Dissertations / Theses on the topic 'Starch Synthesis'
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1
Entwistle, Tina Gail. "Synthesis of storage starch." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316826.
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Ponstein, Anne Silene. "Starch synthesis in potato tubers." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 1990. http://irs.ub.rug.nl/ppn/291023398.
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Sweetlove, Lee. "The control of starch synthesis." Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264287.
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Clarke, Belinda. "The rate of starch synthesis as a determinant of starch composition." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267540.
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Kolbe, Anna. "Redox-regulation of starch and lipid synthesis in leaves." Phd thesis, [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978968182.
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Baguma, Yona. "Regulation of starch synthesis in cassava /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a478.pdf.
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Peloewetse, Elias. "Control of starch synthesis in leaves." Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326644.
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Blissett, Kerry Joy. "Starch synthesis in developing wheat endosperm." Thesis, University of Manchester, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488035.
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This work has investigated the permeability of amyloplasts isolated from developing wheat endosperm to a range of metabolites that could be taken lip by the amyloplasts for starch synthesis and carbohydrate oxidation. A rapid method for the isolation and purification of amyloplasts from the endosperm of spring wheat, Triticum aestivum L.cv Axona, has been developed. Amyloplasts were mechanically released from cells of plasmolysed endosperm tissue and purified by low speed centrifugation through 2% Nycodenz onto an agar cushion. Amyloplasts prepared by this method were routinely 55-65% intact and the recovery was greater than 20% as determined by the plastid marker enzyme, alkaline inorganic pyrophosphatase (APPase). Contamination by the cytosol determined by UDP-glucose pyrophosphorylase and alcohol dehydrogenase was less than 1% whilst the contamination attributable to mitochondria, the endomembrane system and microbodies was 0.2%, 0.5% and 0% respectively. Amyloplast integrity was dependent upon the sorbitol concentration of the extraction buffer and at the optimal concentration of O.8M sorbitol, intactness was maintained for up to 2 hours. Proteolytic protection experiments demonstrated that amyloplast marker enzymes were protected from digestion with trypsin. Preparations incubated with a range of [U_14C] labelled substrates, in the presence and absence of ATP, were able to support starch synthesis at physiological rates similar to rates obtained in whole endosperm when supplied with 5 mM GlclP and 1 mM ATP or 5 mM ADP-glucose. The Km for GlclP was calculated as 0.46 mM. The ability of amyloplast preparations to support starch synthesis from GlclP and ATP in the presence of known translocator inhibitor compounds was examined. DIDS, P5P and CAT, inhibitors of the phosphate and adenylate trans locators, reduced the amount label incorporation from [U_14C] GlclP, supplied in the presence of ATP, into starch by up to 80%. Stimulation" of the OPPP by the addition of substrates for the glutamate synthase reaction, 2-oxoglutarate and glutamine in the presence of either Gle 1P or Glc6P and ATP resulted in an asymmetric distribution of carbon utilisation between starch synthesis and carbohydrate oxidation. 14C from supplied [U_I4C] GlclP and [U_14C] Glc6P was measured in synthesized starch and evolved CO2. Whilst GlclP was clearly the preferred substrate for starch synthesis, Glc6P was readily oxidised when 2-oxoglutarate and glutamine were supplied to isolated plastid preparations. Metabolite levels inside the amyloplast were quantified under different conditions of starch synthesis and carbohydrate oxidation. Under conditions in which the OPPP was not stimulated, GlclP demonstrated no interconversion to Glc6P, suggesting that the enzyme which interconverts the two compounds is not catalysing an equilibrium reaction and may be the regulatory branchpoint between the pathways of starch biosynthesis and carbohydrate oxidation.
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Mitchell, Angela. "The effect of temperature on starch synthesis." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243060.
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Sugih, Asaf Kleopas. "Synthesis and properties of starch based biomaterials." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2008. http://irs.ub.rug.nl/ppn.
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Hawker, John Seth. "Sucrose and starch metabolism in leaves, storage organs and developing fruits of higher plants." Title page, contents and summary only, 1988. http://web4.library.adelaide.edu.au/theses/09SD/09sdh392.pdf.
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Forrest, Sharon Irene. "The metabolism of starch in effective and ineffective nodules of soybean /." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=64078.
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Dutton, Sarah L. "The regulation of starch synthesis in non-photosynthetic tissues." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289285.
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Tomlinson, Kim Louise. "Starch synthesis in leaves of pea (Pisum sativum L.)." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297009.
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Chauhan, Geeta. "Molecular characterisation of the small and large subunits of ADP-glucose pyrophosphorylase genes in Solanum tuberosum L." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281956.
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Shah, Brinda. "Synthesis of polyethylene/starch hybrids using aqueous mini emulsion polymerization /." Online version of thesis, 2010. http://hdl.handle.net/1850/12265.
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Wallwork, Meredith Anne Blesing. "Investigation of the physiological basis of malting quality of grain developing under high temperature conditions." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phw215.pdf.
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Bibliography: leaves 174-192. This research aims to obtain detailed knowledge on the effects of a period of high temperature on the accumulation of grain dry matter and endosperm starch, protein and B-glucan in the developing grain of the malting barley variety Schooner. Bbarley plants are exposed to high temperatures during mid grain filling for 5 days. Grain growth characteristics are measured prior to, during and following the high temperature period, with the aim of characterising the high temperature response in developing grain. The activities of several enzymes and metabolities of the pathway of starch synthesis are monitored and compared to those in grains maintained at a lower temperature. In addition, grain structure is also compared between control and heat treated grain during development, at maturity and following malting.
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Tillett, Ian J. L. "The size distribution and synthesis of starch granules in cereal endosperms." Thesis, Heriot-Watt University, 1996. http://hdl.handle.net/10399/733.
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Anthony, Renil John. "Cationic Starch Synthesis, Development, and Evaluation for Harvesting Microalgae for Wastewater Treatment." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/2005.
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In the quest for a feedstock for the production of biofuels, microalgae are showing potential. High photosynthetic efficiency, combined with high lipid content and low fresh water requirement, has contributed to the 'biofuels feedstock' status of microalgae. In some communities, microalgae have also been cultivated in wastewater in facultative lagoons to remove phosphorus and nitrogen through the growth of microalgae. With such systems in place, complete biological wastewater treatment can be achieved and the harvested microalgae could provide feedstock for biodiesel and various other bioproducts.
Due to small cell size, low culture concentrations, and the electrostatic repulsive forces that keep the cells in suspension, harvesting microalgae entails high energy inputs and associated high costs. Of the several harvesting methods tested, chemical precipitation has been shown to be the only method to harvest microalgae on a large scale. Although effective in wastewater treatment, the use of inorganic metal coagulants for microalgae harvesting leads to high dosage requirements, excess volume of sludge, and high costs, and due to the presence of associated metal hydroxide, the harvested biomass is unsuitable as feedstock for bioproducts.
The drawbacks of inorganic coagulants for microalgae harvesting can be overcome by using cationic starch. Corn and potato starch were cationized using 3-methacryloyl amino propyl trimethyl ammonium chloride and biogenic amines. Flocculation efficiencies of the cationic starches were tested in a jar test apparatus using single strain microalga, Scenedesmus obliquus, and mixed culture wastewater from the Logan City, Utah lagoons. Cationic starches showed better or comparable removal of total suspended solids compared to aluminum sulfate. Total phosphorus removal efficiencies for cationic starches were lower compared to aluminum sulfate. Effect of cationic starch harvested and alum harvested S. obliquus on biodiesel, acetone, butanol, ethanol production, and Escherichia coli growth was also studied. Results suggested significantly higher yields of bioproducts when cationic starch was used to harvest microalgae and the biomass was used as feedstock.
Cationic starches are an organic, sustainable, and renewable form of coagulant/flocculant. The use of cationic starch for harvesting microalgae eliminates the need for metal salts while enhancing the production of algae-based bioproducts. Cationic starch along with advanced technologies in the processing of microalgae is the way forward in the realization of the “microalgae to biofuels” initiative.
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Tang, Xiaozhi. "Use of extrusion for synthesis of starch-clay nanocomposites for biodegradable packaging films." Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/546.
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Hill, Loinel Mark. "The source of carbon for starch synthesis by amyloplasts from developing pea embryos." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334704.
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Craig, Josephine. "The use of mutants to understand starch synthesis in the pea (Pisum sativum L.) plant." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338244.
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Goodpaster, Bret H. "The effects of pre-exercise starch feedings on blood glucose responses and performance during strenuous exercise." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941582.
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This study compared the exercise responses of a waxy starch (WS), resistant starch (RS), glucose (GL) and an artificially-sweetened placebo (PL) ingested prior to exercise. Ten college-age, male competitive cyclists completed four experimental protocols consisting of a 30 min isokinetic, self-paced performance ride preceded by 90 min of constant load cycling at 66% VO2max. Thirty min prior to exercise, they ingested 1 g•kg-1 body weight of GL, WS, RS, or PL. A familiarization trial was first conducted to eliminate a potential order effect. An order effect was evidenced by lower (p<0.05) work rates during the performance ride of the first trial (390 ± 26.1 kJ) than the other four trials. No order effect was observed for the remainder of the experimental treatments which were performed in a single-blind, randomized fashion. At rest, GL elicited greater (P<0.05) serum glucose and insulin responses than all other trials. During exercise, however, serum glucose and insulin responses were similar among trials. Blood C-peptide and glucagon responses were also similar among trials. The mean total carbohydrate oxidation rates (CHOox) were higher (p<0.05) during the GL, WS, and RS trials (2.59 ± 0.13, 2.49 ± 0.10, and 2.71 ± 0.15 g•min-1, respectively) compared to PL (2.35 ± 0.12 g•min-1). Subjects were able to complete more work (p<0.05) during the performance ride when they ingested GL (434 ± 25.2 kJ) or WS (428 ± 22.5 kJ) compared to PL (403 ± 35.1 kJ). They also tended to produce more work with RS ingestion (418 ± 31.4 kJ), although this did not reach statistical significance (p<0.09). These results indicate that pre-exercise CHO ingestion in the form of starch or glucose maintained higher rates of total carbohydrate oxidation during exercise and provided an ergogenic benefit during self-paced cycling.Human Performance Laboratory
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Kang, Fan. "Carbon sources for starch and fatty acid synthesis in plastids from developing embryos of oilseed rape." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240398.
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Zakharova, K., A. Mednikova, V. Rumyantsev, and T. Genusova. "Synthesis of Boron Carbide from Boric Acid and Carbon-Containing Precursors." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35601.
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The paper compares low-temperature techniques for boron carbide synthesis. Boron carbide was syn-thesized via reaction between boric acid and various carbon precursors, e.g. phenol-formaldehyde resin, su-crose, carbon black, and potato starch. Initial compositions and carbon precursor preparation techniques were selected for synthesis. The resulting products were characterized by IR spectrometry, X-ray diffrac-tion (XRD) and scanning electron microscopy. Possible boron carbide yields up to 95 % of the theoretical yield as calculated from initial boron contents at temperatures of 1550 oС were demonstrated. XRD con-firmed that the synthesized boron carbide (B4C) has a rhombohedral crystalline structure. Final product morphology may be tailored, ranging from isometric to needle-like crystallite morphology. Nanopowders as processed via high-energy milling may be further used as sintering additive for processing of boron carbide ceramics.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35601
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Herrera, y. Saldana Rolando Ernesto. "The effect of synchronization of protein and starch degradation in the rumen on nutrient utilization and milk production in dairy cows." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184373.
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Four studies were conducted to determine the effect of synchronization of protein and starch degradation on nutrient utilization, microbial protein synthesis and milk production in dairy cows. In Experiment 1, five cereal grains and five protein supplements were compared for extent of solubility and degradability of their starch and nitrogen fractions. Results indicated large differences which permitted their ranking from high to low degradability as follows: grains, oats > wheat > barley > corn > milo protein supplements, soybean meal > cottonseed meal, (CSM) > corn gluten meal > brewers dried grains, (BDG) > blood meal. In Experiment 2, the five grains were incubated for varying times in vitro (with added amylase) or in situ to determine rate and extent of degradation of dry matter, crude protein and starch. Results showed that rate of starch degradation followed a similar, but slightly different trend than in trial 1 (wheat > barley > oats > corn > milo). Rates for DM and CP degradation were similar than those for starch. In Experiment 3, high (barley, HS) and low (milo, LS) degradable starch sources were combined with a high (CSM, HP) and a low (BDG, LP) degradable protein sources to formulate four diets; HSHP, HSLP, LSHP and LSLP. Diets were fed to 32 cows, starting two to four weeks postpartum, for a 60-d milk production and digestibility study. Apparent digestibility was calculated using chromium oxide. Organic matter digestibility was higher (P < .05) was found in nutrient output to the small intestine among diets and microbial CP synthesis was higher (P > .05) for barley diets.
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Ferreira, Stephanus Johannes. "The analysis and reduction of starch in sugarcane by silencing ADP-glucose pyrophosphorylase and over-expressing β-amylase." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/2880.
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Thesis (MSc (Plant Biotechnology))--University of Stellenbosch, 2007.Sugarcane is cultivated because of the high levels of sucrose it stores in its internodes. Starch metabolism has been a neglected aspect of sugarcane research despite the problems caused by it during sugarcane processing. Currently there is no information available on the starch content in different South African commercial sugarcane varieties. This project had two main aims of which the first was to determine the starch content in the internodal tissues of six commercial sugarcane varieties. The activities of ADP-Glucose Pyrophosphorylase (AGPase) and β- amylase were also determined. The second aim of the project was to manipulate starch metabolism in sugarcane using transgenesis. To achieve this, transformation vectors for the down-regulation of AGPase activity and over-expression of β-amylase activity were designed. These vectors were then used to transform sugarcane calli and the results were analysed in suspension cultures. Starch levels in sugarcane internodal tissue increased more than 4 times from young to mature internodes. There were also large differences between varieties. When mature tissues of different varieties were compared, their starch concentration varied between 0.18 and 0.51 mg g-1 FW, with the majority of the varieties having a starch concentration between 0.26 and 0.32 mg g-1 FW. NCo376’s starch concentration was much lower than the rest at 0.18 mg g-1 FW and N19’s was much higher at 0.51 mg. g-1 FW. There was also a very strong correlation between starch and sucrose concentration (R2 = 0.53, p ≤ 0.01) which could be due to the fact that these metabolites are synthesized from the same hexose-phosphate pool. No correlation was evident between starch concentration and AGPase activity. This was true for correlations based on either tissue maturity or variety. β-amylase activity expressed on a protein basis was almost 5 times higher in the young internodes compared to mature internodes, suggesting that carbon might be cycled through starch in these internodes. AGPase activity in the transgenic suspension cultures was reduced by between 0.14 and 0.54 of the activity of the wild type control. This reduction led to a reduction in starch concentration of between 0.38 and 0.47 times that of the wild type control. There was a significant correlation between the reduction in AGPase activity and the reduction in starch (R2 = 0.58, p ≤ 0.05). β-amylase activity in the transgenic suspension cultures was increased to 1.5-2 times that of the wild type control. This led to a reduction in starch concentration of between 0.1 and 0.4 times that of the wild type control. Once again the increase in β-amylase activity could be correlated to the reduction in starch concentration of the transgenic suspension cultures (R2 = 0.68, p ≤ 0.01). In both experiments there was no significant effect on sucrose concentration.
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Xu, Jingwen. "Biobased nanocomposites for packaging applications — synthesis using melt extrusion of poly (lactic acid), poly (butylene succinate) and/or starch blended with natural nanofillers." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20561.
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Master of ScienceDepartment of Grain Science and Industry
Sajid Alavi
There is a renewed focus on biodegradable polymers in packaging applications due to environmental concerns associated with conventional plastics. Melt extrusion was used to synthesize nanocomposites from poly (lactic acid) (PLA) or poly (butylene succinate) (PBS) blended with natural nanofillers — chitin whiskers (CHW, 1-5%), nanocrystalline cellulose (NCC, 1-5%) or lignin-coated nanocrystalline cellulose (LNCC, 3%). Transmission electron microscopy and x-ray diffraction indicated that the natural nanofillers were uniformly dispersed in the polymer matrix. For PLA based nanocomposites, differential scanning calorimetry showed a decrease in change of heat capacity at glass transition (ΔCp) with increased nanofiller addition, indicating greater confinement of polymer chains. For PBS based nanocomposites, nanofillers acted as nucleating agents and promoted recrystallization of polymer as reflected in increase of degree of crystallinity (Xc) from 65.9-66.8 to 75.6%. By addition of NCC and CHW, tensile strength (TS) of PLA based films increased from 50.2 MPa to 70.9 MPa and 52.1 MPa, respectively, while TS of PBS increased from 23.2-24.9 MPa to 32.9 MPa and 43.6 MPa, respectively. Elongation at break (E%) of nanocomposite films ranged from 9.1 to 15.3, and in general decreased with addition of nanofillers. LNCC did not significantly improve mechanical properties of PBS and PLA films. Additionally, 3% NCC addition reduced oxygen transmission rate (OTR) of PLA from 209.9 to 180.8 cc/m[superscript]2/day, which further reduced to 109.3 cc/m[superscript]2/day by adding compatibilizer methylene diphenyl diisocyanate (MDI, 4%). Water vapor transmission rate (WVTR) of PLA also reduced from 44.4 to 28.6 g/m[superscript]2/day with 3% NCC and 4% MDI addition. Similarly OTR and WVTR of PBS decreased from 737.7 to 280 cc/m[superscript]2/day and 83.8 to 49.4 g/m[superscript]2/day, respectively with 3% NCC. Use of 4% MDI further reduced OTR and WVTR to 23.8 cc/m[superscript]2/day and 30.8 g/m[superscript]2/day, respectively. Use of starch can potentially reduce the costs of bio-based nanocomposites films. Up to 40% starch was incorporated during synthesis of PLA and NCC nanocomposites using solution mixing method. Addition of starch decreased TS from 35.8 MPa to 18.4 MPa and E% from 8.3% to 6.0%. Use of NCC (1%) and MDI (4%) improved the mechanical properties to a certain extent.
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Besheer, Ahmed Ibrahim Hamed [Verfasser], Karsten [Akademischer Betreuer] Mäder, Jörg [Akademischer Betreuer] Kressler, and Alfred [Akademischer Betreuer] Fahr. "Nanomedicines based on modified hydroxyethyl starch : from synthesis to in vivo evaluation / Ahmed Ibrahim Hamed Besheer. Betreuer: Karsten Mäder ; Jörg Kressler ; Alfred Fahr." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2009. http://d-nb.info/1024859061/34.
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Liiving, Tiina Verfasser], Björn [Akademischer Betreuer] Junker, Eva Maria [Akademischer Betreuer] Farré, and Nicolaus von [Akademischer Betreuer] [Wirén. "Subcellular network of starch synthesis in maturing embryos of pea Pisum sativum L. (Fabaceae) / Tiina Liiving. Betreuer: Björn Junker ; Eva Maria Farré ; Nicolaus Wirén." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2015. http://d-nb.info/1067842616/34.
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Gibbs, Bernard F. "Characteristics of isolated and synthetic a-amylase inhibitors." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24006.
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Effective inhibition of starch digestion in vivo may diminish glucose formation and absorption by the small intestine and increase the amount of undigested starch reaching the colon. The enzyme involved in the digestion of starch, alpha-amylase, has been identified and crystallized several years ago. Controversy exists as to whether effective inhibition can decrease starch digestion sufficiently to result in weight loss. The objective of this project is (a) to isolate and characterize alpha-amylase inhibitors from Phaseolus species (b) to synthesize and characterize known inhibitors in an effort to understand their mechanism of action.The supernatant from ground beans was subjected to reverse phase chromatography. The separated peaks were lyophilized and assayed for alpha-amylase inhibitory activity. The inhibitor with the highest activity (peak 6) was repurified and fully characterized. It was exposed to physiological amounts of endoproteases to check its stability.
A known inhibitor of alpha-amylase was synthesized and studied. Its binding constant has not been previously reported. (Abstract shortened by UMI.)
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Ihemere, Uzoma Enyinnaya. "Somatic embryogenesis and transformation of cassava for enhanced starch production." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1070549008.
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Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xxiii, 184 p.; also includes graphics (some color). Includes bibliographical references (p. 166-184).
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Winkler, Henning. "Synthese von thermoplastisch verarbeitbaren Fettsäure-Acylderivaten der Stärke und Proteine." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2014/7108/.
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In den vergangenen Jahren wurden stetig wachsende Produktionskapazitäten von Biokunststoffen aus nachwachsenden Rohstoffe nverzeichnet. Trotz großer Produktionskapazitäten und einem geeigneten Eigenschaftsprofil findet Stärke nur als hydrophile, mit Weichmachern verarbeitete thermoplastische Stärke (TPS) in Form von Blends mit z. B. Polyestern Anwendung. Gleiches gilt für Kunststoffe auf Proteinbasis. Die vorliegende Arbeit hat die Entwicklung von Biokunststoffen auf Stärkebasis zum Ziel, welche ohne externe Weichmacher thermoplastisch verarbeitbar und hydrophob sind sowie ein mechanisches Eigenschaftsprofil aufweisen, welches ein Potenzial zur Herstellung von Materialien für eine Anwendung als Verpackungsmittel bietet. Um die Rohstoffbasis für Biokunststoffe zu erweitern, soll das erarbeitete Konzept auf zwei industriell verfügbare Proteintypen, Zein und Molkenproteinisolat (WPI), übertragen werden. Als geeignete Materialklasse wurden Fettsäureester der Stärke herausgearbeitet. Zunächst fand ein Vergleich der Säurechlorid-Veresterung und der Umesterung von Fettsäurevinylestern statt, woraus letztere als geeignetere Methode hervorging. Durch Variation der Reaktionsparameter konnte diese optimiert und auf eine Serie der Fettsäurevinylester von Butanoat bis Stearat für DS-Werte bis zu 2,2-2,6 angewandt werden. Möglich war somit eine systematische Studie unter Variation der veresterten Fettsäure sowie des Substitutionsgrades (DS). Sämtliche Produkte mit einem DS ab 1,5 wiesen eine ausgprägte Löslichkeit in organischen Lösungsmitteln auf wodurch sowohl die Aufnahme von NMR-Spektren als auch Molmassenbestimmung mittels Größenausschlusschromatographie mit gekoppelter Mehrwinkel-Laserlichtstreuung (GPC-MALLS) möglich waren. Durch dynamische Lichtstreuung (DLS) wurde das Löslichkeitsverhalten veranschaulicht. Sämtliche Produkte konnten zu Filmen verarbeitet werden, wobei Materialien mit DS 1,5-1,7 hohe Zugfestigkeiten (bis zu 42 MPa) und Elastizitätsmodule (bis 1390 MPa) aufwiesen. Insbesondere Stärkehexanoat mit DS <2 sowie Stärkebutanoat mit DS >2 hatten ein mechanisches Eigenschaftsprofil, welches insbesondere in Bezug auf die Festigkeit/Steifigkeit vergleichbar mit Verpackungsmaterialien wie Polyethylen war (Zugfestigkeit: 15-32 MPa, E-Modul: 300-1300 MPa). Zugfestigkeit und Elastizitätsmodul nahmen mit steigender Kettenlänge der veresterten Fettsäure ab. Ester längerkettiger Fettsäuren (C16-C18) waren spröde. Über Weitwinkel-Röntgenstreuung (WAXS) und Infrarotspektroskopie (ATR-FTIR) konnte der Verlauf der Festigkeiten mit einer zunehmenden Distanz der Stärke im Material begründet werden. Es konnten von DS und Kettenlänge abhängige Glasübergänge detektiert werden, die kristallinen Strukturen der langkettigen Fettsäuren zeigten einen Schmelzpeak. Die Hydrophobie der Filme wurde anhand von Kontaktwinkeln >95° gegen Wasser dargestellt. Blends mit biobasierten Polyterpenen sowie den in der Arbeit hergestellten Zein-Acylderivaten ermöglichten eine weitere Verbesserung der Zugfestigkeit bzw. des Elastizitätsmoduls hochsubstituierter Produkte. Eine thermoplastische Verarbeitung mittels Spritzgießen war sowohl für Produkte mit hohem als auch mittlerem DS-Wert ohne jeglichen Zusatz von Weichmachern möglich. Es entstanden homogene, transparente Prüfstäbe. Untersuchungen der Härte ergaben auch hier für Stärkehexanoat und –butanoat mit Polyethylen vergleichbare Werte. Ausgewählte Produkte wurden zu Fasern nach dem Schmelzspinnverfahren verarbeitet. Hierbei wurden insbesondere für hochsubstituierte Derivate homogenen Fasern erstellt, welche im Vergleich zur Gießfolie signifikant höhere Zugfestigkeiten aufwiesen. Stärkeester mit mittlerem DS ließen sich ebenfalls verarbeiten. Zunächst wurden für eine Übertragung des Konzeptes auf die Proteine Zein und WPI verschiedene Synthesemethoden verglichen. Die Veresterung mit Säurechloriden ergab hierbei die höchsten Werte. Im Hinblick auf eine gute Löslichkeit in organischen Lösungsmitteln wurde für WPI die Veresterung mit carbonyldiimidazol (CDI)-aktivierten Fettsäuren in DMSO und für Zein die Veresterung mit Säu-rechloriden in Pyridin bevorzugt. Es stellte sich heraus, dass acyliertes WPI zwar hydrophob, jedoch ohne Weichmacher nicht thermoplastisch verarbeitet werden konnte. Die Erstellung von Gießfolien führte zu Sprödbruchverhalten. Unter Zugabe der biobasierten Ölsäure wurde die Anwendung von acyliertem WPI als thermoplastischer Filler z. B. in Blends mit Stärkeestern dargestellt. Im Gegensatz hierzu zeigte acyliertes Zein Glasübergänge <100 °C bei ausreichender Stabilität (150-200 °C). Zeinoleat konnte ohne Weichmacher zu einer transparenten Gießfolie verarbeitet werden. Sämtliche Derivate erwiesen sich als ausgeprägt hydrophob. Zeinoleat konnte über das Schmelzspinnverfahren zu thermoplastischen Fasern verarbeitet werden.In recent years, a steadily growing production capacity of bioplastic based on renewable resources was noticed. Despite its huge production capacities and an appropriate property profile (ubiquitous occurrence, easy extraction), starch is only applied in addition of plasticizers in a hydrophilic, thermoplastic form in blends with e. g. polyesters. The same applies to bioplastics based on proteins. The actual study has the aim to develop starch-based bioplastics, which are hydrophobic, thermoplastic without the addition of any plasticizer and have mechanical properties to be a suitable alternative material in the area of food packaging. To obtain a variation of the raw materials for bioplastics, the concept shall be applied to two types of industrial available proteins, whey protein isolate (WPI) and Zein. Fatty acid esters of starch came out to be a suitable class of materials. Initially, the methods of esterifying acid chlorides and the transesterification of fatty acid vinyl esters were compared with the latter being more appropriate. Reaction parameters of this method were optimized and it was applied to a complete series of vinyl ester reagents (butanoate to stearate), leading to degree of substitution (DS)-values up to 2.2-2.6. With that, a systematic study of the variation of the fatty acid ester chain as well as the DS became possible. It came out that all products with a DS >1.5 showed a well-marked solubility in organic solvents, whereby solution NMR-studies as well as measurements of the molecular weight distributions by using size exclusion chroma-tography with multi-angle laser light scattering (SEC-MALLS) were possible. The different solution behavior was studied by dynamic light scattering (DLS). All soluble products could be formed into films via casting, where materials with a DS of 1.5-1.7 showed the highest values concerning tensile strength (up to 42 MPa) and Youngs modulus (up to 1390 MPa). Especially starch hexanoate with DS <2 and starch butanoate with a DS >2 revealed mechanical properties which are comparable to usually applied polymers for food packaging, e. g. polyethylene (tensile strength: 15-20 MPa, E-Mod: 300-1300 MPa). Tensile strength and Youngs modulus were reduced with increasing length of the esterified fatty acid. Wide-angle X-Ray scattering (WAXS) and infrared spectroscopy (ATR-FTIR) explained this tendency by an increasing intermolecular distance of the starch in the material. Glassy transitions of the materials were detected and showed a dependency on the type of esterified fatty acid and the DS. The crystalline structures of the esterified long-chain fatty acids revealed a melting peak. All films came out to be hydrophobic with contact angles against water >95°. The tensile strength and the Youngs modulus of the highly substituted products could be further improved by blending them with biobased polyterpenes as well as the acylated Zein. A thermoplastic processing without the use of any plasticizer additives was possible for products with a medium and high DS. Homogeneous, transparent testing specimens were obtained. The specific mechanical values were comparable with the casted films, although the highest values for the tensile strength and the elongation were lower. Investigations of the hardness showed comparable values to polyethylene. Selected samples were further processed to fibers by melt spinning. Especially starch esters with high DS revealed homogeneous fibers with a significant increase in the tensile strength compared to the film or testing specimen. Even fatty acid starch esters with a medium DS were processed by the melt-spinning, but their higher glassy transition lead to a reduced softening behavior. To transfer this concept to the class of proteins, different methods of synthesis were studied in the first step, which differed in their amount of acylation. The acylation using fatty acid chlorides lead to highest values. With regard to a well-marked organic solvent solubility, in the case of WPI the acylation with carbonyldiimidazol (CDI)-activated fatty acid was established. For Zein, the acid chloride acylation in pyridine gave the desired results. It came out the fatty acid acylated soluble WPI could not be thermoplastic processed without additional plasticizers. By using biobased oleic acid as additive, the potential of acylated WPI as a thermoplastic filler in blends with e. g. fatty acid esters of starch was shown. In contrast, fatty acid acyl derivatives of Zein revealed well marked glassy transitions <100 °C with an adequate thermal stability. While Zeinoleate could be formed into transparent films via solvent casting without any plasticizer additives, low amounts of tall oil enabled film-forming in the case of acyl derivatives with shorter fatty acids as well. All derivatives revealed a well-marked hydrophobicity. Finally, Zeinoleate was thermoplastically processed into fibers by melt-spinning without any further additives.
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Kim, Jae Eung. "In Vitro Synthetic Biology Platform and Protein Engineering for Biorefinery." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/86645.
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In order to decrease our dependence on non-renewable petrochemical resources, it is urgently required to establish sustainable biomass-based biorefineries. Replacing fossil fuels with renewable biomass as a raw feedstock for the production of chemicals and biofuels is a main driving force of biorefinering. Almost all kinds of biomass can be converted to biochemicals, biomaterials and biofuels via continuing advances on conversion technologies. In vitro synthetic biology is an emergent biomanufacturing platform that circumvents cellular constraints so that it can implement some biotransformations better than whole-cell fermentation, which spends a fraction of energy and carbon sources for cellular duplication and side-product formation. In this work, the in vitro synthetic (enzymatic) biosystem is used to produce a future carbon-neutral transportation fuel, hydrogen, and two high-value chemicals, a sugar phosphate and a highly marketable sweetener, representing a new portfolio for new biorefineries.
Hydrogen gas is a promising future energy carrier as a transportation fuel, offering a high energy conversion efficiency via fuel cells, nearly zero pollutants produced to end users, and high mass-specific and volumetric energy densities compared to rechargeable batteries. Distributed production of cost-competitive green hydrogen from renewable biomass will be vital to the hydrogen economy. Substrate costs contribute to a major portion of the production cost for low-value bulk biocommodities, such as hydrogen. The reconstitution of 17 thermophilic enzymes enabled to construct an artificial enzymatic pathway converting all glucose units of starch, regardless of the branched and linear contents, to hydrogen gas at a theoretic yield (i.e., 12 H2 per glucose), three times of the theoretical yield from dark microbial fermentation. Using a biomimetic electron transport chain, a maximum volumetric productivity was increased by more than 200-fold to 90.2 mmol of H2/L/h at a high starch concentration from the original study in 2007.
In order to promote economics of biorefineries, the production of a sugar phosphate and a fourth-generation sweetener is under development. D-xylulose 5-phosphate (Xu5P), which cannot be prepared efficiently by regular fermentation due to the negatively charged and hydrophilic phosphate groups, was synthesized from D-xylose and polyphosphate via a minimized two-enzyme system using a promiscuous activity of xylulose kinase. Under the optimized condition, 32 mM Xu5P was produced from 50 mM xylose and polyphosphate, achieving a 64% conversion yield, after 36 h at 45 °C. L-arabinose, a FDA-approved zero-calorie sweetener, was produced from D-xylose via a novel enzymatic pathway consisting of xylose isomerase, L-arabinose isomerase and xylulose 4-epimerase (Xu4E). Promiscuous activity of Xu4E, a monosaccharide C4-epimerase, was discovered for the first time. Directed evolution of Xu4E enabled to increase the catalytic function of C4-epimerization on D-xylulose as a substrate by more than 29-fold from the wild-type enzyme. Together, these results demonstrate that the in vitro synthetic biosystem as a feasible biomanufacturing platform has great engineering, and can be used to convert renewable biomass resources to a spectrum of marketable products and renewable energy.
As future efforts are addressed to overcome remaining challenges, for example, decreasing enzyme production costs, prolonging enzyme lifetime, engineering biomimetic coenzymes to replace natural coenzymes, and so on. This in vitro synthetic biology platform would become a cornerstone technology for biorefinery industries and advanced biomanufacturing (Biomanufacturing 4.0).Ph. D.
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Erik, Johansson. "Molecular Interactions in Thin Films of Biopolymers, Colloids and Synthetic Polyelectrolytes." Doctoral thesis, KTH, Fiberteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-41023.
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The development of the layer-by-layer (LbL) technique has turned out to be an efficient way to physically modify the surface properties of different materials, for example to improve the adhesive interactions between fibers in paper. The main objective of the work described in this thesis was to obtain fundamental data concerning the adhesive properties of wood biopolymers and LbL films, including the mechanical properties of the thin films, in order to shed light on the molecular mechanisms responsible for the adhesion between these materials. LbLs constructed from poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA), starch containing LbL films, and LbL films containing nanofibrillated cellulose (NFC) were studied with respect to their adhesive and mechanical properties. The LbL formation was studied using a combination of stagnation point adsorption reflectometry (SPAR) and quartz crystal microbalance with dissipation (QCM-D) and the adhesive properties of the different LbL films were studied in water using atomic force microscopy (AFM) colloidal probe measurements and under ambient conditions using the Johnson-Kendall-Roberts (JKR) approach. Finally the mechanical properties were investigated by mechanical buckling and the recently developed SIEBIMM technique (strain-induced elastic buckling instability for mechanical measurements). From colloidal probe AFM measurements of the wet adhesive properties of surfaces treated with PAH/PAA it was concluded that the development of strong adhesive joints is very dependent on the mobility of the polyelectrolytes and interdiffusion across the interface between the LbL treated surfaces to allow for polymer entanglements. Starch is a renewable, cost-efficient biopolymer that is already widely used in papermaking which makes it an interesting candidate for the formation of LbL films in practical systems. It was shown, using SPAR and QCM-D, that LbL films can be successfully constructed from cationic and anionic starches on silicon dioxide and on polydimethylsiloxane (PDMS) substrates. Colloidal probe AFM measurements showed that starch LbL treatment have potential for increasing the adhesive interaction between solid substrates to levels beyond those that can be reached by a single layer of cationic starch. Furthermore, it was shown by SIEBIMM measurements that the elastic properties of starch-containing LbL films can be tailored using different nanoparticles in combination with starch. LbL films containing cellulose I nanofibrils were constructed using anionic NFC in combination with cationic NFC and poly(ethylene imine) (PEI) respectively. These NFC films were used as cellulose model surfaces and colloidal probe AFM was used to measure the adhesive interactions in water. Furthermore, PDMS caps were successfully coated by LbL films containing NFC which enabled the first known JKR adhesion measurements between cellulose/cellulose, cellulose/lignin and cellulose/glucomannan. The measured adhesion and adhesion hysteresis were similar for all three systems indicating that there are no profound differences in the interaction between different wood biopolymers. Finally, the elastic properties of PEI/NFC LbL films were investigated using SIEBIMM and it was shown that the stiffness of the films was highly dependent on the relative humidity.QC 20110923
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Yam, Elodie. "Low molecular weight synthetic colloid fluids, 6% hydroxyethyl starch 130/0.4 and 4% succinylated gelatine, interfere with refractometric tests of total protein concentration and urine specific gravity." Thesis, Yam, Elodie (2018) Low molecular weight synthetic colloid fluids, 6% hydroxyethyl starch 130/0.4 and 4% succinylated gelatine, interfere with refractometric tests of total protein concentration and urine specific gravity. Masters by Research thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/46176/.
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Synthetic colloids used to treat shock, including 6% hydroxyethyl starch 130/0.4 (HES) and 4% succinylated gelatine (GELO), may interfere with refractometry due to large colloid molecules within the solution. This study aimed to assess the effects of these fluids on refractometric total plasma protein concentration (TPPr) and urine specific gravity (USG), using an in vitro (TPPr only) and an in vivo dog model. In the in vitro study, plasma samples from 10 greyhounds were diluted with 0.9% sodium chloride (NaCl), HES and GELO in ratios of plasma: fluid, 9:1, 8:2, 7:3, 6:4, 5:5. TPPr was compared to total plasma protein measured by the biuret assay (TPPb) at these dilutions. As the volume of colloid fluid increased, magnitude of over-estimation of TPPb (NaCl) by TPPr (HES and GELO), and TPPb (GELO) also increased. In the in vivo model, 18 anaesthetised greyhounds were subjected to haemorrhagic shock for 60 minutes, followed by either 80 mL/kg of Plasmalyte-148 (CRYST), or 20 mL/kg of HES or GELO (n=6 per group) given IV over 20 minutes. TPPr and TPPb were measured before haemorrhage (Baseline), at end of shock (Shock), after completion of fluid (T20), then 40 minutes (T60), 100 minutes (T120) and 160 minutes (T180) later. USG and urine osmolality (UOsm) were measured at all time points except T20. Bias and 95% limits of agreement (LOA) for TPPr vs TPPb, measured UOsm (mUOsm) vs estimated UOsm (eUOsm) from USG were calculated. Peak bias (TPP) for HES (T20) was 1.622 g/dL (95% LOA 1.291−1.953 g/dL) and for GELO (T180) was 0.577 g/dL (95% LOA 0.207−0.947 g/dL). Peak bias (UOsm) for HES (T60) was 2995 mOsm/L (95% LOA 2032−3958 mOsm/L) and for GELO (T120) was 2465 mOsm/L (95% LOA 940−3990 mOsm/L). Our research shows that HES and GELO interfere with refractometric tests and refractometry should not be used within 3 hours of bolus synthetic colloid administration.
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Stauch, Claudia [Verfasser], Karl Sebastian [Gutachter] Mandel, Robert [Gutachter] Luxenhofer, and Klaus [Gutachter] Müller-Buschbaum. "Synthese und Charakterisierung nanostrukturierter Mikropartikel mit einstellbarem Zerfallsverhalten als Additive für Elastomerkomposite / Claudia Stauch ; Gutachter: Karl Sebastian Mandel, Robert Luxenhofer, Klaus Müller-Buschbaum." Würzburg : Universität Würzburg, 2019. http://d-nb.info/1180982266/34.
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Bernardo, Angela Silva Di. "Influência das condições de aplicação de polímeros catiônicos na eficiência da floculação." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-02122015-112130/.
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Tendo em vista que os amidos (catiônicos ou não) não são nocivos a saúde do ser humano, uma vez que são utilizados na indústria de alimentos, e observando-se a potencialidade do seu uso como auxiliares de floculação, foi proposto o presente trabalho. Consiste na realização de ensaios de coagulação (com sulfato alumínio), floculação e sedimentação em equipamento de reatores estáticos, objetivando verificar a influência do gradiente de velocidade e do tempo de agitação na floculação com polímero sintético catiônico e amidos de milho e mandioca catiônicos. Concluiu-se que as condições de aplicação exercem influência na eficiência de remoção de turbidez e cor aparente, sendo que cada polímero estudado apresentou uma condição ótima específica. Em todos os ensaios realizados, o amido de mandioca catiônico foi o mais eficiente, indicando que os amidos catiônicos podem ser substitutos em potencial dos polímeros sintéticos no tratamento de águas de abastecimento, quando utilizados como auxiliares de floculação.This present work was based on the fact that native and cationic starches are not harmful to man\'s health, since they have been largely used in food processing industries, and that they may be potentially used as flocculation aids in water treatment. Jar Test assays were performed, including coagulation with aluminum sulphate, flocculation and sedimentation, aiming to study the influence of the velocity gradient and mixing time on flocculation, using a cationic synthetic polymer and cationic com and manioc starches as aids. In the main, it was concluded that the conditions under which the polymers were applied, affect the efficiency of turbidity and color removals and that each polymer studied presented an specific optimum condition. It was also observed that manioc cationic starch resulted more effective than the others polymers studied, when used as flocculation aids.
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Yang, Chongqing, Dongqing Wu, Wuxue Zhao, Weizhen Ye, Zhixiao Xu, Fan Zhang, and Xinliang Feng. "Anion-induced self-assembly of positively charged polycyclic aromatic hydrocarbons towards nanostructures with controllable two-dimensional morphologies." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224930.
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A controllable self-assembly strategy of positively charged polycyclic aromatic hydrocarbons (PCPAH) towards the formation of rectangle sheets and ribbon-like nanostructures has been achieved by choosing divalent anions with different sizes. In contrast, only rod-like nanostructures are obtained from PCPAH with univalent anions. It is revealed that the divalent anions play a key role in guiding the packing of PCPAH, which provides an unprecedented route to fabricate two-dimensional nanostructures.
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Yang, Chongqing, Dongqing Wu, Wuxue Zhao, Weizhen Ye, Zhixiao Xu, Fan Zhang, and Xinliang Feng. "Anion-induced self-assembly of positively charged polycyclic aromatic hydrocarbons towards nanostructures with controllable two-dimensional morphologies." Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30330.
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A controllable self-assembly strategy of positively charged polycyclic aromatic hydrocarbons (PCPAH) towards the formation of rectangle sheets and ribbon-like nanostructures has been achieved by choosing divalent anions with different sizes. In contrast, only rod-like nanostructures are obtained from PCPAH with univalent anions. It is revealed that the divalent anions play a key role in guiding the packing of PCPAH, which provides an unprecedented route to fabricate two-dimensional nanostructures.
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Cheviron, Perrine. "Nanostructuration de films nanocomposites amidon / argent et amidon / argent / montmorillonites par procédé de « chimie verte » : influence des voies de génération des nanoparticules métalliques sur la structure et les propriétés de transport." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10047/document.
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Des films nanocomposites amidon / argent ont été préparés par deux voies de génération vertes de nanoparticules d'argent. La première voie, dite ex situ, consiste à préparer tout d'abord une solution colloïdale d'argent qui est ensuite redispersée dans une matrice amidon plastifiée glycérol. Les nanoparticules d'argent colloïdales sont synthétisées en solution aqueuse par réduction du nitrate d'argent par du glucose en présence d'amidon stabilisant. La seconde voie, dite in situ, consiste à disperser le nitrate d'argent dans le film amidon plastifié et le réduire directement dans le film par traitement thermique en présence ou non de réducteur. L'influence du taux de glucose réducteur, du temps de synthèse et de la température a été étudiée en termes de taille, distribution de taille et dispersion des nanoparticules d'argent dans les films nanocomposites ex situ et in situ. Tout en gardant des paramètres de procédé comparables, les deux voies de nanostructuration des films amidon/argent ont également été comparées en termes de structure, de propriétés thermiques et de transport. Enfin, l'incorporation de charges montmorillonites a également été étudiée dans les deux voies de génération des nanoparticules métalliques. L'ensemble des travaux a permis de valider les deux voies de génération vertes menant à des nanoparticules d'argent dispersées de manière homogène et de tailles moyennes inférieures à 30 nm. La voie in situ à 85°C se distingue par des nanoparticules d'argent cristallines et de très petites tailles (inférieures à 10 nm) avec une interface amidon/argent cohésive particulière qui permettent d'améliorer les propriétés barrières aux gaz et à l'eau avec une diminution de perméabilité observée jusqu'à 90%The present work reports a strategy involving the preparation of silver nanoparticles in a biodegradable polymer stemming from either an ex situ or an in situ method, using in both cases a completely green chemistry process. The influence of the reducing agent concentration and the silver nanoparticles generation route is investigated on the structure, the morphology and the properties of the nanocomposite films. In both routes, silver nanoparticles with a diameter below 30 nm were highlighted in the nanocomposite films. For all nanocomposite films, no modification on the crystalline structure of the starch matrix is observed in the presence of silver. The in situ generation route allowed to obtain the smallest silver nanoparticles with a diameter below 10 nm. Crystalline silver nanoparticles were obtained only from the in situ generation route at the temperature of 85°C. The introduction of montmorillonites in both generation routes was also studied. The decrease of the water sorption and the improvement of water and oxygen barrier properties were found to be not dependent on the reducing agent concentration but mainly on the presence of the crystalline structure of the silver nanoparticles. Thus, significant enhancement of the barrier properties were finally obtained for the in situ nanocomposite films thanks to an efficient interaction between the crystalline silver nanoparticles and the starch matrix
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Higgins, Jody Estelle. "The role of starch phosphorylase in cereal starch synthesis." Phd thesis, 2005. http://hdl.handle.net/1885/151653.
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Luo, Jixun. "Understanding the impact of starch synthase IIa on starch structure and function in cereal endosperm." Phd thesis, 2014. http://hdl.handle.net/1885/156138.
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Starch synthase IIa (SSIIa) is one of the major starch biosynthetic enzymes in starch biosynthesis process in cereal endosperms. It catalyzes the synthesis of intermediate chains in amylopectin of the grain starch. During starch deposition it interacts with other starch synthases (SSs) and starch branching enzymes (SBEs) to form functional protein complexes. The defective SSIIa mutants of cereals in common showed significantly altered amylopectin chain length distribution (CLD), and pleiotropic effects inside the starch granules with reduced amount of starch granule bound proteins (GBPs). However, these effects observed in the mutants varied at different degrees in different cereals. In this study, SSIIa was chosen to investigate its impact on starch structure, functional properties and regulatory role in starch biosynthesis in the endosperms of barley, wheat and rice. The rice ssIIa mutants with japonica type SSIIa were obtained from a population of recombinant inbred lines (RILs) derived from an IR64 and Nipponbare hybrid. In addition, five other starch biosynthetic genes, Wx, SSI, SBEI, SBEIIa and SBEIIb, which could have potential allelic effects on starch structure and functional properties, were also investigated to understand the allelic recombination effect. Defective SSIIa hybrid populations of barley and wheat were used for screening ssIIa mutants for the quantitatively comparative analysis. The comparison was done at three levels: gene transcription, posttranslational regulation and starch structure. The allelic effect study showed that SSIIa and Wx had the most significant influences on starch structure and functional properties. The impact of Wxi and SSIIaj on starch functional properties was similar, having lower peak viscosity (PV) and breakdown (BD), higher final viscosity (FV) and setback (SB), lower amylopectin gelatinization temperatures (GTs) and higher amylose-lipid complex dissociation enthalpy compared with Wxj and SSIIai, respectively. Only SSIIaj haplotype produced a novel amylopectin structure with the most pronounced alteration in short chain and intermediate chain fractions. At similar levels of starch AC, the ratio of short chain/ short plus intermediate chain fraction percentage in debranched starch was negatively correlated to PV, BD and GTs. The remarkable changes in starch structure were also related with the abundance of GBPs in starch granules. SSI, SBEI, SBEIIa and SBEIIb had only limited allelic effects on starch structure and functional properties compared with SSIIa and Wx. The comparison analysis in the three cereals indicated that the total amount of SSI, SBEIIa and SBEIIb synthesized in the endosperm of the three ssIIa mutants was not affected by the SSIIa defection. The pleiotropic effects on GBPs in starch granules were due to the changes in protein partitions between amyloplast stroma and starch granules regulated by SSIIa. The order of changes (HvssIIa > TassIIa > OsssIIa) in the ssIIa mutants compared with corresponding wildtypes were consistent in the starch AC, amylopectin CLD, and starch biosynthetic enzyme partitions. These changes were related with the variation of SSI, SSIIa, SBEIIa and SBEIIb abundance inside starch granules and/or the dosage of SSIIa gene. The various SSIIa abundances inside starch granules were due to the differences in SSIIa mutations in different cereal mutants.
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Chen, Chen-Kai, and 沈聖凱. "Utilization of starch for polyhydroxyalkanoates synthesis by microorganism." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39413061250603328422.
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碩士元智大學
生物科技暨生物資訊研究所
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The aim of this study is to evaluate the utilization of starch as sole carbon source in the process of producing polyhydroxylalkanoates (PHAs) by microorganisms. The main purpose was to lowering the production cost of PHAs. We isolated numerous microorganisms from different environment able to accumulate various types of PHAs. We screened the ability for producing amylase by these isolates and evaluated those amylase-producing strains for their ability to utilize starch as sole carbon source. Among them, strain KC013 showed the ability of producing alpha-amylase and be able to utilize starch as sole carbon source. KC013 was cultivated with soluble starch as sole carbon source and PHAs produced under this growth condition was analyzed by Fourier-Transform Infracted spectrometer (FT-IR) and gas chromatography (GC). The results showed strain KC013 (identified as an Aeromonas sp.), along with some other isolates, were able to utilize starch to produce PHAs.
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劉書劍. "Synthesis and characterization of starch-acrylamide graft copolymer." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/57897178374686733689.
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Tsai, Huang-Lung, and 蔡皇龍. "Starch synthesis in Arabidopsis is achieved by spatial co-transcription of core starch metabolism genes." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/25469928569497455103.
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博士國防醫學院
生命科學研究所
98
Starch synthesis and degradation require the participation of many enzymes, occur in both photosynthetic and non-photosynthetic tissues, and are subject to environmental and developmental regulation. We examine the distribution of starch in vegetative tissues of Arabidopsis thaliana. We observe that starch is accumulated ubiquitously in plastids of cells aboveground (e.g., epidermal, mesophyll and vascular cells) and in root tips cells but not in root proper cells. We also identify cells that can synthesize starch heterotrophically in albino mutants. We hypothesize that exogenous Glc-6-P source can be utilized in epidermal cells, vascular bundles and root tips for heterotrophic starch synthesis. From the distribution pattern of starch accumulated in leaves indicates that starch synthesis in leaves is regulated by developmental stage and light. To find out whether expression of starch metabolism genes are correlated with starch accumulation, we examine the distribution of starch and spatial expression of five synthesis genes, i.e., PGI1 (PHOSPHOGLUCOSE ISOMERASE1), PGM1 (PHOSPHOGLUCOSE MUTASE1), APS1 (ADPG PYROPHOSPHORYLASE SMALL SUBUNIT1), APL1 (ADPG PYROPHOSPHORYLASE LARGE SUBUNIT1) and SS1 (STARCH SYNTHASE1), in Arabidopsis seedlings. Except PGI1, the enzyme activities and transcripts of other genes are detected in cells with starch, but are absent in root proper cells. PGI1 gene is expressed ubiquitously, even in root proper cells which have no starch accumulation. The expression of PGI1 in root proper cells suggests that PGI may play roles other than starch synthesis in root propers. Expression of gene promoter--glucuronidase fusion constructs in transgenic seedlings shows that starch synthesis genes are transcriptionally active in cells with starch synthesis and are inactive in root proper cells except the plastidial phosphoglucose isomerase. Suprisingly, APL1 encoding the dominant large subunit of APGase (ADPG pyrophosphorylase) in leaves, is not expressed and not required for starch synthesis in root cap cells. Our data indicate that there are differential regulations among starch synthesis genes, and spatially distinct routes are used by starch synthesis machinery in plant tissues. Expression profile analysis reveals that starch metabolism genes can be clustered into two sets based on their tissue-specific expression patterns. To investigate the regulatory elements for starch metabolism genes, we generate transgenic plants carrying serial deletion of APS1 promoter-GUS constructs. The expression pattern of GUS reporter in these transgenic plants indicates that the 5’ distal region of APS1 promoter contains a fragment which may be responsible for the repression of APS1 promoter activity in lateral root bases. Detailed mutation analysis of this region, we identify a conserved motif, which is essential for the repression, present in many co-expressed starch metabolism genes. Starch distribution and expression pattern of core starch synthesis genes are common in Arabidopsis and rice (Oryza sativa), suggesting that the regulatory mechanism for starch metabolism genes may be conserved evolutionarily. We conclude that starch synthesis in Arabidopsis is achieved by spatial co-expression of core starch metabolism genes regulated by their promoter activities and is fine-tuned by cell specific endogenous and environmental controls.
47
Liu, H. P., and 劉小萍. "Studies on the Synthesis and Properties of Starch-g-Poly(vinyl acetate) and Starch-g-Poly(vinyl alcohol) Copolymers." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/84478959055659517447.
Full textAbstract:
碩士國立臺灣大學
化學工程學研究所
89
Cerium ammonium nitrate (CAN) and potassium persulfate (KPS) were used to initiate the polymerization of vinyl acetate (VAc) monomer onto corn starch and soluble starch respectively to produce starch-graft-PVAc copolymers, and starch-graft-PVOH copolymers with an additional alcoholysis treatment. The main aspects of this research were the analysis of resulting copolymers including the elucidation of micro-structure with the morphology observations through transmission electron microscope (TEM) and scanning electron microscope (SEM), and product identifications based on Fourier transform infrared (FTIR) spectra. Meanwhile, the reaction kinetics, such as the conversion, the grafting ratio and grafting efficiency, were monitored throughout the experiments. Enzymatic degradation and cell culture were also carried out to evaluate the biodegradability and biocompatibility for PVOH grafted copolymers. Due to the basic differences of characteristics in types of starch and initiating mechanisms of initiators, the grafted products were quite different in terms of aforementioned characterizations. It was found that the monomer conversion, grafting ratio and grafting efficiency were higher for soluble starch system. The conversion and grafting ratio were increased with increasing monomer ratio. Not only the extracted-PVAc, but also the grafted-PVAc, molecular weights of which attained were higher for KPS systems and soluble starch systems. According to the observation of TEM and SEM, particles are generally smaller and more uniform in sizes for CAN than for KPS system. In addition, a flexible starch-PVOH film capable of enzymatic degradation and cell culture was obtained. The weight loss was higher for a corn starch-PVOH film, and the test results of fibroblast culture showed positive effects only for KPS system.
48
Kolbe, Anna [Verfasser]. "Redox-regulation of starch and lipid synthesis in leaves / Anna Kolbe." 2005. http://d-nb.info/978968182/34.
Full text
49
"Proteomic study on the starch synthesis and regulation in developing hybrid rice seeds." 2006. http://library.cuhk.edu.hk/record=b5892918.
Full textAbstract:
Long Xiaohang.Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references (leaves 132-155).
Abstracts in English and Chinese.
Thesis/Assessment Committee --- p.I
Statement from Author --- p.II
Acknowledgements --- p.III
Abstract --- p.V
摘要 --- p.VII
Table of Contents --- p.IX
List of Tables --- p.XV
List of Figures --- p.XVI
List of Abbreviations --- p.XVIII
Chapter Chapter 1 --- General Introduction and Literature Review --- p.1
Chapter 1.1 --- General introduction --- p.1
Chapter 1.2 --- Literature review --- p.5
Chapter 1.2.1 --- Rice --- p.5
Chapter 1.2.1.1 --- Classification of rice --- p.5
Chapter 1.2.1.2 --- Rice grain quality --- p.5
Chapter 1.2.2 --- Overview of current information on the starch biosynthesis and regulation during seed development --- p.7
Chapter 1.2.2.1 --- Starch property --- p.7
Chapter 1.2.2.1.1 --- Structure of rice starch granules --- p.7
Chapter 1.2.2.1.2 --- Properties of rice starch --- p.7
Chapter 1.2.2.2 --- Starch synthesis related proteins --- p.8
Chapter 1.2.2.2.1 --- The formation of ADP-glucose through AGPase --- p.10
Chapter 1.2.2.2.2 --- The synthesis of starch by starch synthases --- p.10
Chapter 1.2.2.2.2.1 --- Amylose biosynthesis --- p.10
Chapter 1.2.2.2.2.2 --- Amylopectin biosynthesis --- p.11
Chapter 1.2.2.2.3 --- Branching of the glucan chain by starch branching enzymes --- p.12
Chapter 1.2.2.2.4 --- The role of debranching enzymes in polymer synthesis --- p.13
Chapter 1.2.2.2.5 --- Starch degradation in plastids --- p.13
Chapter 1.2.2.2.6 --- Other enzymes involved in starch synthesis pathway --- p.13
Chapter 1.2.2.3 --- Starch biosynthesis regulation --- p.14
Chapter 1.2.2.3.1 --- Developmental regulation --- p.14
Chapter 1.2.2.3.2. --- Diurnal regulation --- p.15
Chapter 1.2.2.3.3 --- 3-PGA/Pi regulation --- p.16
Chapter 1.2.2.3.4. --- Sugar signaling --- p.17
Chapter 1.2.2.3.5. --- Hormonal signaling --- p.18
Chapter 1.2.2.3.6 --- Post translational modification regulation --- p.18
Chapter 1.2.2.3.6.1 --- Post translational redox modulation --- p.18
Chapter 1.2.2.3.6.2 --- Protein phosphorylation --- p.19
Chapter 1.2.2.4 --- Rice grain quality improvement by genetic engineering --- p.20
Chapter 1.2.2.4.1 --- Cooking and eating quality improvement --- p.20
Chapter 1.2.2.4.1.1 --- Manipulation of starch content --- p.20
Chapter 1.2.2.4.1.2 --- Manipulation of amylose/ amylopectin ratio --- p.20
Chapter 1.2.2.4.2 --- Other targets for manipulating starch quality and quantity --- p.21
Chapter 1.2.3 --- Proteomics --- p.23
Chapter 1.2.3.1 --- General introduction --- p.23
Chapter 1.2.3.2 --- Current technologies of proteomics --- p.25
Chapter 1.2.3.2.1 --- Protein separation by 2D or non-2D method --- p.25
Chapter 1.2.3.2.2 --- Protein visualization --- p.26
Chapter 1.2.3.2.3 --- Computer-assisted image analysis --- p.27
Chapter 1.2.3.2.4 --- Protein identification by mass spectrometry --- p.28
Chapter 1.2.3.2.5 --- Database search --- p.28
Chapter 1.2.3.2.5.1 --- Database searching software --- p.29
Chapter 1.2.3.2.5.2 --- Protein sequence database --- p.29
Chapter 1.2.3.2.5.3 --- Evaluating database hits --- p.30
Chapter 1.2.3.2.6 --- Bioinformatics involved in proteomics --- p.31
Chapter 1.2.3.2.7 --- Post translational modification --- p.32
Chapter 1.2.3.2.7.1 --- Glycosylation --- p.32
Chapter 1.2.3.2.7.1.1 --- N-linked glycosylation --- p.33
Chapter 1.2.3.2.7.1.2 --- O-linked glycosylation --- p.33
Chapter 1.2.3.2.7.2 --- Phosphorylation --- p.33
Chapter 1.2.3.2.7.3 --- Strategies for studying PTMs --- p.34
Chapter 1.2.3.2.8 --- Other aspects of proteomics --- p.36
Chapter 1.2.3.2.8.1 --- 2D DIGE --- p.36
Chapter 1.2.3.2.8.2 --- LC/LC-MS/MS --- p.36
Chapter 1.2.3.2.8.2.1 --- MudPIT --- p.36
Chapter 1.2.3.2.8.2.2 --- ICAT --- p.37
Chapter 1.2.3.3 --- Plant proteomics --- p.37
Chapter 1.2.3.3.1 --- Proteome analysis of plant tissues and organs --- p.38
Chapter 1.2.3.3.2 --- Plant organelle proteomics --- p.39
Chapter 1.2.3.3.3 --- Post translational modifications in plant --- p.41
Chapter 1.2.3.4 --- Recent progress in rice proteomics --- p.42
Chapter 1.2.3.4.1 --- General introduction of rice proteomics --- p.42
Chapter 1.2.3.4.2 --- Rice proteome database construction --- p.43
Chapter 1.2.3.4.3 --- Comparative proteomics --- p.43
Chapter 1.2.3.4.4 --- Post translational modification study of rice proteome --- p.44
Chapter Chapter 2 --- Materials and methods --- p.45
Chapter 2.1 --- Materials --- p.45
Chapter 2.1.1 --- Plant materials --- p.45
Chapter 2.1.2 --- Chemical reagents and commercial kits --- p.46
Chapter 2.1.3 --- Instruments --- p.46
Chapter 2.1.4 --- Software --- p.46
Chapter 2.2 --- Methods --- p.47
Chapter 2.2.1 --- Fractionation of amyloplast and amyloplast membrane proteins --- p.47
Chapter 2.2.2 --- Marker enzyme assays --- p.47
Chapter 2.2.3 --- 2D gel electrophoresis --- p.48
Chapter 2.2.4 --- Silver staining of 2D gel --- p.49
Chapter 2.2.5 --- In-gel digestion of protein spots --- p.49
Chapter 2.2.6 --- Desalination of the digested sample with ZipTip --- p.49
Chapter 2.2.7 --- Protein identification by mass spectrometry and database searching --- p.50
Chapter 2.2.8 --- Image and data analysis --- p.50
Chapter 2.2.9 --- Extraction of starch granule associated proteins --- p.51
Chapter 2.2.10 --- Western blot analysis --- p.51
Chapter 2.2.11 --- Sample preparation for N terminal sequencing --- p.51
Chapter 2.2.12 --- Phosphorylation and glycosylation assays --- p.52
Chapter Chapter 3 --- Results --- p.53
Chapter 3.1 --- Protein identification by ID and 2D PAGE --- p.53
Chapter 3.1.1 --- Isolation and purification of amyloplasts from rice seeds --- p.53
Chapter 3.1.2 --- Identification of amyloplast and amyloplast membrane proteins by MS/MS --- p.54
Chapter 3.1.2.1 --- Sample preparation --- p.54
Chapter 3.1.2.2 --- 2D and ID gel electrophoresis --- p.55
Chapter 3.1.2.3 --- Protein identification by MS and MS/MS --- p.56
Chapter 3.1.3 --- Functional classification of identified proteins --- p.69
Chapter 3.1.3.1 --- Metabolism proteins --- p.71
Chapter 3.1.3.2 --- Non starch synthesis metabolism proteins --- p.73
Chapter 3.1.3.3 --- Protein destination --- p.73
Chapter 3.1.3.4 --- Proteins with other functions --- p.74
Chapter 3.1.4 --- Cross-correlation of experimental and calculated Mw of proteins --- p.74
Chapter 3.1.5 --- Granule bound starch synthase (GBSS) --- p.75
Chapter 3.1.5 --- N-terminal sequencing --- p.77
Chapter 3.2 --- Protein profiling --- p.80
Chapter 3.2.1 --- Seed collection and stages chosen --- p.80
Chapter 3.2.2 --- The proteomic profiles of rice amyloplasts at different developing stages --- p.81
Chapter 3.2.4 --- Comparing the proteome of three rice lines --- p.85
Chapter 3.2.4.1 --- Spot number analysis --- p.85
Chapter 3.2.4.2 --- Functional distribution analysis --- p.86
Chapter 3.2.4.3 --- Protein amount analysis --- p.87
Chapter 3.2.5 --- Comparison of expression pattern: cluster analysis (SOM) --- p.88
Chapter 3.2.5.1 --- Cluster analysis of rice amyloplast proteome --- p.88
Chapter 3.2.5.2 --- Three major categories of rice amyloplast proteome expression patterns --- p.91
Chapter 3.2.6 --- Scatter plots analysis --- p.94
Chapter 3.2.7 --- Comparison of changes in proteins related to starch synthesis --- p.96
Chapter 3.2.7.1 --- GBSS --- p.96
Chapter 3.2.7.2 --- AGPase --- p.98
Chapter 3.2.7.3 --- SSS --- p.98
Chapter 3.2.7.4 --- SBE --- p.98
Chapter 3.2.7.5 --- SP --- p.98
Chapter 3.3 --- Study on protein post translational modifications --- p.102
Chapter 3.3.1 --- Post translational modifications that potentially regulate starch synthesis --- p.102
Chapter 3.3.2 --- Post translational modifications at different developing stages --- p.104
Chapter 3.3.2.1 --- Profiling of post translational modifications of rice amyloplast proteome --- p.104
Chapter 3.3.2.2 --- Starch synthesis related proteins --- p.106
Chapter 3.3.2.2.1 --- GBSS --- p.106
Chapter 3.3.2.2.2 --- SSS --- p.108
Chapter Chapter 4 --- Discussion --- p.111
Chapter 4.1 --- Methodology --- p.111
Chapter 4.1.1 --- Amyloplast isolation --- p.111
Chapter 4.1.2 --- Protein extraction from amyloplasts --- p.111
Chapter 4.1.3 --- Protein identification by PMF and MS/MS --- p.112
Chapter 4.1.4 --- Methods used to study protein expression patterns --- p.113
Chapter 4.1.5 --- New methods introduced to study post translational modifications --- p.114
Chapter 4.2 --- Characteristics of rice amyloplast proteins --- p.115
Chapter 4.2.1 --- Amyloplast proteins associated with starch granules --- p.116
Chapter 4.2.2 --- Most proteins in amyloplast proteome contain the transit peptide --- p.116
Chapter 4.2.3 --- Multiple isoforms of starch synthesis related proteins --- p.117
Chapter 4.2.3.1 --- Multiple spots of GBSS --- p.118
Chapter 4.2.4 --- Expression patterns of amyloplast proteome --- p.120
Chapter 4.2.5 --- Post translational modifications potentially regulate starch synthesis --- p.122
Chapter 4.3 --- Other characteristic aspects of amyloplast proteome --- p.123
Chapter 4.3.1 --- Comparison between the rice and wheat amyloplast proteomes --- p.123
Chapter 4.3.2 --- Proteomic comparisons among the three rice lines --- p.124
Chapter 4.3.3 --- Comparison of starch synthesis enzymes at protein and transcript levels --- p.124
Chapter 4.3.4 --- Comparison of the starch synthesis related proteins among the three rice lines --- p.126
Chapter 4.4 --- Limitations of proteomic approach in directly answering the question on how to improve eating and cooling quality --- p.126
Chapter Chapter 5 --- Conclusion --- p.128
Chapter Chapter 6 --- Future perspectives --- p.130
References --- p.132
50
Wu, Sih-Pei, and 吳思佩. "Association analysis of sorghum quality and their starch synthesis genes SSIIa、Wx、Ae1." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/27022778055554058426.
Full textAbstract:
碩士國立臺灣大學
園藝學研究所
100
Sorghum is rich in starch content, the starch quality contributes to its nutritional value and processing attributes tremendously. In this study, seven varieties of soghum were collected for analysis in their starch content, amylose content, pasting properties, thousand grain weight, and grain size. To identify the correlation of gene variation and the phenotype in starch content, genes including soluble starch synthases (SSIIa), granule-bound starch synthase (Wx) and starch branching enzyme (Ae1) were chosen for association analysis using statistical software. A total of 9 polymorphisms in SSIIa and 7 polymorphisms in Wx were identified, which were greatly associated with starch pasting properties. A total of 29 polymorphisms in two fragments of Ae1 were identified. Single nucleotide polymorphisms(SNP) and InDel in Ae1 were found associated with gelatinization temperature, which with a difference of 9.4℃ in gelatinization temperature. One SNP in non-coding region of Ae1 were found associated with amylase content (p<0.05), inferred deletion of a adenine base would cause a decrease in non-branching starch. The polymorphism we identified in this study may provide a genetic explanation to variation in sorghum starch properties.