+ resulted in 4-fold increase in carboxylation rate, and biochemical fractionation showed that mainly amino acids were radiolabeled. Chemical analyses confirmed that cellular free amino acids increased rapidly (with increasing Gln/Glu), and showed that cellular glucan decreased significantly (by 28%) during NH4+ assimilation. The results strongly indicate that β-carboxylation provides C4 precursors for amino acid synthesis, and β-1,3-glucan is likely to be the ultimate substrate for β-carboxylation. Moreover, a C/N uptake ratio of 0.33 indicated that β-carboxylation was related to protein synthesis.
A detailed study was made of the production of carbohydrates and amino acids by S. costatum during different growth phases. During exponential growth under diel light conditions, the glucan level oscillated between 17% (end of scotophase) and 42% (end of photophase) of cellular organic carbon, and the corresponding protein/glucan ratio alternated between 2.3 and 0.7. Concurrently, the cellular free amino acid pool oscillated between 8% (end of scotophase) and 22% (end of photophase) of cellular organic nitrogen, and the corresponding Gln/Glu ratio alternated between 0.05 and 2. Depletion of nitrogen from the medium resulted in rapid accumulation of glucan, reaching 75-80% of cellular organic carbon, whereas the cellular nitrogenous components decreased significantly. Consequently, the protein/glucan ratio decreased to <0.1. This study indicates that β-1,3-glucan functions both as a short-term diurnal reserve and a long-term stockpile reserve.
Field investigations by other workers suggest that glucan plays a very active role in the dynamics of natural diatom populations, and the protein/glucan ratio has been used as a sensitive parameter for nutrient status. The glucan dynamics may be involved in physiological control of buoyancy. Glucan accumulation by nutrient-deplete cells causes increased cellular density and sinking below the nutricline. Upon nutrient replenishment and mobilization of glucan, the cells rise toward the surface of the water column, thereby transporting deep nutrients to the euphotic zone. β-1,3-Glucan also seems to play an important role in the development of resting stages in diatoms.
5
Van, der Merwe Laurianne. "UDP-glucose: β-(1-3)-glucan (paramylon) synthase from Euglena gracilis". Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1560.
Повний текст джерелаАнотація:
Thesis (MSc (Plant Biotechnology))--University of Stellenbosch, 2007.The photosynthetic protist Euglena gracilis synthesizes a storage carbohydrate named paramylon, a glucan consisting only of β-(1-3)-glycosidic linkages. The enzyme that produces paramylon is a glycosyltransferase commonly known as paramylon synthase (EC 2.4.1.34; UDP-glucose: 1,3-β-D-glucan 3-β-D-glucosyl transferase). This enzyme uses UDP-glucose as its main substrate. In 2001, Bäumer et al. isolated and partially purified paramylon synthase, but never presented any sequence information. Hence, the main aim of this project was to isolate and characterize the gene(s) coding for the paramylon synthase. Different approaches were taken in order to isolate and characterize the gene(s). In the first part of the study molecular techniques were used to try and identify the gene. The two methods used were library screening and PCR amplification. Different libraries were screened using either functional staining or an affinity probe. The second method concentrated on the use of degenerate oligonucleotides, based on the amino acid sequences of conserved regions from known β-(1-3)-glucan synthase genes from various organisms, to PCR amplify the gene sequence from Euglena. These approaches were not successful in the isolation of the gene(s). In the second part of the study protein purification techniques were used in an attempt to obtain de novo protein sequence from the purified paramylon synthase enzyme. Several protein purification techniques were tried with the most successful being preparative ultra centrifugation followed either by sucrose density centrifugation or product entrapment (a type of affinity purification). These resulted in partial purification of the paramylon synthase protein. The partially purified proteins were separated using polyacrylamide gel electrophoresis, and the polypeptides able to bind the precursor, UDP-glucose, were identified using a radiolabeled isotope of UDP-glucose. These polypeptides were subjected to LC-MS-MS in order to obtain sequence information from them. One tryptic fragment showed high homology to β-(1,3)-glucan synthase genes from different yeasts.
6
Marins, de Sa Roberta. "Study of β-glucan breakdown and endosperm modification during malting of barley". Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/322.
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7
Hancock, Robert D. "Exo-β-(1→3)-glucan (curdlan) biosynthesis by Agrobacterium sp. ATCC 31749". Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/14981.
Повний текст джерелаАнотація:
The present study describes physiological conditions which promote curdlan synthesis, the effect of metabolic inhibitors on production and the nature of the product of Agrobacterium sp. ATCC 31749, a laboratory derivative of a strain originally isolated from soil. Nitrogen depletion in the medium was essential for production, and depletion of sulphur or phosphorus in batch culture did not promote curdlan synthesis. Similarly, initiation of curdlan production was observed when bacteria were transferred to nitrogen free medium but not media free of sulphur or phosphorus. A model of the mechanism of nitrogen dependent control is presented. Agrobacterium sp. ATCC 31749 grew well on a number of monosaccharides and lactose, moderately well on succinate and poorly on glycerol. Good curdlan production was observed from mannose, glucose and galactose with a reasonable curdlan yield obtained from sucrose. Curdlan yields when lactose, maltose or glycerol were supplied were poor and no curdlan was obtained from culture on succinate. The effects of other physiological conditions were examined. Arsenate inhibited neither initiation nor continuation of curdlan biosynthesis when added to the medium in concentrations up to 10mM. 5mM sodium azide inhibited curdlan production but not glucose uptake. A similar effect was observed when the ionophore tetracaine (1mgml-1) was added to the medium. EDTA inhibited curdlan production and glucose uptake whilst EGTA inhibited neither. Chloramphenicol inhibited curdlan production as did rifampicin. Analysis of the kinetics and degradation products of enzyme hydrolysis revealed a similarity between neutralised gels and gels formed by low temperature heating. Results obtained with native curdlan or curdlan preparations obtained by boiling aqueous suspensions were similar. The implications or these results on curdlan biosynthesis are discussed.
8
Cox, Chasity Marie. "The effects of dietary β-glucan supplementation on performance and immune response of broiler chicks during an Eimeria challenge". Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/46327.
Повний текст джерелаАнотація:
Escalating consumer concerns have placed the poultry industry under mounting pressure to reduce the use of chemotherapeutic agents as feed additives. One possible alternative receiving increased attention is the use of immunomodulators such as β-glucan. A pilot study evaluated the effects of a yeast derived β-glucan (Auxoferm YGT) on growth performance and immune response of broiler chickens. Day-old chicks were fed a diet containing 0, 0.02, or 0.1% yeast β-glucan. On days 7 and 14 post-hatch, body weight and relative immune organ weights were measured, peripheral blood was collected to determine heterophil to lymphocyte (H:L) ratios, and small intestinal sections were sampled to evaluate relative gene expression. The addition of β-glucan had no influence on growth. Dietary β-glucan supplementation modulated the expression of interleukin (IL)-8, IL-18, interferon (IFN)-γ and inducible nitric oxide synthase (iNOS) in the small intestine. A subsequent study was conducted to investigate the effects of dietary β-glucan on broiler chick (1440 birds) performance and immune response during a mixed Eimeria infection (day 8 of age). Measurements were taken and samples collected on days 4, 7, 10, 14 and 21 post-hatch. The results from this study show that β-glucan supplementation did not negatively impact performance. The addition of β-glucan to the diet resulted in reduced gross lesion severity and increased H:L ratios. The gene expression results suggest that β-glucans are capable of skewing the host immune response toward aTh1 mediated response and consequently down-regulating the Th2 mediated response.Master of Science
9
Konishi, Teruko. "THE EXPRESSION OF SUCROSE SYNTHASE AND ITS ROLE IN PLANT β-GLUCAN SYNTHESIS". Kyoto University, 2002. http://hdl.handle.net/2433/149898.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第9606号
農博第1234号
新制||農||841(附属図書館)
学位論文||H14||N3638(農学部図書室)
UT51-2002-G364
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 酒井 富久美, 教授 關谷 次郎, 教授 島田 幹夫
学位規則第4条第1項該当
10
Tada, Toshio. "Structure and Viscoelastic Properties of Microbial β-1, 3-Glucan Solutions and Gels". Kyoto University, 1998. http://hdl.handle.net/2433/182309.
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11
Asare, Shardrack O. "Optimized Acid/Base Extraction and Structural Characterization of β-glucan from Saccharomyces Cerevisiae". Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etd/2513.
Повний текст джерелаАнотація:
β-glucan is a major component of the fungal cell wall consisting of (1→3)-β linked glucose polymers with (1→6)-β linked side chains. The published classical isolation procedure of β-glucan from Saccharomyces cerevisiae is expensive and time-consuming. Thus, the aim of this research was to develop an effective procedure for the extraction of glucans. We have developed a new method for glucan extraction that will be cost effective and will maintain the native structure of the glucan. The method that we developed is 80% faster and utilizes 1/3 of the reagents compared to the published classical method. Further, the method developed increases the yield from 2.9 % to 10.3 %. Our new process has a branching frequency of 18.4 down from 197 and a side chain of 5.1 up from 2.5. The data indicate a more preserved native structure of isolated glucans.
12
Kuhaudomlarp, Sakonwan. "The new families of β-(1→3)-glucan phosphorylases : identification, mechanisms and applications in carbohydrate synthesis". Thesis, University of East Anglia, 2018. https://ueaeprints.uea.ac.uk/68435/.
Повний текст джерелаАнотація:
β-(1→3)-glucans have applications in human food and health supplements, owning to their reported immunomodulatory properties. Enzymatic synthesis of β-(1→3)-glucans are attractive due to stereo- and regio-specificity of the biocatalytic enzymes. Glycoside phosphorylases (GPs) catalyse phosphorolysis of glycan into sugar 1-phosphate and shortened glycan chain, the reaction of which can be reversed for glycan synthesis. In order to apply GPs as biocatalyst of β-(1→3)gluco-oligosaccharide production, this work concentrated on identification of sequences, biochemical characterisation and structural elucidation of GPs acting on β-(1→3)-gluco-oligosaccharides, in order to understand the mechanism underlying the enzyme substrate specificity. A GP from Paenibacillus sp. YM-1 (PsLBP), belonging to glycoside hydrolase (GH) family 94, has been reported for its specificity towards a disaccharide, β-D-glucopyranosyl-(1→3)-D-glucopyranose. In this study, the activity of PsLBP on sugar donors, α-D-mannose 1-phosphate and α-D-glucose 1-phosphate, was investigated. X-ray crystallography and saturation transfer difference NMR were used to investigate the interaction between PsLBP and its donor substrates, and a mechanism underlying the substrate chain length specificity of the enzyme. Two new families, GH149 and GHyyy, were discovered. Two GH149 candidates, a Euglena gracilis phosphorylase 1 and Pro_7066, were characterised to confirm their function as β-(1→3)-glucan phosphorylase acting on disaccharide and longer substrates. A GHyyy from Paenibacillus polymyxa was characterised to confirm its β-(1→3)-glucan phosphorylase activity, albeit with a distinct substrate length specificity from the GH149 enzymes. Multiple alignment of GH94, GH149 and GHyyy proteins identified conserved amino acids located in the enzyme active site, implying a conserved catalytic mechanism. Structural studies of Pro_7066 revealed two additional domains and an oligosaccharide surface binding site, which are unique to GH149 and may contribute to the enzyme preference for long oligosaccharide substrates. Bacterial GH149 or GHyyy genes map to gene clusters containing genes encoding other GHs and membrane transporters, highlighting the involvement of the enzymes in polysaccharide degradation.
13
Nakai, Toru. "Antifungal Characterization of FK463, an Inhibitor of 1,3-β-D-Glucan Synthesis in Fungal Cell Walls". Kyoto University, 2004. http://hdl.handle.net/2433/148347.
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14
Pionnier, Nicolas. "Immunomodulation of the innate response in common carp Cyprinus carpio by β-glucan feeding and pathogenic infection". Thesis, Keele University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.699664.
Повний текст джерелаАнотація:
Two major components of the common carp Cyprinus carpio innate response, i.e. the C-reactive protein (CRP) and the complement system, have been analysed in common carp either orally immunostimulated with β-glucan or infected with a pathogen or both. Immune response was examined at different levels, from serum circulating protein levels or activity to related gene expression in a wide range of immune related tissues such as liver, head kidney, mid-gut, gills and spleen. In addition, recombinant technologies were investigated in order to generate and produce subsequent amounts of carp CRP. Oral administration of β-glucan significantly stimulated carp CRP and complement responses with elevated serum CRP levels and complement activity and up- and down regulation of related genes in immune related tissues from 7 days of treatment. A subsequent intraperitoneal injection of LPS or Poly(I:C) as mimicries of bacterial and virus infection respectively also did have significant effects on the production (gene expression) and the circulation (scrum levels or activities) of these acute phase proteins. In addition, results from a challenge conducted on common carp with Aeromonas salmonicida, the causative agent of furunculosis, have shown that β-glucan enhanced and stimulated carp CRP and complement responses to the bacterial infection. These findings arc of importance in respect to the use of β-glucan as an alternative low cost strategy to the use of vaccines or antibiotics to enhance and stimulate the fish immune system. Innate response was analysed in carp infected with the Koi Herpes Virus (KHV), the etiological agent of a virulent and lethal disease. Results have shown a serum CRP level 10 fold increase and a serum complement activity 5 fold increase in less than 72 hours, revealing that CRP and complement act as acute phase reactants in response to KHV infection in common carp.
15
Björklund, Thea. "Analysis of mixed-linkage (1-3, 1-4)-β-D-glucan in Swedish cereal cultivars and bread". Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-74671.
Повний текст джерелаАнотація:
β-glucans are unavailable carbohydrates and a dietary fiber that cannot be readily metabolized by our own bodies’ enzymes in the gastrointestinal tract. They are instead metabolized by our microbiota in the large intestine, were they have multiple health benefits. They help with keeping the microbiota in balance and regulating our immune system. They have also been shown to have cholesterol lowering effects. β-glucans are found in cereals like barley, oat, rye, and wheat but they can also come from other sources like bacterial cell walls and fungi. However, depending on their origin, they have different structures and properties. β-glucans from cereals are linear polymers of β-(1→4)-D-glycopyranosyl units separated by single units of β-(1→3)-D-glycopyranosyl in a mixed linkage. The concentration of β-glucan is highly varied between cereal type as well as cultivar of the same cereal. The aim of this study was to investigate if there is a difference in β-glucan content between commercial bread baked using traditional versus modern cereal cultivars. β-glucan was determined using the Megazyme assay kit, a method approved by the American association of cereal chemists (AACC) International. The method uses a highly specific enzymatic breakdown of β-glucan into D-glucose that can then be determined colorimetrically. The results for β-glucan showed high variation between different types of cereals and bread tested, were grains like barley and rye had higher β-glucan content compared to oat and wheat, showing clear health benefits to eating grains like barley and rye, over grains like wheat. The β-glucan content for cereals ranged from 0.30 – 3.66% of dry weight, whereas the different bread had β-glucan ranging from 0.31 – 1.14% of dry weight. There was no significant difference between modern versus traditional cultivars and therefore neither had any greater health benefits from a β-glucan content perspective. The daily consumption of β-glucan needed to show cholesterol lowering effects is 3g, which in this study mean that about 7.5 bread slices (about 300 g) of the highest β-glucan containing bread is needed to be eaten daily to achieve the daily intake goal.
16
Yoshida, Tomoki. "Chemical Properties of Corn Pericarp as a Renewable Resource." Kyoto University, 2014. http://hdl.handle.net/2433/188756.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第18318号
農博第2043号
新制||農||1021(附属図書館)
学位論文||H26||N4825(農学部図書室)
31176
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 本田 与一, 教授 星野 敏, 教授 縄田 栄治
学位規則第4条第1項該当
17
Coon, Melissa A. "Characterization and Variable Expression of the CslF6 Homologs in Oat (Avena sp.)." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3750.
Повний текст джерелаАнотація:
(1,3;1,4)-β- D-glucan (β-glucan) is a plant cell wall hemicellulose and a main component of endosperm cell walls. The Cellulose Synthase F family of genes is involved in the synthesis of β-glucan. In this study full-length genomic sequences of CslF6 were obtained from multiple Avena species. Three unique alleles were found in each A. sativa line. Comparisons of these alleles to diploid Avena species allowed for identification of the genomic origin of each allele. The A and D genome alleles had identical amino acid sequences while the C-genome had 13 different amino acids. Global expression of CslF6 was completed at three developmental time point and three tissue types. RNAseq technology was utilized to determine genome specific expression patterns. Differential expression of genome specific-copies of CslF6 was found at all time points tested. Lower levels of C-genome expression of CslF6 were associated with increased levels of B-glucan.
18
Fesel, Philipp [Verfasser], Alga [Gutachter] Zuccaro та Paul [Gutachter] Schulze-Lefert. "Insights into β-glucan biology in mutualistic plant-microbe interactions / Philipp Fesel ; Gutachter: Alga Zuccaro, Paul Schulze-Lefert". Köln : Universitäts- und Stadtbibliothek Köln, 2017. http://d-nb.info/1152004980/34.
Повний текст джерела
19
Mitra, Sabori. "Characterisation of physicochemical properties of different oat cultivars used in noodle processing: effects on quality and β-glucan". Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/562.
Повний текст джерелаАнотація:
Research characterised the physicochemical properties of different oat cultivars used in noodle processing and their effects on noodle quality and β-glucan content. The effect of oat cultivar, season and processing on noodle and β-glucan quality was investigated. This research provided an insight into the quality differences between oat cultivars, effect of season on oat cultivar quality and the oat cultivars most suitable for incorporation into oat-wheat noodles in terms of processing, sensory and nutritional properties.
20
Samar, Danial. "Idenfitication and characterization of Tft1, a glycosyltransferase necessary for cell wall β,3-1,4-Glucan synthesis in Aspergillus fumigatus". Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/3526.
Повний текст джерелаАнотація:
Aspergillus fumigatusis a ubiquitous environmental soil fungus. With recent development and advancement in medical treatments leading to immunosuppression, there has been an increase in incidence in aspergillosis. With the emergence of antifungal resistance isolates and the continued high mortality rate for invasive aspergillosis, the hunt for new antifungal drug targets is critical. Research on A. fumigatus is still in its infancy, partly due to the relatively recent rise of A. fumigatus as a clinically significant pathogen. The cell wall has been demonstrated to be critical for survival of this fungal organism, with interference of cell wall construction leading to cell death or reduced growth. This, coupled with the lack of shared mechanisms in humans, makes targeting cell wall synthesis for antifungal therapy a reasonable possibility.
The cell wall of A. fumigatus shares a few similarities to S. cerevisiae. However, major differences exist, including the presence of β-1,3;1,4-glucan in the cell wall of A. fumigatus. In fact, the presence of β-1,3;1,4-glucan was never previously described in fungi before Latge's group reported it a number of years ago. It comprises about 10% of the glucans in the cell wall of A. fumigatus, but its role in the cell wall is unknown. In 2006 and 2009, two papers were published that demonstrated the role of CslF and CslH(Cellulose like synthases) in the production of β-1,3;1,4-glucan of the cell wall in rice and barley, respectively. Taking both protein sequences for these genes, we blasted it against the A. fumigatus database for any possible orthologues. A single orthologue, albeit with weak homology, was identified that named TFT1. We hypothesize that TFT1a plays a direct role in A. fumigatus β-1,3;1,4-glucan synthesis. Through Agrobacterium tumefaciens mediated transformation, an A. fumigatus strain lacking this enzyme (tft1Δ) was generated. From tft1Δ a revertant strain (revtft1) was created where the gene was reintroduced. Immunofluorescence staining with antibodies against β-1,3;1,4-glucan and biochemical quantification both demonstrated complete loss of β-1,3;1,4-glucan within the cell wall of the tft1Δ strain, with recovery detected in revtft1. This strongly suggests that this enzyme does indeed play a role in β-1,3;1,4-glucan synthesis in A. fumigatus. Growth experiments, spore size determination and an in vitro model of virulence also indicated that the loss of TFT1 leads to additional phenotypes. While the precise mechanism for β-1,3;1,4-glucan synthesis is unknown, the results shown herein indicate a pivotal role forTFT1 in its biosynthesis, and resulting phenotypes upon loss of mixed linkage glucan adds some clues to its role in the cell wall of A. fumigatus.
21
Garcia, Ely O. [Verfasser], Holger N. [Akademischer Betreuer] Deising та Ralf T. [Akademischer Betreuer] Vögele. "Infection structure-specificity of β-1,3-glucan synthase is essential for pathogenicity of Colletotrichum graminicola and evasion of glucan-triggered immunity / Ely O. Garcia. Betreuer: Holger N. Deising ; Ralf T. Vögele". Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2013. http://d-nb.info/1035405628/34.
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Eriksson, Maja. "Soluble β-glucan and heparin as modulators of the immune response elicited by vaccination against a tumor stromal antigen". Thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-230153.
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23
Rao, Harpal. "Stimulus-response coupling in host-pathogen interactions of higher- plants - a study of β-1,3-D-glucan (callose) synthase". Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627585.
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24
Arthur, Clara. "Linkage Analysis and Compositional Studies of β-Glucan from Saccharomyces Cerevisiae and Compositional Studies of Mannan from Candida Albicans". Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etd/2537.
Повний текст джерелаАнотація:
The efficacy of a novel carbohydrate extraction procedure was investigated with methylation analysis and alditol acetate method by Gas Chromatography-Mass Spectrometry. A published extraction procedure for β-glucans was compared to one developed in house. Both procedures gave a dominant glucose peak in the Gas chromatogram indicative of successful β-glucan isolation. Further linkage studies showed four linkage positions for β-glucans isolated with the published method; terminal, 1,3-linkage, 1,6-linkage and 1,3,6-linkage, while β-glucans isolated using the new method showed six linkage positions; terminal, 1,3-linkage, 1,6-linkage, 1,4-linkage, 1,2,3-linkage and 1,3,6-linkage. Diminishing β-glucan linkage peaks in the chromatogram for the published method indicated structure degradation. The results for mannan isolated with 50 mM base gave mannose as a dominant component compared to mannan isolated with 50 mM acid. Base extracted mannan also indicated a good yield of mannan in hyphal form of Candida albicans. This has not been reported with other published isolation methods.
25
Akramienė, Dalia. "Assessment of the modulation of photodynamic effect by β-glucan and characteristics of anti-CD7 monoclonal antibody during tumor process". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110309_111259-65000.
Повний текст джерелаАнотація:
Activation of the immune system during photodynamic therapy (PDT) and improvement of the effector functions of mAbs - these are the ways to use and enhance the potential of the immune system to fight cancer. Tumor cells lack β-glucan as a surface compo¬nent and can‘t trigger complement receptor 3-dependent cellular cytoto¬xicity and initiate tumor-killing activity during PDT. So, it gave rise to the hypothesis that β-glucan in combination with PDT will produce more effective killing of by iC3b fragment opsonized tumor cells. The human Fc portion is essential for the recruiting of human effector immune cells to produce antitumor effect. Therefore, connection of Fv portion of murine anti-CD7 antibody with Fc portion of human IgG1 can be helpful for such protein to obtain ideal feathers. However, each modification of the monoclonal antibody can cause the lost or decrease in the rate of protein expression and antigen-binding properties. Monoclonal antibody products are unique in their molecules. Because of post-translational modifications that often occur during the fermentation process, the final product is heterogeneous. Therefore, careful characterization of monoclonal antibodies is required in order to assess their identity, purity, potency and safety. Response of Lewis lung carcinoma tumor to PDT modulated by β-glucan was assessed in mice and functional characteristics of novel purified chimeric anti-CD7 antibody was tested in this study.Imuninės sistemos aktyvinimas taikant fotosensibilizacinę terapiją (FNT) ir monokloninių antikūnų efektorinių funkcijų gerinimas yra vienas iš būdų, kaip naudoti ir sustiprinti organizmo imuninės sistemos veiksnių potencialą kovai su naviku. Navikinės ląstelės membranos paviršiuje nėra β-gliukano, todėl FNT metu negali būti aktyvinamas nuo komplemento receptoriaus 3 priklausomas ląstelės citotoksiškumo mechanizmas bei sukeliama navikinės ląstelės žūtis. Todėl galima tikėtis, kad β-gliukanas ir FNT, taikomi kartu, gali aktyvinti iC3b frag¬mento opsonizuotų navikinių ląstelių žūtį. Norint aktyvinti žmogaus imunines ląsteles priešnavikiniam poveikiui sukelti, pelės monokloniniam antikūnui būtina žmogaus imunoglobulino Fc dalis. Todėl pelės antikūno prieš CD7 vienos grandinės Fv fragmento sujungimas su žmogaus imunoglobulino G1 Fc dalimi baltymui gali suteikti idealias savybes. Tačiau, bet kokia monokloninio antikūno modifikacija gali keisti jo savybes ir, išskiriant baltymą, dėl daugiapakopio proceso ji gali keistis. Todėl, norint įvertinti chimerinio CD7-Fc antikūno identiškumą, grynumą, veiksmingumą bei saugumą, būtina atlikti tyrimus, kuriais būtų galima nustatyti, ar antikūnas išlaiko specifiškumą antigenui, kaip aktyviai jungiasi prie jo, ar aktyvina imuninius mechanizmus. Šio tyrimo metu buvo vertintas pelėms įskiepytos Luiso plaučių karcinomos atsakas į FNT moduliaciją β-gliukanu ir išgrynintas chimerinis antikūnas prieš CD7 bei ištirtos jo funkcinės savybės in vitro.
26
Sykes, Peter. "The characterisation and management of workers' exposure to dust, endotoxin and β-(1-3) glucan at large-scale composting facilities". Thesis, Cardiff Metropolitan University, 2011. http://hdl.handle.net/10369/3262.
Повний текст джерелаАнотація:
Commercial composting is becoming more prevalent in the UK as biodegradable municipal waste is being diverted from landfill. Exposure to the organisms actively grown during the composting of waste are known to cause adverse effects on respiratory health when these organisms, or fragments of these organisms, become airborne forming a ‘bioaerosol’. The aim of this Thesis is to characterise compost workers’ exposure levels to bioaerosols by measuring their exposure to dust, endotoxin and β-(1-3) glucan and to use this exposure data to inform the development of evidence-based risk assessment and risk mitigation measures. In general, workers’ exposure to dust was low in the four sites studied but there was extensive variation in personal exposure levels. The inhalable fraction was found to be the predominant fraction of concern. Manual sorting and the screening of final product gave rise to high exposures to inhalable dust on occasion. Despite dust levels being generally low, workers’ exposures to endotoxin and to a lesser extent β-(1-3) glucan were elevated and workers were exposed to levels thought to be related to respiratory symptoms and disease. Any activities involving the movement of waste resulted in elevated levels of endotoxin and β-(1-3) glucan at all four sites investigated in this study. Vehicle operators’ exposure levels were high and a multi-faceted strategy is needed to reduce exposure levels to an acceptable level. Currently, no Workplace Exposure Limits or agreed dose-response estimates exist in the UK to manage workers’ exposure levels. Consequently the risk to worker’s health is difficult to characterise. The COSHH Regulations require employers to reduce compost workers’ exposure levels to bioaerosols ‘so far as is reasonably practical’. This study discusses the need for site-specific, task-specific risk assessments to be conducted and that robust risk mitigation measures are required to minimise the impact on compost workers health.
27
Matsumura, Yasufumi. "Quantitative real-time PCR and the (1→3)-β-D-glucan assay for differentiation between Pneumocystis jirovecii pneumonia and colonization". Kyoto University, 2012. http://hdl.handle.net/2433/157439.
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28
Salimi, Khorshidi Ali. "Use of ultrasound to determine the effects of sheeting work input and barley β-glucan addition on mechanical properties of Asian wheat noodles". Journal of Texture Studies, 2014. http://hdl.handle.net/1993/31962.
Повний текст джерелаАнотація:
Empirical tests developed for an objective evaluation of noodle texture as well as sensory methods provide no information about the rheological parameters responsible for differences in the texture of Asian noodles. Therefore, there is a need for a technique to evaluate the rheological properties of Asian noodles that is fast, easy and inexpensive. Promising results from ultrasonic assessments of the rheological properties of wheat flour doughs and preliminary noodle studies were an encouragement to use ultrasound to address such need in this thesis.
Using ultrasound at a relatively high frequency (1.4 MHz), the rheological properties of raw noodles made with three Canadian wheat varieties at various barley β-glucan (BBG) contents, sheeting work input levels and salt to kansui ratios (formulas) were evaluated. Conventional rheological, i.e., stress relaxation (SR) and uniaxial extension (Kieffer), measurements were employed for comparison purposes. The capability of ultrasound for evaluating the effects of BBG addition and sheeting work input on the rheological properties of raw wheat noodles of this study was confirmed. A greater sensitivity of ultrasound to microscopic changes in noodle dough structure, compared to SR and Kieffer tests, was reflected in differences between the results of ultrasound and those of the SR and Kieffer tests with respect to the influences of flour variety and formula on noodle rheology. Investigations of the density of raw noodles showed that air bubbles were present in the noodle dough matrix.
A simple, fast and low-cost method, based on the measurement of noodle dough dimensions during the sheeting process, was proposed for a quick evaluation of noodle dough rheology. The results of the proposed method were in agreement with those of conventional rheological measurements on the effects of flour variety and sheeting work input on noodle texture. The time-dependent effect of kansui on noodle dough structure was confirmed by comparing the results of this new method with those of SR and Kieffer tests with respect to the effect of formula on noodle rheology. Further investigations are proposed to establish this method for quick assessment of Asian wheat noodle rheology.February 2017
29
Cleary, Louise Jane. "The potential use of (1→3, 1→4)-β-D-glucan from barley as a functional food ingredient for cereal foods". Thesis, University of Plymouth, 2006. http://hdl.handle.net/10026.1/2525.
Повний текст джерелаАнотація:
The health related importance of dietary fibre as part of a balanced diet is well known. More recently, soluble fibres, such as (1→3, 1→4)-β-D-glucan (β-glucan), have been shown to influence glycaemic, insulin and cholesterol responses to foods. Barley is a rich source of β-glucan; however, consumption of products containing barley grain or flour is often limited by their negative organoleptic quality. A potential solution lies in the use of barley as an extraction source for β-glucan fractions. One problem with regards to this is the lack of clarity on the use of barley β-glucan fractions in food systems, particularly their physiological and physico-chemical properties. The aim of this study was to determine the potential of barley β-glucan fractions as functional ingredients in cereal foods. The effects of extraction treatment on fraction composition and physico-chemical properties were investigated. Subsequently, barley β-glucan fractions (from a bench-top and commercial extraction procedure and of differing molecular weight) were incorporated into white wheat bread and durum wheat semolina pasta. The effects on product quality and in vitro starch digestibility were investigated. Simultaneously, the effect of processing on the degradation of β-glucan molecular weight was evaluated. Different extraction treatments may influence the composition and physico-chemical properties of barley β-glucan fractions. The inclusion of barley β-glucan fractions in bread and pasta resulted in a slight reduction of product quality but generally reduced the rate and extent of in vitro starch digestibility. Factors such as composition, water retention capacity, integration within the cereal food matrix and molecular weight may influence the behaviour of the fractions. Bread manufacture resulted in degradation of β-glucan molecular weight, although only high molecular weight β-glucans were susceptible to degradation. The results of the study have both scientific and commercial value and provide foundations for further development of barley β-glucan enriched cereal products.
30
Kühlwein, Holger. "Effect of dietary β-glucan supplementation on growth, intestinal functionality and disease progression in selected cyprinids (Cyprinus carpio and Danio rerio)". Thesis, University of Plymouth, 2014. http://hdl.handle.net/10026.1/2873.
Повний текст джерелаАнотація:
Three experiments were conducted to investigate the effects of dietary supplementation of a ß-(1,3)(1,6)-D-glucan derived from the yeast Saccharomyces cerevisiae, on growth performance parameters and intestinal functionality in mirror carp (Cyprinus carpio L.) and on progression of a chronic, pre-existing mycobacteriosis in zebrafish (Danio rerio). The 1st experiment revealed that mirror carp fed diets containing 1% and 2% ß-glucan showed significant improvements in growth performance compared to fish fed both the control and the 0.1% ß-glucan containing diet. Equally, fish fed diets supplemented with 1% and 2% ß-glucan displayed significantly higher infiltration of leukocytes into the epithelial layer of in the anterior intestine. This effect was not observed in the posterior intestine. There were no significant differences in the intestinal absorptive surface area and number of goblet cells in either intestinal region. Compared to control fed fish, the haematocrit value was significantly elevated in fish fed the 2% ß-glucan diet. The blood monocyte fraction was significantly higher in fish fed the 1% and 2% ß-glucan diets. No significant changes were observed in the other blood parameters assessed. In the 2nd experiment, culture-dependent microbiology unveiled that aerobic heterotrophic bacterial levels in mirror carp intestinal microbiota were unaffected by dietary β-glucan after two and four weeks. No effects were observed on the allochthonous lactic acid bacteria (LAB) populations at either time point, however, reduced autochthonous LAB populations were observed at week four. PCR-DGGE confirmed these findings through a reduction of the abundance of autochthonous LAB operational taxonomical units (OTUs) in β-glucan fed fish compared to the control fed fish. DGGE analyses also revealed that dietary β-glucan reduced the number of OTUs and the species richness of the allochthonous microbiota after two weeks, but not after four weeks. In contrast, dietary β-glucan reduced the number of OTUs, the species richness and diversity of the autochthonous microbiota after two weeks, and those parameters remained reduced after four weeks. Intestinal microvilli length and density were significantly increased after four weeks in fish fed diets supplemented with 1% β-glucan. The 3rd experiment comprised of two individual trials where dead or moribund fish displayed the classical clinical signs of mycobacteriosis. In experiment I (200 days), zebrafish were fed diets supplemented with 0% (control, C) or 0.1% ß-glucan (B). In experiment II (63 days), zebrafish were fed diet C or diet B continuously or both diets intermittently (CB) in weekly intervals. Dietary ß-glucan failed to improve survival rates in both experiments. In experiment II, histopathological analysis revealed absent (normal appearance), moderate and severe manifestations of granulomas. Ecological microbial community analysis of intestinal samples collected at day 63 showed significantly higher number of OTUs, species richness and diversity in treatments B and CB compared to the control treatment. In conclusion, high dietary ß-glucan supplementation levels enhanced growth performance, leukocyte infiltration in the anterior intestine and the ultrastructure of the enterocytes in mirror carp without detrimental effects on intestinal morphology or the haemato-immunological parameters assessed. In addition, intestinal microbial communities were altered in healthy mirror carp and diseased zebrafish. It was also demonstrated that dietary ß-glucan failed to impact the progression of a pre-existing mycobacteriosis in zebrafish. Future research is required to investigate the underlying reasons for the observed effects by applying advanced molecular techniques, and whether these effects occur under commercial husbandry, or in different fish species.
31
Kimura, Takashi. "Studies on pharmacological activities of the cauliflower mushroom Sparassis crispa." Kyoto University, 2013. http://hdl.handle.net/2433/180630.
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32
Tu, Fei. "Roles of Endothelial Cell Heat Shock Protein A12B and β-glucan, a reagent for trained Immunity in the Regulation of Inflammation in Sepsis". Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3792.
Повний текст джерелаАнотація:
Sepsis is dysregulated host immune response to infection causing life-threatening organ dysfunction. Endothelial cell dysfunction and uncontrolled inflammatory responses are two contributors for sepsis-induced mortality. The crosstalk between endothelial and immune cells plays a critical role in the pathophysiology of sepsis. Therefore, understanding the mechanism of interaction between endothelial and immune cells will provide novel information to develop therapeutic strategies for sepsis.
Pathogen associated moleculear patterns (PAMPs) and/or damage associated molecular patterns (DAMPs) produced during sepsis, activate endothelial cells to increase the expression of adhesion molecules, attracting immune cell infiltration into the tissues. Uncontrolled inflammatory responses during the early phase of sepsis contribute to organ failure and lethality. Over 100 clinical trials, targeting inflammatory responses in sepsis, have failed in the past three decades. Thereby, developing novel therapeutic strategies for sepsis are urgent.
Heat shock protein A12B (HSPA12B), as one member of HSP70 family, predominately expressed in the endothelial cells, plays important roles in many pathophysiological processes. Currently, we observed endothelial cell specific HSPA12B deficiency (HSPA12B-/-) exacerbates mortality in sepsis induced by cecal ligation puncture (CLP). HSPA12B-/- septic mice exhibits increased expressions of adhesion molecule and infiltrated macrophages in the myocardium and activated macrophages in the peritoneal cavity. In vitro studies show that HSPA12B could be secreted from endothelial cells via exosome. HSPA12B carried by exosomes can be uptaken by macrophages to downregulate macrophage NF-kB activation and pro-inflammatory cytokine production.
Trained immunity, induced by β-glucan, causes immune memory in innate immune cells, with an altered response towards another challenge. We have found that mice received β-glucan seven days before CLP sepsis exhibit attenuated mortality with decreased pro-inflammatory responses. We found that β-glucan significantly increased the levels of HSPA12B in endothelial cells and endothelial exosomes. β-glucan induced endothelial exosomes markedly suppress macrophage NF-kB activation and pro-inflammatory responses.
The current data suggests that HSPA12B plays a novel role in the regulation of immune and inflammatory responses and that HSPA12B could be an important mediator for the crosstalk between endothelial cells and macrophages during sepsis. β-glucan regulates endothelial cell functions and immune/inflammatory responses, thus improving survival outcome in CLP sepsis.
33
Tu, Fei. "Roles of Endothelial Cell Heat Shock Protein A12B and β-glucan, a reagent for trained Immunity in the Regulation of Inflammation in Sepsis". Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etd/3792.
Повний текст джерелаАнотація:
Sepsis is dysregulated host immune response to infection causing life-threatening organ dysfunction. Endothelial cell dysfunction and uncontrolled inflammatory responses are two contributors for sepsis-induced mortality. The crosstalk between endothelial and immune cells plays a critical role in the pathophysiology of sepsis. Therefore, understanding the mechanism of interaction between endothelial and immune cells will provide novel information to develop therapeutic strategies for sepsis.
Pathogen associated moleculear patterns (PAMPs) and/or damage associated molecular patterns (DAMPs) produced during sepsis, activate endothelial cells to increase the expression of adhesion molecules, attracting immune cell infiltration into the tissues. Uncontrolled inflammatory responses during the early phase of sepsis contribute to organ failure and lethality. Over 100 clinical trials, targeting inflammatory responses in sepsis, have failed in the past three decades. Thereby, developing novel therapeutic strategies for sepsis are urgent.
Heat shock protein A12B (HSPA12B), as one member of HSP70 family, predominately expressed in the endothelial cells, plays important roles in many pathophysiological processes. Currently, we observed endothelial cell specific HSPA12B deficiency (HSPA12B-/-) exacerbates mortality in sepsis induced by cecal ligation puncture (CLP). HSPA12B-/- septic mice exhibits increased expressions of adhesion molecule and infiltrated macrophages in the myocardium and activated macrophages in the peritoneal cavity. In vitro studies show that HSPA12B could be secreted from endothelial cells via exosome. HSPA12B carried by exosomes can be uptaken by macrophages to downregulate macrophage NF-kB activation and pro-inflammatory cytokine production.
Trained immunity, induced by β-glucan, causes immune memory in innate immune cells, with an altered response towards another challenge. We have found that mice received β-glucan seven days before CLP sepsis exhibit attenuated mortality with decreased pro-inflammatory responses. We found that β-glucan significantly increased the levels of HSPA12B in endothelial cells and endothelial exosomes. β-glucan induced endothelial exosomes markedly suppress macrophage NF-kB activation and pro-inflammatory responses.
The current data suggests that HSPA12B plays a novel role in the regulation of immune and inflammatory responses and that HSPA12B could be an important mediator for the crosstalk between endothelial cells and macrophages during sepsis. β-glucan regulates endothelial cell functions and immune/inflammatory responses, thus improving survival outcome in CLP sepsis.
34
Goulart, Fernanda Rodrigues. "Potencial prebiótico de diferentes concentrados de fibra alimentar na dieta de juvenis de jundiá (Rhamdia quelen)." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/4364.
Повний текст джерелаАнотація:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe traditional use of antibiotics in aquaculture as growth promoters has been limited due to the negative effects caused by these drugs. As an alternative to the use of these drugs has been sought manipulation of the microbiota of the gastrointestinal tract of aquatic animals through the use of oligosaccharides and dietary fibers with prebiotic potential. Thus, this study aimed to apply different methodologies to obtain Dietary Fiber Concentrates (DFC) = mucilage (MG); pectin (PN) and β-glucan + manan (βG + M) and evaluate the prebiotic potential of these supplements in the diet of juvenile jundiá (Rhamdia quelen). The determination of the nutritional composition of the ingredients revealed that the predominant component in all DFCs were dietary fiber and insoluble fiber. The DFC that had higher extraction yield was βG + M (19.81 ± 8.54%), followed by pectin (14.54% ± 2.72), and mucilage (7.18 ± 1.54%). The composition of mucilage and pectin had a greater diversity of monosaccharides, since the βG+M consisted primarily of mannose (74.5%) and glucose (24.3%). The supplementation of DFC in jundiás diet was assessed for eight weeks through study of growth, body nutrient deposition, digestive enzymes, biochemical and metabolic parameters, responses to stress and immune and intestinal morphology. The jundiás supplemented with DFCs achieved higher growth than the control group and similar to animals supplemented with 5 g kg-1 commercial prebiotic (CP 5). Most somatic parameters and whole fish proximate composition were influenced by supplementation of DFCs. The supplementation of pectin promoted lower activity of digestive enzymes in relation the control group. The animals supplemented with DFC obtained positive changes in biochemical parameters. Furthermore, jundiás showed no response to application of the stressor, maintaining basal cortisol levels. The fish supplemented with DFCs had higher hepatic glycogen stores in relation the control group. Moreover, supplementation with DFCs increased the height of intestinal villi of jundiá. However, these values were lower for the animals of the group PC 5. For thickness of the epithelium this variable was higher in the control group compared to animals supplemented with β-glucan+Manana.
O uso tradicional de antibióticos na aquicultura como promotores de crescimento tem sido limitado em função dos efeitos negativos promovidos por estes medicamentos. Como alternativa ao uso destas drogas, tem se buscado a manipulação da microbiota do trato gastrointestinal dos animais aquáticos através da utilização de oligossacarídeos e de fibras alimentares com potencial prebiótico. Neste sentido, este estudo teve como objetivo aplicar metodologias para obtenção de diferentes Concentrados de Fibras Alimentares (CFAs) = Mucilagem (MG); Pectina (PN) e β-Glicana+Mananas (βG+M) e avaliar o potencial prebiótico destes suplementos na dieta de juvenis de jundiá (Rhamdia quelen). A determinação da composição nutricional dos ingredientes revelou que os componentes predominantes em todos os CFAs obtidos foram fibra alimentar total e fibra insolúvel. O CFA que apresentou maior rentabilidade de extração foi a βG+M (19,81%±8,54), seguida da Pectina (14,54%±2,72) e Mucilagem (7,18%±1,54). A composição da Mucilagem e Pectina obtiveram maior diversidade de monossacarídeos, já a βG+M consistiu basicamente de manose (74,5%) e glicose (24,3%). A suplementação dos CFAs na dieta de jundiás foi avaliada durante oito semanas, através de estudo de crescimento, deposição corporal de nutrientes, enzimas digestivas, parâmetros bioquímicos e metabólicos, resposta ao estresse e imunológica e morfometria intestinal. Os jundiás suplementados com os CFAs obtiveram crescimento superior em relação ao grupo controle e similar aos animais suplementados com 5 g kg-1 de prebiótico comercial (PC 5). A maioria dos parâmetros somáticos e de composição centesimal de peixe inteiro foram influenciados pela suplementação dos CFAs. A suplementação de Pectina promoveu menor atividade das enzimas digestivas em relação ao grupo controle. Os animais suplementados com os CFAs obtiveram alterações positivas nos parâmetros bioquímicos avaliados. Além disso, os jundiás não mostraram resposta à aplicação do agente estressor, mantendo os níveis de cortisol basal. Os peixes suplementados com os CFAs obtiveram maiores estoques de glicogênio hepático em relação ao grupo controle. Além do mais, a suplementação com os CFAs promoveu aumento na altura de vilos intestinais dos jundiás. Porém, estes valores foram menores em relação aos animais do grupo PC 5. Para espessura do epitélio (EE) esta variável foi maior no grupo Controle comparado aos animais suplementados com β- glicana + Manana.
35
Cowger, Ashlin Elaine. "Bioaerosols Associated with Evaporative Cooler Use in Low-Income Homes in Semi-Arid Climates." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8571.
Повний текст джерелаАнотація:
Asthma is the leading chronic illness in children in the United States. Since children in the U.S. spend a majority of their time indoors there is an increased need to understand key sources of daily asthma triggers in the home. Bacterial endotoxin, dust mite allergens and β-D-glucan have been shown to be potent inducers of asthma attacks, and high levels of these allergens in homes can trigger attacks in those with asthma. We aim to better understand the risks to those with asthma that might be associated with evaporative cooler (EC) use in low-income homes. ECs are often promoted because of their low energy consumption and decreased environmental impact compared to central air conditioning (AC). Because of their lower cost, ECs are more widely used in low-income homes. ECs use evaporation to cool the air, which leads to higher indoor relative humidity. This may create an ecological niche for house dust mites in semi-arid climates where they are normally absent. EC sump water also provides an ideal environment for bacteria and fungi to grow, possibly resulting in EC loading the air with more potential asthma triggers than central air conditioning. We sampled low-income homes around Utah county with central air and evaporative cooling and tested them for the presence of dust mite allergens, β-D-glucan and endotoxin. There were significantly higher levels of endotoxins and β-(1→3)-D-glucans in the EC homes compared to the AC homes, with increased odds of dust mite allergen prevalence but not at clinically significant levels. These findings suggest that in semi-arid environments, endotoxin and β-(1→3)-D-glucan levels in homes with evaporative coolers are more elevated than dust mite allergens.
36
Mello, Mariana Maluli Marinho de [UNESP]. "Uso do beta glucano e avaliação de indicadores de estresse e do sistema imune inato de pacus após manejo de transporte." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143811.
Повний текст джерелаАнотація:
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Manejos inerentes da piscicultura intensiva, como o transporte, desencadeiam resposta de estresse nos animais, podendo causar perdas na produtividade. Como alternativa, o β-glucano, um polissacarídeo derivado da parede celular de cereais, bactérias e fungos, vem sendo muito utilizado na aquicultura pelo seu efeito imunoestimulante. Há evidências de que o β-glucano minimiza os efeitos negativos do estresse por atuar no sistema imune, porém é pouco investigado o seu efeito direto sobre a resposta clássica de estresse. Neste contexto, o presente estudo avaliou, em juvenis de pacu, o uso oral de 0.1% de duas gerações de β-glucano, de diferentes graus de pureza e processamentos, na resposta de estresse e no sistema imune inato, após transporte e inoculação com Aeromonas hydrophila. Avaliamos a concentração de cortisol e glicose plasmáticos como indicadores da resposta de estresse, a atividade respiratória de leucócitos, a atividade hemolítica do sistema complemento, a atividade de lisozima e contagem total e diferencial de leucócitos, como indicadores do sistema imune inato, e o hematócrito, número de eritrócitos, concentração de hemoglobina e volume corpuscular médio de eritrócitos como indicadores hematológicos. As duas gerações de β-glucano utilizadas modularam os níveis de cortisol circulantes, mantendo os níveis elevados até 24 horas após o transporte, sem alteração após o desafio bacteriano. O β-glucano aumentou a atividade hemolítica do sistema complemento e de lisozima após o manejo e após a inoculação bacteriana, e manteve a população de leucócitos circulantes após recuperação de leucopenia, evidenciando o efeito imunoestimulante. A análise geral dos resultados deste estudo sugere o fortalecimento da resposta imune de juvenis de pacu alimentados por 15 dias antes de manejo estressante, com ração contendo 0.1% β-glucano derivado da parede celular de levedura (Sacaromyces cerevisiae).
Inherent handling in intensive fish farming, such as transport, trigger stress response in animals, and may cause losses in productivity. As an alternative, the β-glucan, a polysaccharide derived from the cell walls of cereals, bacteria and fungi, has been widely used in aquaculture due their immunostimulatory effect. The β-glucan minimizes the negative effects of stress by acting on the immune system, but it is little investigated its direct effect on the classical stress response. In this context, the present study evaluated in pacu, the oral administration of 0.1% of two generations of β-glucan, with different degrees of purity and processing methods, on the stress and innate immune system responses, after transport and inoculation with Aeromonas hydrophila. We evaluated the plasma concentration of cortisol and glucose, as stress response indicators, the respiratory activity of leukocytes, the hemolytic activity of the complement system, lysozyme activity and total and differential counts of leukocytes as innate immune system indicators, and hematocrit, number of erythrocytes, hemoglobin concentration, and mean corpuscular volume of erythrocytes as hematological indicators. The two generations of β-glucan modulated the circulating levels of cortisol, keeping the high levels 24 hours after transportation, without changes after the bacterial challenge. The β-glucan increased the hemolytic activity of the complement system and lysozyme after handling and after bacterial inoculation, and kept the population of circulating leukocytes after recovery of leukopenia, demonstrating the immunostimulatory effect. The general results of this study suggest the strengthening of the immune response of pacu juveniles fed for 15 with feed containing 0,1% β-glucan derived from yeast cell wall (Sacaromyces cerevisiae) days before stressful handling.
CNPq: 138990/2014-0
37
Fogarty, Melissa Coon. "Characterization of Hemicellulose Biosynthesis Genes in Avena." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8978.
Повний текст джерелаАнотація:
Avena sativa L. (2n = 6x = 42, AACCDD genome composition) or common oat is the cereal grain possessing the highest levels of water-soluble seed (1-3,1-4)-β-D-glucan (β-glucan), a hemicellulose important to human health due to its ability to lower serum LDL cholesterol levels. Understanding the mechanisms of β-glucan accumulation in oat endosperm is, consequently, of great interest. We report a genome-wide association study (GWAS) to identify quantitative trait loci (QTLs) controlling β-glucan production in oat, identifying 58 significantly associated markers. Synteny with the barley (Hordeum vulgare L.) genome identified four major regions of interest, the CslF and CslH gene families along with UGPase and AGPase as candidate genes. Subgenome-specific expression of the A, C, and D homoeologs of major β-glucan synthase AsCslF6 revealed that AsCslF6_C is the least expressed in all tissue types and time points, with low-β-glucan varieties recording the highest proportion of AsCslF6_C expression. In order to further investigate the candidate genes identified in our GWAS study and gain a greater understanding of the other cell wall polysaccharides that comprise the total fiber content in oat we sought to characterize five additional genes. Accordingly, we cloned and sequenced the three homoeologs of AsUGP and AsAGPS1. AsAGPS1 is the small subunit 1 gene of the enzyme ADP-glucose pyrophosphorylase (AGPase), which is responsible for catalyzing the first committed step in the starch biosynthesis pathway through the production of ADP-glucose. AsUGP is the gene the codes for UDP-glucose pyrophosphorylase (UGPase) an enzyme responsible for the reversible production of UDP-glucose (UDPG). UDPG is used directly or indirectly as a precursor for the biosynthesis of cell wall polysaccharides. In high β-glucan mutant line ‘OT3044’ we observed increased expression of AsUGP with a corresponding reduction of AsAGPS1 expression. Similarly, we observed an inverse expression pattern in low-fiber mutant line ‘OT3018’, wherein AsUGP expression was decreased in favor of AsAGPS1 expression. Further, we also found evidence that these changes in both AsUGP and AsAGPS1 expression are due primarily to up- or down-regulation in the A-genome homoeoalleles. Additionally, we characterized genes in the CslC family (CslC4, CslC9) and CslA family (CslA7) responsible for xyloglucan and glucomannan synthesis, respectively. High-fiber line ‘HiFi’ showed the least amount of overall expression of these three genes, raising the possibility that the increased β-glucan is due to a reduction in other hemicelluloses. After analyzing homoeolog-specific expression in multiple genes we observed that the A genome consistently had the most highly expressed homoeoallele, hinting at a universal preference for expression of this subgenome. We present hypotheses regarding multiple points in carbohydrate metabolism having the potential to alter β-glucan content in oat.
38
Dimitroff, George. "Investigating the synthesis and regulation of (1,3;1,4)-β-glucan biosynthesis". Thesis, 2016. http://hdl.handle.net/2440/112001.
Повний текст джерелаАнотація:
Cereals such as rice (Oryza sativa (Os)), barley (Hordeum vulgare (Hv)) and sorghum (Sorghum bicolor (Sb)) provide a considerable portion of our daily energy requirements. Their cell wall constituents, such as (1,3;1,4)-β-glucan, survive relatively intact through much of the upper human digestive system to reach the colon, where they are fermented by a range of commensal microorganisms. The products of this fermentation help reduce blood cholesterol levels and ameliorate diseases including coronary heart disease, type II diabetes and colorectal cancer. Efforts have therefore been directed toward understanding the regulation and mechanism of (1,3;1,4)-β-glucan biosynthesis to enhance the human health potential and industrial utility of cereal grain. Numerous reports suggest that the CELLULOSE SYNTHASE-LIKE F6 (CslF6) gene encodes the synthase responsible for producing the majority of (1,3;1,4)-β-glucan in cereals. These synthase genes contain species-specific polymorphisms that have been shown to influence the amount and structure of (1,3;1,4)-β-glucan produced when they are expressed heterologously in Nicotiana benthamiana and barley grain. Here, a chimeric approach exchanged sections of the barley (Hv) and sorghum (Sb) CSLF6 synthases to identify regions influencing (1,3;1,4)-β-glucan production and structure. Using this approach an 80 amino acid stretch, which contains the conserved TED and QxxRW motifs, was shown to be responsible for much of the difference in (1,3;1,4)-β-glucan production and structure between the barley and sorghum synthases. Of the six amino acid polymorphisms contained within this section, one affected polysaccharide structure whilst another dictated the amount of (1,3;1,4)-β-glucan. Co-expression in N. benthamiana was used to investigate CSLF6 modulation and complex formation. Results from a variety of chimeric, truncated and mutated constructs suggest that a highly variable section of unknown function, termed the class-specific region (CSR), and the NH2-terminal region of CSLF6 are separately able to mediate complex formation and increase (1,3;1,4)-β-glucan production. Expression of a construct missing the CSR indicated that the region was not structurally or functionally required for (1,3;1,4)-β-glucan synthesis in N. benthamiana. A PilZ domain responsible for cofactor binding and cellulose synthase activation in bacteria was also identified at the COOH-terminal end of the NH2-terminal region of CSLF6, and was shown to influence (1,3;1,4)-β-glucan production. Overall, the results presented here have furthered our understanding of the action of the CSLF6 isoform of the (1,3;1,4)-β-glucan synthase enzyme. This brings us closer to having the capacity to precisely control the synthase’s function, and allowing the prospect of manipulating cereal tissues to contain the optimal amount of (1,3;1,4)-β-glucan with a defined structure for specific human health and industrial applications.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2016.
39
Hakachite, Christopher. "[EMBARGOED] Analysis of cereal cyst nematode resistance mechanisms in barley." Thesis, 2018. http://hdl.handle.net/2440/120235.
Повний текст джерелаАнотація:
Barley (Hordeum vulgare) is a widely grown, valuable cereal crop that is affected by various pests including nematodes. The cereal cyst nematode (CCN) Heterodera avenae is the most widely distributed and damaging species of nematodes to cereal crops grown in temperate regions, including Australia, and is estimated to cause global annual losses of around $160 billion. The use of cultivars resistant to H. avenae is the preferred approach for nematode management and four resistance loci, Rha1, Rha2, Rha3 and Rha4, have been mapped. The Rha4 locus was mapped in the Galleon/Haruna Nijo population to chromosome 5H and since Rha2 and Rha4 provide the most effective resistance against the Australian H. avenae pathotype Ha13 they have been widely used in barley breeding. Despite CCN resistance loci having been mapped in barley and other cereals, no resistance genes have been isolated and characterized. Recently both Rha2 and Rha4 have been fine-mapped and near-diagnostic markers have been developed to provide simple tools for selection. Fine-mapping indicates that approximately 105 genes are linked to the Rha4 locus, including cell wall-related genes predicted to encode (1-4)-β-xylan endohydrolases, also known as xylanases. This thesis reports on experiments that were undertaken to better understand the resistance conferred by Rha4 and to investigate the functions of the xylanases as prime candidate genes. The xylanase genes at the Rha4 locus were cloned and analysed for allelic differences between sequences from the cultivars Sloop (susceptible) and Flagship (Rha4-resistant). Although genes X1 and X2 have been characterised, the X3 gene has not been well described previously. The genomic sequences were used in reciprocal transformation experiments where, under the control of the 35S promoter, the genes from Sloop were transformed into a Flagship background, and vice versa. Tube tests were used to investigate any changes in nematode infection responses, and therefore resistance status, but no significant alterations were detected. However, overexpression of the xylanase genes proved to be detrimental to the overall health of the plant. The xylanases were concomitantly heterologously expressed in Escherichia coli and the X2 protein was characterized in terms of substrate preference and catalytic rate. In more general approaches not directly linked to Rha4 genotype, the natural variation in root polysaccharide amount and distribution, with a focus on (1,3;1,4)-β-glucan and arabinoxylan, was surveyed in a selection of susceptible and resistant barley cultivars. The effect of changes in amount of (1,3;1,4)-β-glucan was also examined through infection of the betaglucanless mutant and transgenic lines carrying either the overexpressed or silenced (1,3;1,4)-β-glucan synthase CslF6 gene. Variable amounts of (1,3;1,4)-β-glucan did not correlate to rates of nematode infection and no clear patterns of polysaccharide profiles could be linked to susceptible or resistant cultivar status. Finally, RNA sequencing was used to profile transcript changes in nematode infected and control Sloop and Flagship roots up to 24 days post inoculation. The patterns of the 105 genes linked to the Rha4 locus were extracted and a set of 27 genes which showed significant fold changes across the time course were profiled. Of these, three strong candidate genes were selected which are differentially expressed in the two cultivars and are involved in biochemical pathways that are feasibly linked to resistance mechanisms. Their putative roles in conferring resistance and how this might be tested were discussed.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food & Wine, 2019
40
Shiu, Hui-Jiun, та 許慧君. "Immunomodulatory Activities of β-Glucan". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/35710491808120889811.
Повний текст джерелаАнотація:
碩士國立屏東科技大學
生物科技研究所
98
β-glucans are abundant in the cell wall of plants, fungi and bacteria, and have been defined as one of the pathogen-associated molecular patterns (PAMPs). Dectin-1 has been known to be the major receptor, alone or cooperating with Toll-like receptors (TLRs) for recognition of β-glucans. The binding between β-glucan and its receptor induces the signal transduction and then affects the immune function. β-glucans binding with dectin-1 can stimulate the activation of phagocytosis, reactive oxygen species (ROS) production, and induction of inflammatory cytokines. In this study, SPF mice were used for evaluating the immunomodulatory activities of a particulate β-Glucan (P-β-glucan). The commercial P-β-glucan, Zymosan and Laminarin, were used as positive controls, whereas Pullulan was used as a negative control. Spleen cells and intestinal epithelial cells taken from the animals 7 days after treatment were used for assessment of the expressions of CD16/32 and Dectin-1. The intracellular signaling associated proteins of Syk and MyD88 were analysized using Western blotting. The results show that both P-β-glucan and Zymosan can induce activation of NF-κB by phosphorylating Syk and MyD88, enhance expressions of Dectin-1 in CD16/32 positive cells, increase the mRNA expressions of Dectin-1 and TLR-2 in spleen cells. Thus, P-β-glucan may modulate the functions of immune cells.
41
Wong, Sie-Chuong. "Regulation of (1,3;1,4)-beta-glucan synthesis in barley (Hordeum vulgare L.) endosperm and leaf tissues." Thesis, 2015. http://hdl.handle.net/2440/93906.
Повний текст джерелаАнотація:
This project was carried out to explore the regulatory mechanism for (1,3;1,4)-β-glucan synthesis in barley (Hordeum vulgare L.) in both endosperm and leaf tissues. For the grain (1,3;1,4)-β-glucan content regulation study, transcriptional profiles of candidate genes involved in (1,3;1,4)-β-glucan synthesis and degradation, from the developing barley endosperm, were compared across parental lines that had been previously used for grain (1,3;1,4)-β-glucan QTL studies. Correspondence between differences in transcript levels of selected genes and the QTL detected in parental lines was analysed. In the high (1,3;1,4)-β-glucan parent of a mapping population with a grain (1,3;1,4)-β-glucan QTL near/at the location of the HvCslF6 gene, HvCSLF6 transcript levels increased sharply late in endosperm development. In contrast, HvCslF6 transcript levels did not differ between parents of a mapping population in which no grain (1,3;1,4)-β-glucan QTL had been mapped near/at the HvCslF6 gene. Co-transcription of a β-glucan exo-glucanase gene, HvExoIV gene with HvCslF9 early in endosperm development and with HvCslF6 late in endosperm development indicated that HvEXOIV could be involved in (1,3;1,4)-β-glucan synthesis. It has been reported that leaf (1,3;1,4)-β-glucan is degraded when plants are incubated in the dark for prolonged periods and is re-synthesized upon re-exposure to a normal day/night cycle. Thus, to investigate the regulation of leaf (1,3;1,4)-β-glucan, the transcript levels of (1,3;1,4)-β-glucan synthase genes and related genes were profiled during (1,3;1,4)-β-glucan mobilization upon dark incubation. Some of the genes that responded to prolonged dark incubation showed diurnal transcription patterns, even in continuous darkness. Among the (1,3;1,4)-β-glucan synthase candidate genes, only HvCslH1 was up-regulated upon dark incubation. Its transcripts quickly returned to control levels upon re-exposure to the normal day/night cycle. None of the (1,3;1,4)-β-glucan synthase genes were up-regulated upon re- exposure to normal day/night cycles. Consistent with what was observed for HvExoIV, HvCslF6 and HvCslF9 in developing endosperm, HvExoIV seemed to exhibit co-transcription gene with the HvCslH1.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2015
42
Ermawar, Riksfardini Annisa. "Metabolic engineering of C₄ grasses for biofuel applications." Thesis, 2016. http://hdl.handle.net/2440/103492.
Повний текст джерелаАнотація:
The amount of (1,3;1,4)-β-D-glucans or mixed-linkage-β-glucans (MLG) in biofuel crops is of interest because this is a source of fermentable hexose sugar. Recent modification of (1,3;1,4)-β-glucan in barley has opened the possibility of increasing the (1,3;1,4)-β-glucan amount in other plants, including bioethanol crops such as sorghum, a C₄ grass. As S. viridis is a model plant for studying C₄ biofuel crops the characteristics of MLG accumulation in S. viridis is of interest. The initial study determines the levels, structure and distribution of MLG in various vegetative tissues and grain in S. viridis, and investigates the relationship with the transcript levels of Cellulose synthase-like (Csl) genes, i.e. genes involve in MLG synthesis. Modification of MLG amount was tested by generating transformants of S. viridis with over-expressing Csl F6 driven by either the oat globulin promoter (ProASGLO) or the constitutive 35S promoter (Pro35S) from barley (HvCslF6) and sorghum (SbCslF6). In addition, a previous study on the over-expression of the (1,3;1,4)-β-glucan synthase in transgenic barley showed an excessive deposition of the polysaccharide in many cell types causing vascular suffocation and sometimes plant death. To resolve this problem this study also aim to identify a sorghum promoter which may be used to regulate the over-expression of (1,3;1,4)-β-D-glucan synthase genes (such as CslF and CslH) and restrict it to certain specific cell types only. Five putative sorghum mesophyll cell-specific promoters from genes involved in C₄ photosynthesis have been fused with a β-glucuronidase (uidA) cDNA. All modifications were tested in planta using stable Agrobacterium-mediated transformation.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2016.
43
Jacobs, Andrew Keith. "(1→3)-β-D-glucan synthases of plants". Thesis, 2003. http://hdl.handle.net/2440/80390.
Повний текст джерелаАнотація:
This thesis investigates the involvement of the plant glucan synthase-like or GSL genes in the formation of callose. Callose is a (1→3)-β-D-glucan widely distributed in higher plants. During normal plant growth, callose is found as a transitory component of the cell plate in dividing cells, it is a major component of pollen mother cell walls and pollen tubes, and is found as a structural component of plasmodesmatal canals, and is also in abscission zones and the phloem of dormant tissues. Callose is also deposited between the plasma membrane and the cell wall following exposure of plants to a range of abiotic and biotic stresses, including wounding, dessication, metal toxicity and microbial attack. Gene isolation was conducted in ryegrass, but functional analyses were conducted in barley. Ultimate proof of function of a single GSL gene was achieved in the plant model Arabidopsis.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2003
44
Kalinga, Danusha Nilakshi. "Delivering β-glucan via selected bakery systems : cake". Thesis, 2010. https://vuir.vu.edu.au/15799/.
Повний текст джерелаАнотація:
In the western world intake of dietary fibre is low and fat consumption is high. This leads to many diet related diseases, such as, type 2 diabetes, colorectal cancer and cardiovascular disease. Fibre enrichment and fat replacement are effective ways in developing a health-promoting diet. β-glucan, a soluble dietary fibre present in cereal grains, has many health benefits, which include reduction in blood cholesterol and, improving insulin response. Due to its viscosity enhancing and water binding properties, β-glucan is considered as a potential fat replacer. In this thesis β-glucan from oat and barley were studied as functional ingredients in bakery systems using cake as a model to deliver health benefits.
45
Chang, Shih-Mei, та 張詩梅. "Manufacture of Fermented Dairy Drink Containing β-D-glucan". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/28043836532092500334.
Повний текст джерелаАнотація:
碩士國立屏東科技大學
畜產系所
97
Kluyveromyces marxianus is one of the main yeast starters of traditional alcoholic fermented milk products, such as kefir and koumiss. K. marxianus can utilize lactose to produce lactic acid and small amounts of ethanol and CO2, which contribute the unique flavor to the fermented products. The main polysaccharides of yeast cell walls, β-1,3/1,6-glucan, are effective at activating and maintaining the activity of immune reactions. The objectives of this study were to produce a functional fermented dairy drink cultured with K. marxianus, and to increase the varieties of dairy products. The physiochemical characteristics and β-D-glucan productivity of the dairy drink during fermentation and storage were investigated. Sensory evaluation of final product was measured. Overall, we aim to develop a highly acceptable functional fermented dairy drink with β-D-glucan and low-levels of ethanol from K. marxianus fermentation. In Experiment I, we established quantitative analysis procedures for measuring β-D-glucan, the functional component in this fermented dairy drink. The excitation wavelength (EX)/emission wavelength (EM), excitation slit width (EX Slit)/emission slit width (EM Slit) of the fluorescence spectrophotometer, and different kinds of quartz cuvettes were tested. Results showed that the optimum conditions for detecting β-D-glucan were EX/EM 395/495 nm, EX Slit/EM Slit 10/20 nm with the fluorescence cuvette. Experiment II compared the quality of functional fermented dairy drinks inoculated with 0.5, 1.0 and 1.5% K. marxianus starter cultures. The functional fermented dairy drink was fermented at 25℃, with agitation (200 rpm) for 15 min, holding for 2 hrs, and agitation again for 22 hrs. Quality analysis of the dairy drink during storage was carried out for 14 days. We measured the physicochemical properties including pH, titratable acidity (TA%), total sugar content (TDS) and ethanol concentration (EtOH%); functional characteristics i.e. β-D-glucan concentration; microbiological properties i.e. total yeast counts (TYC). Sensory evaluation was used to select the optimum K. marxianus starter concentration for producing the functional fermented dairy drink. Results showed that pH value and TDS decreased, but TA%, EtOH% and TYC increased during fermentation for all treatments. The β-D-glucan concentration of functional fermented dairy drink was at the range of 0.40-0.59 mg/mL. The EtOH% and TYC of 0.5-1.5% K. marxianus functional fermented dairy drink at 24th hour fermentation were 1.90-2.30% and 8.17-8.29 log CFU mL-1, respectively. Sensory evaluation showed that the functional fermented dairy drink with 1.0% K. marxianus had the highest overall acceptability (P＜0.05). TDS of functional fermented dairy drink decreased during 14 days storage at 4℃. However, the pH value at the 14th day was higher than 1-7 days during 4℃ storage, but TA% was opposite to the trend of pH value. The EtOH%, β-D-glucan concentration and TYC of 0.5-1.5% K. marxianus functional fermented dairy drink during storage were 2.84-3.99%, 0.40-0.52 mg/mL and 7.85-8.25 log CFU mL-1, respectively. In Experiment III, we analysed the properties of the functional fermented dairy drink manufactured with the optimum K. marxianus concentration, then adjusted the flavor for improving the overall acceptability. The flavor adjustment was executed by adding 2.5, 5.0, 7.5 and 10% passion fruit and peach concentrated juices, respectively. The physicochemical properties analysis and sensory evaluation were carried out on flavor-adjusted products. Results showed that pH value, TDS, TA% and EtOH% of functional fermented dairy drink with 1.0% K. marxianus were 5.48, 8.8 °Brix, 0.52% and 2.14%, respectively. The β-D-glucan, TYC and viscosity of the drink were 0.59 mg/mL, 8.22 log CFU mL-1 and 1.66 cPs, respectively. Furthermore, the L*, a* and b* values of the drink were 88.27, -3.44 and 6.41, respectively. Results of 1.0% K. marxianus functional fermented dairy drink with 2.5-10% passion fruit and peach concentrated juices adjustment showed that flavoring affected some chemical characteristics. Adding concentrated juices dramatically lowered the sensory scores for sourness, bitterness, astringent and ferment flavors, and contribute to an increase in the overall acceptability of functional fermented dairy drink. The treatment with 7.5% peach concentrated juice had the best overall acceptability. However, The functional fermented dairy drink started curdling when the addition of passion fruit concentrated juice was over 7.5%. In conclusion, the functional fermented dairy drink manufactured with 1.0% K. marxianus produced 0.59 mg/mL β-D-glucan after 24 hour fermentation. The characteristics of the product were slightly sour, ethanolic, viscous, effervescent and with good acceptability. Addition of 7.5% peach concentrated juice significantly improved the flavor and overall acceptability of the beverage. The TYC remained constant during two weeks of refrigerated storage. The results of these experiments show the potential for a new functional dairy beverage based on K. marxianus fermentation.
46
Lin, Wei-Cheng, та 林微錚. "The Effects of β-glucan on OVA-sensitizes Mice". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/11448868159054557284.
Повний текст джерелаАнотація:
碩士國立臺灣大學
漁業科學研究所
99
The aim of the experience is to understand mushroom polysaccharides can be prevented of allergy. The design of experiment continuous feeding different concentration of glucan for two weeks (0mg/200μl, 1mg/200μl, 2mg/200μl), and B6 mice were sensitized by OVA from twice to five times. Using different levels of sensitization to know the effect of polysaccharide feeding mice so we detected IFN-γ, IgG2a, IgE and IL-4 concentration in serum of the sensitization mice. Taking advantage of cytokines and immune globulin to study polysaccharides of the efficacy. The results show that B6 mice sensitized several times, the group feeding mushroom polysaccharides of this experimental are eligible for a higher concentration of IFN-γ, and the group sensitized twice and four times by OVA, the experimental group and control group a comparison of significant differences (P <0.05). The IgG2a serum concentrations have similar results to IFN-γ, regardless of the sensitizion frequency,the group feeding glucan may be got higher IgG2a levels. The coparison of the polysaccharide treatment group and control group had a significant difference (P <0.05). The IgE concentrations in serum of feeding polysaccharides of B6 mice are lower than the control group, and the comparison of glucan treatmet and control had a significant difference (P <0.05) of the group sensitized twice to five times. The group fed 1mg/200μl of glucan had higher IL-4 concentrations in serum than any other treatment group or nontreayment froup, and there is significant difference (P <0.05). The result of IL-4 concentration in treatment group were lower than control group whether sensitization twice to five times, but no significant differences. The results show that mushroom polysaccharides can effectively enhance the IFN-γ and IgG2a concentration in the blood and reduce IgE levels, amount regardless of the number of allegens. Mushroom polysaccharides improved response to Th1cells, helps fight allergies, but the effects of IL-4 from mushroom polysaccharide is not obvious in this experiment.
47
Wen, Shih-Ya, та 文詩雅. "Studies on the Enhancement of Cellular Immunity Using Mushroom β- Glucan". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/05913408049973864623.
Повний текст джерелаАнотація:
碩士國立臺灣大學
漁業科學研究所
96
Mushroom has a long history of use in folk medicine. It has been report that mushroom contains various biologically active compounds, especially, such as beta-glucan. In the present study, C57BL/6 mice were orally administered mushroom beta-glucan, and antitumor immunity was examined. The result revealed higher level of NK cell-mediated cytotoxicity after treating with beta-glucan for 14 days in tumor-unbearing mice. The inhibition of tumor growth in Lewis lung carcinoma (LLC)-bearing mice treated with beta-glucan has been observed. Oral administration of mushroom beta-glucan in different concentrations significantly reduced the tumor weight in a dose-dependent manner, with an inhibition more than 70%. It also shows the treatment of the highest concentration of glucan elevated the cytotoxicity of natural killer cell and the mitogen-induced lymphoproliferative activity of spleen cells. In pre- and simultaneous treatment, the inhibition of tumor growth are higher than control group. After pre-treatment of glucan, the proliferation of lymphocytes is significantly increased. In conclusion, the beta-glucan derived from the mushroom could be used as immunomodulator and anti tumor agent in mice.
48
Hsieh, Hsiao-Huan, та 謝曉環. "Research on purification of β-(1,3)/(1,6)-glucan from Saccharomyces cerevisiae". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/97055467471578546056.
Повний текст джерелаАнотація:
碩士國立高雄應用科技大學
化學工程系碩士班
92
β-(1,3)/(1,6)-glucans are the polymers of (1,3)-β-linked glucopyranos with the branch of (1,6)-β-linked glucopyranos. These glucans have been shown to have immunopharma- cological activity in humans and animals. This study present a process for isolation of β-(1,3)/(1,6)-glucans from baker’s yeast (Saccharomyces cerevisiae), together with compositions and methods of treatment. The process of the study comprises the steps of: (a) extracting alkali soluble components from cells with alkali and heat; (b) extracting the chitins from the cell wall with acid and heat; (c) extracting lipids with ethanol and recovered the β-(1,3)/(1,6)-glucan; and (d) using the different drying methods to give microparticulate glucan. The comparison of FTIR for the products of every step in process, the significant spectral 891 cm-1 is attributed to a β-(1,3)/(1,6)-glucan which is identified the product from the fractionation procedure. Hot sodium bicarbonate and sodium hydroxide can be very efficient to remove proteins and alkali-soluble mannoprotein from yeast. The chitin dissolves in hot acetic acid. After ethanol extraction and removal of the lipids, the insoluble residue contained pure β-(1,3)/(1,6)-glucan. From the FTIR and NMR analytical data, the purified β-(1,3)/(1,6)-glucan is found to have exclusively high purity. The electron microscopy SEM and TEM show that the three different drying β-(1,3)/(1,6)-glucan products have platelet particle aggregates which form a large particle size. The average thickness of platelets is measured to be less than 100nm. The drying products contain 13% water from the TGA/DTA measurements. After heating to above 260℃, the β-(1,3)/(1,6)-glucan decomposed to CO2 and H2O. Structural studies of β-(1,3)/(1,6)-glucan from diffraction patterns recorded by X-ray and TEM have revealed that these spacings are roughly in agreement with a tetragonal unit cell of dimensions a = 0.878 nm c = 0.872 nm for ether drying products, a = 0.866 nm c = 0.844 nm for lyophilization drying products, respectively. The process is simple、fast and ease. The resulting glucan is obtained in high yields to about 10.5 % with high purity. The mannoprotein is also obtained as a byproduct.
49
Repin, Nikolay. "Mechanisms of stabilizing fibre-enriched acidified dairy products." 2011. http://hdl.handle.net/1993/4350.
Повний текст джерелаАнотація:
Acidified dairy products are one of the oldest types of food products. Unfortunately all of them are low in dietary fibre. Thus, to improve health benefit of these products the idea of fortifying them with dietary fibre seems attractive. However dairy products enriched with Glucagel (a commercial product that is high in barley β-glucan) were found to suffer from textural defects. When the Glucagel concentration exceeded a certain value (5 g/L), dramatic phase separation was observed in set yogurt and yogurt drink with volume fraction of casein micelles greater then 0.108. To investigate interactions of β-glucan polymers and casein micelles in the milk prior to setting of yogurt, mixtures of yogurt milk and Glucagel were systematically studied. Depending on the volume fraction of casein micelles and the Glucagel concentration, a stable phase or a gel or a sedimented material could exist. The driving force for phase separation was depletion flocculation of casein micelles in the presence of β-glucan. The phase separation responsible for textural defects in yogurt systems supplemented with high amounts of Glucagel can be avoided by the reduction of β-glucan molecular weight, a process that limits the range of attraction between micelles. Incubation of Glucagel with lichenase for 90 min resulted in homogeneous (stable) yogurt systems with Glucagel concentrations as high as 10 g/L.
50
Li, Jing. "Studies on (1→3)-[β]-glucan synthases in barley / by Jing Li". Thesis, 2003. http://hdl.handle.net/2440/22053.
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Bibliography: leaves 132-155.viii, 155 leaves : ill., plates, charts (some col.) ; 30 cm.
A putative callose synthase gene, designated HvGSL1 cDNA is siolated from barley and its involvement in callose biosynthesis is investigated. A near-full length HvGSL1 cDNA encoded a protein showing approximately 30% identitly with that of yeast FKS genes at the amino acid level. The function of this geen was investigated by heterologous expression, protein purification, immunochemistry and mass spectrometric analysis. Results provide strong evidence that the gene encodes a protein which is associated with callose synthase activity, and is likely to encode the catalytic subunit of the synthase complex.
Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 2003