Дисертації з теми "Acidi succinici"
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Venneri, Cesare Daniele. "Sintesi stereoselettiva mediata da enzimi di analoghi lineari e ciclici dell'acido Ÿ- amminobutirrico." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3517.
Повний текст джерелаE’ stata sviluppata una sintesi enantioselettiva facile e rapida di una serie di analoghi del GABA beta-sostituiti e beta,beta’-disostituiti potenzialmente utili, a partire da precursori gamma-nitro esterei racemi facilmente disponibili, attraverso la loro risoluzione cinetica enzimatica. L'applicazione della procedura descritta al substrato che reca in posizione beta il raggruppamento isobutilico consente di ottenere il composto terapeuticamente utile (S)-(+)-Pregabalina e la sua controparte enantiomerica; la medesima strategia sintetica applicata al substrato beta,beta’-disostituito con i gruppi metile e isobutile conduce all’analogo tetrasostituito della stessa Pregabalina, mentre il substrato recante in beta,beta’ il gruppo 3-metilcicloesile permette l’ottenimento di un analogo chirale della Gabapentina (Neurontin®) e del suo enantiomero. L’interesse verso la sintesi di gamma-amminoacidi beta,beta’-sostituiti risiede non solo nella potenziale attività biologica dei composti target, analoghi chirali della Gabapentina, ma è anche in relazione al problema sintetico connesso con l’ottenimento di composti chirali in cui l’atomo di carbonio asimmetrico è quaternario. I risultati ottenuti sono di notevole interesse anche alla luce della nota riluttanza delle comuni idrolasi a riconoscere e trasformare substrati in cui il centro chirale adiacente alla funzione idrolizzabile è completamente sostituito. La medesima procedura rappresenta inoltre una strategia sintetica alternativa per acidi 2-alchilsuccinici otticamente attivi, che possono essere così ottenuti in condizioni relativamente blande. Infatti la trasformazione di un nitrocomposto primario in un acido carbossilico, nota come reazione di Victor Meyer, richiede condizioni drastiche, cioè trattamento a riflusso con acidi minerali, oppure laboriose procedure di sintesi. Gli acidi succinici, oltre a manifestare varie attività a livello biologico, sono utili intermedi sintetici per importanti building blocks omochirali come beta-lattami, beta- e gamma-lattoni, succinimidi, anidridi succiniche. Nell’ambito della sintesi degli analoghi del GABA beta,beta’-sostituiti, inoltre, parallelamente al lavoro con gli enzimi è stata sviluppata un’addizione coniugata diretta e altamente enantioselettiva di un nitroalcano ad un’aldeide alfa,beta-insatura usando difenilprolinol silil etere come organocatalizzatore, per ottenere un intermedio prontamente convertito nell’amminoacido target. Questa concisa, pratica ed efficiente procedura sintetica si ritiene possa trovare ampia applicabilità nella sintesi stereoselettiva di altri composti recanti un carbonio quaternario chirale, di difficile ottenimento, e, in particolare, di altri gamma-amminoacidi beta,beta-dialchilati enantiopuri di interesse chimico e farmaceutico. Si presenta infine un’efficiente sintesi dell’acido 2-carbossi-3-pirrolidinacetico, gamma-amminoacido conformazionalmente costretto e importante agonista del recettore NMDA (N-metil-D-aspartato) che costituisce lo scheletro degli acidi kainici, dotati, fra le varie azioni biologiche, di attività neuroeccitatoria. La strategia sintetica proposta conduce ad elevati eccessi enantiomerici e rese soddisfacenti.
XXII Ciclo
1981
De, Klerk Jean-Louis. "Succinic acid production by wine yeasts." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4228.
Повний текст джерелаENGLISH ABSTRACT: One of the most striking qualities of wine is its tart, sour taste. The sensory perception of sourness is mainly attributed to the presence of hydrogen ions (protons) at high concentrations. Large amounts of weak carboxylic acids (organic acids) are the main sources of these ions within wine. Once wine enters a person's mouth, the dissociable protons of the weak organic acids within wine are partially neutralized or, in other words, titrated by the saliva secreted inside one's mouth. This explains why the duration and intensity of a wine's sourness is related to its titratable acidity content. The sour taste of wine is usually considered refreshing and it helps balance wine flavour. In fact, wines become watery when its titratable acidity content is too low. After alcoholic fermentation, the titratable acidity of wine will usually be less than that of the grape juice from which was made due to ethanol-induced precipitation of potassium bitartrate crystals and partial consumption of malic acid by fermenting wine yeasts. Occasionally however, increases in titratable acidity are observed during alcoholic fermentation. If wine is produced from grape juice with optimum levels of titratable acidity, unforeseen increases in titratable acidity during alcoholic fermentation can be detrimental to the quality of the final product. Although the net production of malic acid by wine yeasts contributes to increases in titratable acidity seen during grape juice fermentations, the production of succinic acid is regarded as the primary contributor. In fact, succinic acid accounts for approximately 90% of the non-volatile acids produced during fermentation of grape juice. Between 0.5 and 1.5 g/L succinic acid is normally found in wine, but higher concentrations thereof (up to 3.0 g/L) have been detected within certain red wines. Acidity adjustments should preferably be carried out before the onset of alcoholic fermentation to allow better integration of the added compound(s) and to ensure that conditions during fermentation favour the quality and microbial stability of the final product. In doing so unfortunately, winemakers run the risk of ending up with wines that may taste too sour if they are unable to accurately predict and take into consideration the amount of succinic acid produced during alcoholic fermentation. Knowledge with regard to the factors involved in succinic acid's production by fermenting wine yeasts is therefore required in order to manage the titratable acidity of wines more accurately. Ever since Louis Pasteur first noticed succinic acid amongst the by-products of alcoholic fermentation, attempts have been made to determine the metabolic pathways and factors involved in its production by fermenting wine yeasts. Up until now however, it remains unclear why wines sometimes end up with exceptionally high levels of succinic acid. For these reasons it was decided to investigate the possible causes of very high succinic acid concentrations within wine. Due to complexity of grape juice's chemical composition and the problems associated with sterilizing grape juice, fermentation experiments were conducted within a chemically defined grape juice-like medium. Succinic acid production by nine different industrial wine yeast strains was studied under various conditions with regard to the nutrient status of the synthetic grape juice, temperature and availability of molecular oxygen during alcoholic fermentation. The amount of succinic acid produced during alcoholic fermentation was found to depend on the yeast strain, fermentation temperature and chemical composition of the synthetic grape juice. Out of the nine commercial yeast strains selected for this study, strain WE372 produced the largest amount of succinic acid in synthetic grape juice at 28°C. Strain WE372 produced significantly smaller amounts of acetic acid than the other yeast strains of this study and very little acetic acid at 28°C, which indicated that strain WE372 may have less acetaldehyde dehydroganase activity than the other yeast strains of this study under the conditions tested. The effect this has on NAD: NADH balance is the probable cause for its ability to form more glycerol, succinic and malic acid than the other strains. Results from our study show that succinic acid production is influenced primarily by the metabolizable fraction of YAN, which we termed metabolically available nitrogen (MAN). Succinic acid production by fermenting yeasts will be favoured by moderate to high fermentation temperatures (20°C to 28°C) in grape juice with a nicotinic acid and/ or nicotinamide deficiency, high sugar content (200 g/L to 240 g/L), moderate amounts of metabolically available nitrogen (300 ± 50 mg/L MAN), the presence of flavonoids and large supplies of unsaturated long-chain fatty acids. Even higher concentrations of succinic acid were produced when oxygen was made available to fermenting yeasts by aerating the fermenting grape juice. Fermentation temperatures below 18°C, too much metabolizable nitrogen (> 450 mg/L MAN), very high concentrations of fermentable sugar (> 240 g/L), lipid deficiencies and a lack of pantothenic acid, thiamine, biotin or pyridoxine will decrease the amount of succinic acid produced fermenting yeasts.
No Afrikaans summary available.
Andersson, Christian. "Succinic acid production using metabolically engineered Escherichia coli." Licentiate thesis, Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1757/2007/12/.
Повний текст джерелаBrown, Samantha Jayne. "Novel fluorinated succinic acid derivatives from HCFC-133a." Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396808.
Повний текст джерелаMaharaj, Karishma. "Continuous succinic acid fermentation using immobilised Actinobacillus succinogenes." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/40818.
Повний текст джерелаDissertation (MEng)--University of Pretoria, 2013.
gm2014
Chemical Engineering
unrestricted
Vlysidis, Anestis. "Sustainable biodiesel biorefineries for the green succinic acid production." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/sustainable-biodiesel-biorefineries-for-the-green-succinic-acid-production(03cedd62-6e30-4719-b9ff-e6776583b733).html.
Повний текст джерелаMokwatlo, Sekgetho Charles. "Analysis of succinic acid-producing biofilms of Actinobacillus succinogenes." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/76114.
Повний текст джерелаThesis (PhD)--University of Pretoria, 2020.
NRF
Chemical Engineering
PhD
Unrestricted
Andersson, Christian. "Biobased production of succinic acid by Escherichia coli fermentation /." Luleå : Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/2578562.
Повний текст джерелаAbou, Hamdan Marwa. "Hydrogenation of succinic acid and carbon dioxide over molybdenum carbide catalysts." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1065.
Повний текст джерелаThis work focuses on the synthesis of supported molybdenum carbides and evaluating their catalytic performance in succinic acid hydrogenation reactions in aqueous phase using batch reactor and carbon dioxide hydrogenation in gas phase using continuous flow reactor. The catalysts were prepared by the temperature programmed reduction carburization method, where the parameters were modified leading to different molybdenum to carbon ratios. The different catalysts tested were active in converting succinic acid to gamma butyrolctone and more remarkably butyric acid which is not reported in significant quantities in this reaction with precious metal based catalysts. The catalysts containing more carbon contents that were prepared by increasing the gas hourly space velocity showed higher activity in converting succinic acid and higher selectivity to butyric acid. The intermediates were then converted to tetrahydrofuran, butanol, 1,4-butanediol and butane gas. The deactivation observed while recycling the catalyst was mainly attributed to a decrease in the amounts of carbidic molybdenum and carbidic carbon, as demonstrated by XPS analysis. Preliminary tests for these catalysts in carbon dioxide hydrogenation showed that they functioned mainly as reverse water gas shift catalysts, and the excess of carbon hinders the catalytic activity in an opposite manner of the reaction in aqueous phase. The support seems playing a role in the reactivity of the catalysts, carbon dioxide conversion as well as methane and methanol selectivity increased in the order: molybdenum carbide supported on DT51 TiO2 > P25 TiO2 ˜ ZrO2
Lo, Enlin. "Sustainable Production of Bio-based Succinic Acid from Plant Biomass." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7693.
Повний текст джерелаAshley, Christopher R. "A fundamental examination of the interactions between thermo-mechanical pulp and water in the presence of alkenyl succinic anhydride /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5455.
Повний текст джерелаBlower, Patrick. "Spectroscopic and Thermodynamic Studies of the Adsorption of Atmospherically Relevant Dicarboxylic Acids at the Vapor/Water Interface." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/13225.
Повний текст джерелаLudlam-Brown, Ian Richard. "The physico-chemical and compaction properties of powders modified by alternative crystallisation conditions." Thesis, University of Bradford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390447.
Повний текст джерелаBradfield, M. F. A. (Michael Ford Alexander). "Continuous production of succinic acid by Actinobacillus succinogenes : steady state metabolic flux variation." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/40826.
Повний текст джерелаDissertation (MEng)--University of Pretoria, 2013.
gm2014
Chemical Engineering
unrestricted
Hneine, Waël. "Valorisation catalytique d’un acide carboxylique issu de l’industrie sucrière." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1080.
Повний текст джерелаThis thesis is focused on the catalytic conversion of aconitic acid (a co-product of sugarcane industry) into molecules of industrial interest, by two catalytic ways. 1) By homogeneous catalysis, the acid hydrogenation into polyols, was carried out in a batch reactor using a Ru complex [Ru(acac)3/Triphos]. The various reaction parameters was optimized in the model reaction of hydrogenation of succinic acid into 1.4-butanediol. Subsequently, these optimal reaction conditions were used for the hydrogenation of aconitic acid and resulted to a predominant formation of 2-methyl 1,4-butanediol. 2) By heterogeneous catalysis, the hydro-cyclization reaction of aconitic acid into MTHF or lactones, was performed in a continuous reactor in the presence of copper catalysts, using aconitic acid solutions in ethanol as substrate. The different conditions of the catalytic test and catalyst synthesis was optimized. Furthermore, the different catalysts tested in this thesis work was characterized using complementary techniques (BET, Elementary analysis, XRD, XPS and TEM) in order to correlate the superficial properties to the catalytic activity
Bashal, Ali Habib. "Aqueous phase hydrogenation of succinic acid using mono-and bi-metallic ruthenium-based catalysts." Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3021601/.
Повний текст джерелаMatos, Mariana Campos de. "Efficient succinic acid production from glycerol by actinobacillus succinogenes using dimethyl sulfoxid as electron acceptor." Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/7818.
Повний текст джерелаHodes, Jing [Verfasser], Reinhard H. H. [Gutachter] Neubert, Thomas [Gutachter] Gassenmeier, and Volkmar [Gutachter] Vill. "Investigation of the mode of action of succinic acid and amino acids during hair bleaching treatment / Jing Hodes ; Gutachter: Reinhard H. H. Neubert, Thomas Gassenmeier, Volkmar Vill." Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2019. http://d-nb.info/1210728885/34.
Повний текст джерелаインダ, プラティヴィ アウリア, and Aulia Indah Pratiwi. "Study on succinic acid extraction by liquid membranes and aqueous two-phase systems containing ionic liquids." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB12902967/?lang=0, 2015. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB12902967/?lang=0.
Повний текст джерелаSuccinic acid is widely used in many industrial sectors; pharmacy, textile, food, etc. The bio-production of succinic acid from renewable resource was desired because the petrochemical production of succinic acid became costly. In this study, the extraction and separation techniques of succinic acid by liquid membranes (LMs) and aqueous two-phase system (ATPS) containing ionic liquids (ILs) were exploited. The permeation mechanisms and optical conditions were elucidated.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
Qiao, Ning. "Investigation of carbamazepine-nicotinamide cocrystal solubility and dissolution by a UV imaging system." Thesis, De Montfort University, 2014. http://hdl.handle.net/2086/10201.
Повний текст джерелаTapin, Benoît. "Préparation et caractérisation de catalyseurs bimétalliques Re-Pd/TiO2 pour l'hydrogénation de l'acide succinique issu de la biomasse." Thesis, Poitiers, 2012. http://www.theses.fr/2012POIT2299/document.
Повний текст джерелаThe objective of this work is to synthesize bimetallic catalysts Re-Pd/TiO2 active and strong enough in hydrothermal environment to hydrogenate selectively the succinic acid (SUC) to 1,4-butanediol (BDO). At first, monometallic 2%Pd/TiO2 catalysts are prepared and characterized by various physico-chemical methods. The results show the importance of several parameters on the catalyst properties and catalytic performances. Palladium catalysts are very selective to γ-butyrolactone but few to BDO. Various rhenium contents are then deposited on 2%Pd/TiO2 catalysts (by successive impregnation (SI) and catalytic reduction (CR)). The existence of an interaction between both Pd-Re metals is revealed using several techniques of characterization (H2 chemisorption, model reaction of cyclohexane dehydrogenation, TPR, XPS, TEM-EDX). Adding rhenium both allows enhancing the reaction rate of SUC transformation and improving the selectivity to BDO. For catalysts prepared by SI, important quantities of rhenium (3-4%) are needed for optimal effect, while the deposit must be limited to lower contents (< 1%) when using the CR method. Nevertheless, catalysts prepared by SI lead to better activity and selectivity to BDO
Ly, Bao Khanh. "Hydrogénation de l'acide succinique en phase aqueuse pour l'obtention sélective de 1,4-butanediol." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10053.
Повний текст джерелаThe aim of our research project is the hydrogenation of the succinic acid in aqueous phase at 160°C, under 150 bar hydrogen to obtain selectively 1,4-butanediol (BDO) by using x%Re- 2%Pd/TiO2 catalyst. Palladium monometallic catalysts allow us to obtain selectively the intermediate product γ-butyrolactone and very little BDO. Their catalytic activity depends on the dispersion of the metallic phase. The reaction can be extended until obtaining BDO by adding the rhenium to palladium based monometallic catalysts. Firstly, we have tried two ex situ methods to add the rhenium: catalytic reduction (CR) and successive impregnation (SI). The best selectivity to BDO is 90% with the presence of 3,4%Re-2%Pd/TiO2 prepared by IS method. Moreover, for both deposition methods, the rhenium in the bimetallic catalysts is reoxidized with air and then leached into the aqueous phase. Despite leaching and redeposition of rhenium under hydrogen pressure, the behavior of bimetallic catalysts prepared by the two methods (CR and SI) is different. In situ deposition of the rhenium leads to promising bimetallic catalysts: SBDO = 73% with 2% of rhenium
Halder, Dibyadeep. "Toxicity of opal Australian paper weak black liquors towards actinobacillus succinogenes 130Z." Thesis, Federation University Australia, 2022. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/184110.
Повний текст джерелаMaster by Research
Halder, Dibyadeep. "Toxicity of opal Australian paper weak black liquors towards actinobacillus succinogenes 130Z." Thesis, Federation University Australia, 2022. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/183622.
Повний текст джерелаMasters by Research
Jacquel, Nicolas. "Synthesis and properties of polyesters based on poly(butylene succinate), a renewable polymer." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0127.
Повний текст джерелаPolymers issued from biomass present a growing interest, since they seem to be a suitable alternative to conventional petrochemical polymers. Among the newly developed monomers, bio-based succinic acid received a particular attention for its application in the synthesis of aliphatic polyesters such as poly(butylene succinate). The present thesis reports the synthesis of this polymer via the direct esterification of succinic acid and 1,4-butanediol in a 7.5 L pilote scale reactor. Main process parameters such as the diol exces, the trans-esterification temperature as well as the purity of succinic acid have been studied. In addition a special attention was taken to highlight the influence of the catalyst (its type, quantity ...) on the synthesis and on the stability of the resulting polymer. Then several strategies of modification of poly(butylene succinate) have been studied to improve the processability of the polymer via film extrusion blowing and to enhance the properties of polymer films. To that end the introduction of branching agents, silica nanofillers as well as rigid comonomers have been studied
LONGO, VALERIA. "A protein-based biorefinery for bulk chemicals production." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2013. http://hdl.handle.net/10281/41977.
Повний текст джерелаSacan, Lale. "Synthesis And Electrochromic Properties Of Conducting Polymers Of Succinic Acid Bis-(2-thiophen-3-yl-ethyl)ester And Their Use In Electrochromic Devices." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607292/index.pdf.
Повний текст джерелаan, Lale M.Sc., Department of Chemistry Supervisor: Prof. Dr. Levent Toppare June 2006, 59 pages A new monomer
succinic acid bis-(2-thiophen-3-yl-ethyl)ester (SATE) was synthesized through the esterification reaction of 2-thiophen-3-yl-ethanol and succinyl chloride. The chemical structure of monomer was characterized via Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Electrochemical behaviors of SATE alone and SATE in the presence of thiophene were studied by cyclic voltammetry (CV). The synthesis of homopolymer and copolymer were achieved via constant potential electrolysis. Both homopolymer (PSATE) and copolymer [P(SATE-co-Th)] were characterized by various techniques including cyclic voltammetry, FTIR, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermal Gravimetry Analysis (TGA) and UV-VIS Spectrophotometer. Conductivities of samples were measured by four probe technique. The electrochromic properties of the polymers were investigated via spectroelectrochemistry, colorimetry and switching studies. In addition, dual type electrochromic devices (ECDs) composed of PSATE, P(SATE-co-Th) and poly(3,4-ethylenedioxythiophene) (PEDOT) were constructed and evaluated. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis Spectrophotometer and Cyclic Voltammetry. They have shown to possess good switching times, reasonable contrasts, high stabilities and optical memories.
Delhomme, Clara [Verfasser], Dirk [Akademischer Betreuer] Weuster-Botz, and Fritz Elmar [Akademischer Betreuer] Kühn. "Process Integration of Fermentation and Catalysis for the Production of Succinic Acid Derivatives / Clara Delhomme. Gutachter: Fritz Elmar Kühn. Betreuer: Dirk Weuster-Botz." München : Universitätsbibliothek der TU München, 2011. http://d-nb.info/1019587431/34.
Повний текст джерелаXiberras, Joeline [Verfasser], Elke [Akademischer Betreuer] Nevoigt, Elke [Gutachter] Nevoigt, Sebastian [Gutachter] Springer, and Pau [Gutachter] Ferrer. "Engineering the central carbon metabolism of Saccharomyces cerevisiae for succinic acid production from glycerol / Joeline Xiberras ; Gutachter: Elke Nevoigt, Sebastian Springer, Pau Ferrer ; Betreuer: Elke Nevoigt." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2020. http://d-nb.info/1205545026/34.
Повний текст джерелаALMEIDA, ERIKA V. de. "Estudo da degradação de reagentes liofilizados para radiodiagnóstico por cromatografia líquida de alta eficiência (HPLC) e espectrometria de massas (MS)." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23987.
Повний текст джерелаMade available in DSpace on 2015-10-22T16:54:02Z (GMT). No. of bitstreams: 0
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Santos, JoÃo Evangelista de Ãvila dos. "Potential study of chemical and pharmacological of secundary metabolites of coast cearense fungi: Aspergillus sp." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17209.
Повний текст джерелаThis study aimed to the chemical and pharmacological research of biodiversity of marine fungi associated with sediment from the coastline of northeastern Brazil, especially the state of CearÃ. From the collection of marine sediments at the beach Pecem - SÃo GonÃalo do Amarante-CE, were cultivated various fungi, of which the strain identified as Aspergillus sp. (BRF 087), showed a preliminary cytotoxic activity. The methodology has been directed in finding secondary metabolites with cytotoxic activity using a kinetic fungus study was grown in four different media, BD (potato dextrose), BDL (potato dextrose and yeast), MPD (malt, peptone and dextrose ) and MntPL (mannitol, peptone and yeast) and in different culture periods (7, 14, 21, 28 days). This procedure resulted in the isolation of nine diketopiperazines two tetrapeptides cycle, 3 derivatives of succinic acid and p-hydroxyphenylacetic acid, characterized as cyclo (L-Pro-L-Leu) (A-1), cyclo (L-Pro-L -Phe) (A-2), cyclo (4-OH-Pro-Leu) (A-3), cyclo (4-OH-Pro-Phe) (A-4), cyclo (L-Pro-L-tyr ) (A-5), cyclo (L-Leu-L-Val) (A-6), cyclo (L-Phe-L-Val) (A-7), cyclo (L-Phe-L-Leu) (A-8), cyclo (L-Leu-L-Ile) (A-9), cyclo (L-Ile-L-Pro-L-Leu-L-Pro) (A-10), cyclo (Leu-Ile Leu-Phe) (A-11), 2-metilenosuccinic acid (A-12), 3-Methyl-2-metilenosuccinic (A-13), 4-metoxy-2-methylidene-4-oxobutanoic acid (A-14) and p-hydroxyphenylacetic acid (A-15). The isolation of secondary metabolites was conducted by using usual chromatographic techniques, including chromatography on reverse phase C18 column and high-performance liquid chromatography (HPLC). For structural characterization of the compounds were used customary spectrometric techniques like IR, mass spectrometry and nuclear magnetic resonance (NMR), one and two dimensional, and compared with literature data.
O presente trabalho teve como objetivo principal a investigaÃÃo quÃmico-farmacolÃgica da biodiversidade dos fungos marinhos associados a sedimentos da costa litorÃnea do Nordeste do Brasil, e em especial do estado do CearÃ. A partir da coleta de sedimentos marinhos na praia do PecÃm - SÃo GonÃalo do Amarante-CE, foram cultivados vÃrios fungos, dos quais a cepa identificada como Aspergillus sp. (BRF 087), mostrou uma atividade citotÃxica preliminar. A metodologia empregada foi direcionada na busca de metabÃlitos secundÃrios com atividade citotÃxica, atravÃs de um estudo cinÃtico do fungo que foi cultivado em quatro meios diferentes, BD (batata dextrose), BDL (batata dextrose e levedura), MPD (malte, peptona e dextrose) e MntPL (manitol, peptona e levedura) e em diferentes perÃodos de cultivo (7, 14, 21, 28 dias). Este procedimento resultou no isolamento de nove dicetopiperazinas, dois ciclo tetrapeptÃdeos, 3 derivados do Ãcido succinio e o Ãcido p-hidroxifenilacÃtico, caracterizados como ciclo (L-Pro-L-Leu) (A-1), ciclo (L-Pro-L-Fen) (A-2),ciclo (4-OH-Pro-Leu) (A-3), ciclo (4-OH-Pro-Fen) (A-4), ciclo (L-Pro-L-Tyr) (A-5), ciclo (L-Leu-L-Val) (A-6), ciclo (L-Fen-L-Val) (A-7), ciclo (L-Fen-L-Leu) (A-8), ciclo (L-Leu-L-Ile) (A-9), ciclo (L-Ile-L-Pro-L-Leu-L-Pro) (A-10), ciclo (Leu-Ile-Leu-Fen) (A-11), Ãcido 2-metilenosuccinio (A-12), Ãcido 3-metil-2-metilenosuccinio (A-13), Ãcido 4-metoxi-2-metileno-4-oxobutanÃico (A-14) e o Ãcido p-hidroxifenilacÃtico (A-15). O isolamento dos metabÃlitos secundÃrios foi realizado atravÃs do uso de tÃcnicas cromatogrÃficas usuais, incluindo cromatografia em coluna de fase reversa C18 e cromatografia lÃquida de alta eficiÃncia (CLAE). Para a caracterizaÃÃo estrutural dos compostos foram utilizadas tÃcnicas espectromÃtricas usuais como infravermelho, espectrometria de massa e ressonÃncia magnÃtica nuclear (RMN), uni e bidimensional, alÃm de comparaÃÃo com dados da literatura.
Sgaravatti, Angela Malysz. "Efeito do ácido gama-hidroxibutírico e da tirosina sobre parâmetros de estresse oxidativo em córtex cerebral de ratos jovens." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13873.
Повний текст джерелаSuccinic semialdehyde dehydrogenase (SSADH) deficiency and tyrosinemia type II are characterized by predominant tissue and blood accumulation of γ-hydroxybutyric acid (GHB) and tyrosine, respectively. Patients with SSADH deficiency and tyrosinemia type II present neurological signs and symptoms. Although mechanisms of brain damage remain unclear, they are probably related to the accumulation of GHB or tyrosine leading to possible noxious effects on central nervous system (CNS) development in those patients. Considering that the damaging consequences of oxidative stress have been implicated in a variety of disorders of CNS, the effect of GHB and L-tyrosine were investigated on some oxidative stress parameters in cerebral cortex homogenates of young rats. The in vitro and in vivo effects of GHB, or its precursor 1,4-butanediol (1,4-BD), were similar. It was observed that GHB or 1,4-BD impairs non-enzymatic antioxidant defenses and induces lipid peroxidation. On the other hand, the in vitro and in vivo effects of L-tyrosine were different. Oxidative damage to DNA was promoted while non-enzymatic and enzymatic antioxidant defenses, and thiol-disulfide redox state (SH/SS ratio) were markedly diminished by L-tyrosine in vitro. In contrast, the acute administration of L-tyrosine causes lipid peroxidation and protein oxidation, decreases non-enzymatic antioxidant defenses, alters SH/SS ratio and stimulates glucose-6-phosphate dehydrogenase activity. Taken together, it may be presumed that GHB and L-tyrosine elicit oxidative stress in cerebral cortex of young rats. If these effects also occur in the brain of patients affected by SSADH deficiency or tyrosinemia type II, it is possible that oxidative stress may contribute, at least in part, to the neurological dysfunction characteristic of these diseases.
Rabelo, Camila Abreu Borges da Silva. "Otimização da produção de hidrogênio e ácidos orgânicos em reator em batelada a partir de consórcio de bactérias autóctones e alóctones do bagaço de cana-de-açúcar." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-16042018-163435/.
Повний текст джерелаThis study evaluated the hydrogen and organic acids fermentative productions from sugarcane bagasse (SCB) as substrate in batch reactors. Three pre-treatment conditions (hydrothermal, autoclave and hydrothermal plus autoclave) of BCA and the in natura condition were evaluated in order to favor the hydrogen production. Hydrogen molar productions of 3.79 mmol/L, 3.47 mmol/L, 1.67 mmol/L and 1.01 mmol/L was found for SCB pretreated in autoclave, BCA in natura, SCB pretreated in hydrothermal system and SCB pretreated in hydrothermal system followed by autoclaving, respectively. From these values, it was decided to use autoclaved BCA as a substrate for optimization of hydrogen and organic acids productions from the design methodologies of the central compound and response surface. Ten batch reactors (R1 to R10) were monitored in triplicates with different substrate concentrations (0.8 to 9.2 g/L) and pH (4.6 to 7.4). The highest production of hydrogen (24.06 mmol/L) and 6.42 g/L of organic acids were obtained in R4 (8.0 g BCA/L and pH 7.0). Glucose, arabinose, xylose, mannose and galactose were produced and consumed throughout the operating time of all reactors, and arabinose was observed at higher concentration, 1,415.26 and 1,372.45 mg/L in R3 (8.0 g BCA/L and pH 5.0) and R8 (5.0 g BCA/L and pH 7.4), respectively. The production of hydrogen was concomitant to the formation of organic acids, mainly butyric (from 14.6 to 33.8% in R1 and R6, respectively) and succinic (from 19.5 to 26.4% in R3 and R9, respectively). The two factors analyzed, substrate concentration and pH, had significant effects on the production of hydrogen, butyric acid and succinic acid. From the results obtained with the factorial design, it was possible to verify that the maximum value of hydrogen production estimated by the model was 23.10 mmol/L, to 7.0 g BCA L and pH 7.2. The value obtained in the optimization experiment (Rotm) was 19.84 mmol/L, with an accuracy of 85.9% for hydrogen production from autoclaved BCA. Sequencing by the Illumina platform (Miseq) was performed for the identification of bacteria from the central point reactor (R9, 5.0 g BCA/L and pH 6.0), optimized reactor (Rotm, 7.0 g BCA/L and pH 7.2), autoclaved BCA and inoculum samples. In the inoculum were identified mainly bacteria similar to Clostridium bifermentans (62,69% of relative abundance), Bacillus coagulans (31,67%) and Enterobacter aerogenes (2,72%). Bacteria similar to C. bifermentans (31.91%), C. cellobioparum (32.29%), C. cellulolyticum (5.69%), C. sartagoforme (14.63%) and Paenibacillus spp. (11.67%). These bacteria were not favored under the conditions imposed on R9 (5.0 g BCA/L and pH 6.0) and Rotm (7.0 g BCA/L and pH 7.2), since the relative abundance of the bacteria in the reactor samples were completely different. In R9, bacteria similar to Lactobacillus paracasei and Escherichia hermannii were the main identified with 37.50 and 34.32% of relative abundance, respectively. In Rotm, the main bacteria identified were similar to Bacteroides sp. and Enterobacter aerogenes, with 37.35 and 27.72% relative abundance, respectively. Thus, bacterial populations, as well as the production of metabolites, were altered as a function of the imposed conditions; ie, BCA concentration, pH in batch reactors with autoclaved BCA as substrate.
Silva, Fabio Machado da. "Síntese de ácidos 3-alcóxi-3-cianopropanóicos, ácidos 2-ciano tetraidrofuran(2h-piran)-3-óicos e sua aplicação na obtenção dos respectivos ácidos succinâmicos e succínicos." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/10407.
Повний текст джерелаThis work presents the synthesis of a series of 3-alkoxy-3-cyanopropanoic acids and 2-cyanotetrahydrofuran(2H-pyran)-3-carboxylic acids of general formula HO2CCH(R2)CR1(OR)CN, where R/R2= Et/H, Et/Me, -(CH2)2-, -(CH2)3-, iso-Pr/H, sec- Bu/H, iso-Pr/Me, sec-Bu/Me and R1= H, obtained through the reaction of β-alkoxyvinyl trichloromethyl ketones [Cl3CCOC(R2)=CR1(OR)] with sodium cyanide. The methodology used in the synthesis provided high selectivity to the reaction, being observed only the formation of the expected products, through a conjugated addition the cyanide to the β-carbon of the enones and substitution of the CCl3 group by the hydroxyl ion originated from the basic medium used in the reaction. The β-alkoxyvinyl trichloromethyl ketones where R/R2= Et/H, R1= OEt and R/R2= Et/Br, R1=H, when submitted the same reaction conditions, furnished the succinimide 3,3-diethoxypyrrolidine-2,5-dione and the maleimide 3-ethoxy-1H-pyrrole-2,5-dione, respectively. In a second reaction, the synthesized 3-alkoxy-3-cyanopropanoic acids and 2- cyanotetrahydrofuran(2H-pyran)-3-carboxylic acids were used to obtain succinamic acids and succinic acids of general formula HO2CCH(R2)CR1(OR)CONH2 and HO2CCH(R2)CR1(OR)CO2H, respectively. The succinamic acids were formed by the spontaneous conversion of the cyano group to amide (partial hydrolysis) and the succinic acids were obtained by the total hydrolysis of the cyano group to carboxylic acid, under reflux and acid medium.
Este trabalho apresenta a síntese de uma série de ácidos 3-alcóxi-3-cianopropanóicos e 2-cianotetraidrofuran(2H-piran)-3-óicos de fórmula geral HO2CCH(R2)CR1(OR)CN, onde R/R2= Et/H, Et/Me, -(CH2)2-, -(CH2)3-, iso-Pr/H, sec-Bu/H, iso-Pr/Me, sec-Bu/Me e R1= H, obtidos através da reação de β-alcoxivinil triclorometil cetonas [Cl3CCOC(R2)=CR1(OR)] com cianeto de sódio. A metodologia empregada na síntese proporcionou alta seletividade à reação, sendo observada somente a formação do produto esperado, via adição conjugada de cianeto no carbono-β das enonas e substituição do grupo CCl3 pelo íon hidróxido proveniente do meio básico utilizado na reação. As β-alcoxivinil triclorometil cetonas, onde R/R2=Et/H, R1= OEt e R/R2= Et/Br, R1= H, quando submetidas as mesmas condições de reação, produziram a succinimida 3,3-dietoxipirrolidino-2,5-diona e a maleimida 3-etóxi-1H-pirrol-2,5-diona, respectivamente. Em um segundo momento, os ácidos 3-alcóxi-3-cianopropanóicos e 2-cianotetraidrofuran(2H-piran)-3-óicos sintetizados foram empregados na obtenção de ácidos succinâmicos e de ácidos succínicos, representados estruturalmente por HO2CCH(R2)CR1(OR)CONH2 e HO2CCH(R2)CR1(OR)CO2H, respectivamente. Os ácidos succinâmicos formaram-se pela conversão espontânea do grupo ciano para amida (hidrólise parcial) e os ácidos succínicos foram obtidos por reação de hidrólise total do grupo ciano para ácido carboxílico, sob refluxo e meio ácido.
Bevilaqua, Daiane Balconi. "Produção biotecnólogica de ácido succínico a partir de casca de arroz." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/4260.
Повний текст джерелаRice husk is a subproduct of the food industry, rich in carbohydrates, which can be partially fractionated and converted into fermentable sugars. In this work, it was investigated the best conditions for the conversion of the residual biomass, rice husks, into succinic acid, an important start molecule for the synthesis of the chemo-pharmaceutical industry. With the goal of the separation of lignin and transformation of cellulose and hemicellulose into sugars, the rice husks were submitted, initially, to acid hydrolysis, in autoclave and in pressurized polytetrafluoroethylene reactor. The hydrolysis conditions were optimized by factorial design for the pressurized acid hydrolysis; temperature, time and acid catalyst concentration (HCl or H2SO4) were evaluated. For the acid hydrolysis in autoclave, it was optimized the ratio rice husks mass: acid volume, time and concentration of HCl or H2SO4. It was observed that the sugar production by using autoclave was lower than by the pressurized hydrolysis system, needing further concentration of the hydrolysate for the subsequent fermentation step. The best results were obtained with the polytetrafluoroethylene reactor, by 59 bar, with HCl 0,26 mol L-1, at 175°C and reaction time of 46 min, yielding 19.0 g L- 1 of glucose and 3.01 g L- 1 of xylose. The efficiency of different detoxification methods of the hydrolyzed rice husk were evaluated; the combined method of pH adjustment plus adsorption on active carbon was the most effective by eliminating inhibitors, without appreciable reduction of the sugar concentration. The detoxified hydrolysate was sterilized and adjusted at pH 7 and fermented with A. succinogenes at 37 ° C, in anaerobic medium, occurring the conversion of the two main monosaccharides, glucose and xylose, into succinic acid. The nutrient concentration and the agitation rate of the medium were also optimized by factorial design. As a result, after 54 h of static fermentation, the hydrolysate was supplemented with 8.40 g L-1 yeast extract and 1.40 g L -1 of NaHCO3, to yield 59.9% succinic acid. Almost all of the sugar at this time was consumed and converted to succinic acid; at the same time, acetic and formic acid are formed, but, in low concentrations related to the production of succinic acid, not compromising the yield of the process. For the succinic acid extraction and purification, the fermentate was submitted to the solid phase extraction procedure; cartridges with different extraction phases were tested, and among them, the ion exchange one was the only effective, with recoveries up to 96%. After solid phase extraction, the eluted solution, containing 12.05 g L- 1 succcinic acid, was lyophilized, and crystals of succinic acid with 80.7% (m m- 1) were obtained. The raw material used in the bioprocess has no commercial value, representing a zero cost carbon source, which reveals itself adequate to the succinic acid production by fermentation with A. succinogenes, after hydrolysis. The use of the residual rice husk can contribute to the mitigation of the environmental impact resulting from the illegal discharge in the environment.
A casca de arroz é um subproduto da indústria de alimentos, rico em carboidratos, que pode ser fracionada e, parcialmente, convertida em açúcares fermentescíveis. Neste trabalho, investigou-se as melhores condições para a conversão da biomassa residual, casca de arroz, em ácido succínico, importante insumo para a síntese industrial farmoquímica. Com o objetivo de separação da lignina e transformação da celulose e da hemicelulose em açúcares, a casca de arroz foi submetida, inicialmente, à hidrólise ácida em autoclave e em reator de politetrafluoretileno, à pressão. As condições de hidrólise foram otimizadas através de planejamento fatorial, sendo avaliado na hidrólise ácida pressurizada, a influência da temperatura, do tempo e da concentração do catalisador ácido (HCl ou H2SO4); já, na hidrólise em autoclave, otimizou-se a relação massa de casca de arroz : volume de solução ácida, tempo e concentração de HCl ou H2SO4. Observou-se que a produção de açúcares em autoclave é inferior à do sistema de hidrólise à pressão, necessitando, inclusive, concentração do hidrolisado para utilização na etapa fermentativa. Os melhores resultados foram obtidos com o reator de politetrafluoretileno, à pressão de 59 bar, com 0,26 mol L-1 de HCl, temperatura de 175 °C e tempo de reação de 46 min, produzindo-se 19 g L-1 de glicose e 3,01 g L-1 de xilose. Avaliou-se a eficiência de diferentes métodos de destoxificação do hidrolisado de casca de arroz, sendo o método combinado, de ajuste de pH seguido de adsorção em carvão ativado, o mais eficaz na eliminação de inibidores, sem redução apreciável da concentração de açúcares. O hidrolisado destoxificado foi esterilizado, ajustado a pH 7 e fermentado com A. succinogenes, à 37 ºC, em meio anaeróbio, ocorrendo a conversão dos monossacarídeos predominantes, glicose e xilose, em ácido succínico. A concentração dos nutrientes e a velocidade de agitação do meio também foram otimizadas por meio de planejamento fatorial. Após 54 h de fermentação estática do hidrolisado, suplementado com 8,40 g L-1 de extrato de levedura e 1,40 g L-1 de NaHCO3, o rendimento em ácido succínico foi de 59,9%. Praticamente, toda a concentração de açúcar é consumida neste tempo e convertida em ácido succínico; simultaneamente, formam-se ácido acético e fórmico, porém, em baixas concentrações em relação à produção de ácido succínico, não comprometendo o rendimento do processo. Para a extração e purificação do ácido succínico, o fermentado foi submetido ao procedimento de extração em fase sólida; cartuchos com diferentes fases extratoras foram testados, e, dentre eles, somente o de troca iônica se mostrou efetivo, com recuperação de até 96,0%. Após a extração, o eluido da extração em fase sólida, contendo 12,0 g L-1 de ácido succínico foi liofilizado, obtendo-se cristais com pureza de 80,7% (m m-1). A matéria-prima utilizada no bioprocesso, casca de arroz, não tem valor comercial, representando fonte de carbono de custo zero, que se revelou adequada à produção de ácido succínico por meio de fermentação com A. succinogenes, após hidrólise. O aproveitamento da casca de arroz residual pode contribuir para a mitigação do impacto ambiental resultante da disposição ilegal no ambiente.
Berná, Galiano Antonio. "Estudio espectroelectroquímico de los equilibrios ácido-base de especies adsorbidas sobre electrodos metálicos con superficies monocristalinas bien definidas." Doctoral thesis, Universidad de Alicante, 2014. http://hdl.handle.net/10045/45809.
Повний текст джерелаMizzi, Benoît. "Méthodologie générale pour la conception d'une extraction liquide-liquide réactive : application à la séparation d'un acide carboxylique issu d'un milieu fermentaire." Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/17776/1/MIZZI_Benoit.pdf.
Повний текст джерелаKaboré, Abdoul Karim. "Étude de l’influence de l’aération sur la mise en œuvre d’un procédé de production d’acide succinique par Corynebacterium glutamicum 2262." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0026/document.
Повний текст джерелаSuccinic acid is a linear and bi-functional molecule that has several practical applications including food, chemical and pharmaceutical industries. Thanks to increased knowledge on metabolism and pathway regulation of industrially relevant organisms, to the development of performant genetic tools and process engineering, recombinants strains (Escherichia coli, Corynebacterium glutamicum etc.) have been reported to be able to produce up to 100 g.L-1 with interesting yields (> 1.5 mole per mole glucose). C. glutamicum is well known as one of the best industrial producers of numerous amino acids (glutamate, lysine etc.). However, recent studies of C. glutamicum revealed its capability to produce several organic acids (succinate, lactate, acetate, etc.). In this work, we have deleted the ldhA gene of C. glutamicum by using a plasmid vector pk19mobsacBΔldhA. We demonstrated that the mutant and the wild type presented similar growth kinetics with maximal growth rate of about 0.7 h-1. We studied also the effects of oxygenation on C. glutamicum 2262 ΔldhA through cultures at different kLa and it appeared that lower kLa (<33 h-1) favored organic acids production wile higher favored bacterial growth. Furthermore, we designed a tri-phasic process with transition phase by regulation of dissolved oxygen concentration which resulted in the production of 327 mM of succinic acid with a yield of 0.94 mole per mole glucose. The application of the designed process to C. glutamicum 2262 wild type that normally produces lactate with a lactate to succinate production ratio up to 13.3 mol.mol-1, resulted in succinate concentration up to 793 mM (94 g.L-1) and 785 mM (71 g.L-1) of lactate. The succinate production yield was 1.1 mole per mole glucose and acetate production was negligible. These results underlined the importance of aerobic to anaerobic transition in succinate production processes of facultative aerobes and the necessity to engineer not only the microorganism but also the process. Finally, scale-down study have demonstrated the robustness of C. glutamicum against the oxygen gradients in bioreactor
Mohamad, Isa Muammar Bin. "Low Noise Amplifiers using highly strained InGaAs/InAlAs/InP pHEMT for implementation in the Square Kilometre Array (SKA)." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/low-noise-amplifiers-using-highly-strained-ingaasinalasinp-phemt-for-implementation-in-the-square-kilometre-array-ska(31b6cbae-7b7e-43fe-a612-b3555dd2263d).html.
Повний текст джерелаVan, Heerden Carel Daniel. "Continuous succinic acid fermentation by Actinobacillus succinogenes." Diss., 2012. http://hdl.handle.net/2263/26922.
Повний текст джерелаLI, YUAN-SHUAN, and 李芫瑄. "The study of catalysts for succinic acid hydrogenation." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8c2gb2.
Повний текст джерела東海大學
化學工程與材料工程學系
107
1,4-butanediol(BDO), gamma-butyrolactone(GBL) and tetrahydrofuran(THF) are important chemical feedstocks. They are currently produced from fossil fuels. Considering the limitation of fossil fuels, we need to find alternative routes to produce these chemicals. The US department of energy has included succinic acid among the top 12 value added bio-based chemicals. In this study, succinic acid was used to produce BDO, THF and GBL. Core-shell catalysts of Re-Ru@SiO2, Ru@SiO2, Re-Pd@SiO2 and Pd@SiO2were prepared for catalyzing the hydrogenation of succinic acid. XRD, FE-SEM, TEM and TPR were used to characterized the catalysts. The hydrogenolysis of succinic acid was carried out under the conditions of reaction temperature in the range of 110-190 ℃, hydrogen pressure of 1100 psi, reaction time in the range of 0-36 hr and reactant concentration of 10%. The maximum 1,4-butanediol yield obtained was 42.63%. The maximum gamma-butyrolactone yield obtained was 84.66%. The maximum tetrahydrofuran yield obtained was 52.71%.
Wang, Jun-Yue, and 王俊岳. "Catalyst studies for the esterification of succinic acid and butyric acid." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/84395108937094009010.
Повний текст джерела東海大學
化學工程與材料工程學系
100
Diethyl succinate and ethyl butyrate are because of their non-toxic, good solubility, less volatile, fruit flavor, and other characteristics, are important synthetic spices and food additives.They are widely used in food,spices,pharmaceuticals,household chemicals and paint industries. This thesis studies the effects of mixed metal oxide catalysts, reaction temperature, reaction time on the esterification of succinic acid and butyric acid with ethanol to produce diethyl succinate and ethyl butyrate. For the succinic acid esterification,TiO2-SiO2 catalyst had the best catalytic perfornance with the maximum diethyl succinate yield of 98.11% at 210℃ and 6hr. For the butyric acid esterification,TiO2-SiO2 catalyst had the best catalytic performance with the maximum ethyl butyrate yield of 97.47% at 170℃ and 6hr. XRD、TFSEM、TGA、BET and EDS were used to characterize TiO2-ZrO2,TiO2-Al2O3,ZrO2-Al2O3 ,TiO2-SiO2 catalysts which were prepared by a co-precipitation method.
Kaul, Arvind. "Remediation of heavy-metal contaminated soils using succinic acid." Thesis, 1992. http://hdl.handle.net/1957/37052.
Повний текст джерелаGraduation date: 1993
Chen, Cheng-heng, and 陳政宏. "Modeling and Optimization of the Production of Succinic Acid." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/05720843693249943503.
Повний текст джерела國立臺灣科技大學
化學工程系
102
Succinic acid is the precursor of petroleum products.Therefore,utilize biotechnological methods of production, to replace traditional reactions of petroleum,In the present study we conducted a set of Actinobacillus succinogensproduction process can be described by a mathematical model,parameter of model were obtained using Genetic Algorithms.Next, the best application of optimized mathematical models by Genetic Algorithms to find optimal operating conditions.According to different objective function to find the best feed flow rate, outflow rate, feed concentration, switching times for feed flow and switching times for outflow.
Macedo, Alfredo Pina de. "Production of succinic acid from eucalyptus kraft pulp hydrolysates." Master's thesis, 2019. http://hdl.handle.net/10773/30291.
Повний текст джерелаO ácido succínico é um importante “building block” interveniente na indústria química, sendo uma molécula base na síntese de uma vasta gama de produtos. Apesar das suas origens biológicas, o ácido succínico era produzido exclusivamente pela indústria petroquímica, acarretando grandes desvantagens ambientais tais como a libertação de CO2. Presentemente, com o desenvolvimento da biotecnologia e devido a um aumento de pressões ambientais e económicas, uma parte consideravel da produção de ácido succínico passou a ser feita através de bioprocessos. A produção biológica de ácido succínico contrasta com a petroquímica ao consumir CO2, permitindo assim contribuir para uma redução das emissões. Adicionalmente, já se encontra documentada a possibilidade de utilizar resíduos agroindustriais, nomeadamente lenhocelulósicos, como fonte de substrato para a produção de ácido succínico. Destes, é possível destacar os resíduos produzidos pelas indústrias papeleiras, nomeadamente resíduos da madeira onde o processo kraft se poderá revelar um forte candidato como pré-tratamento para bioprocessos. O objetivo deste trabalho centrou-se na produção de ácido succínico a partir de pasta celulósica obtida pela deslenhificação de madeira de Eucalyptus globulus através do cozimento kraft. Para isso, fez-se a hidrólise enzimática das celulose e hemiceluloses presentes nas pastas kraft, para produção de um hidrolisado formado pelos respetivos monossacáridos. Este foi fermentado pela bactéria Actinobacillus succinogenes, biocatalisador deste processo, em operação batch e fed-batch. Através da fermentação do hidrolisado de pasta de madeira obteve-se uma concentração de ácido succínico de 19.93 g/L, com produtividade e rendimento de 0.399 g/L.h e 0.331 gacido succínico/gaçucares respetivamente. Estes valores foram melhorados após a adição de carbonato de magnésio, apesar de se ter verificado um aumento na produção de subprodutos. No caso do fed-batch, verificou-se uma elevada produção de ácido láctico que a certa altura, superou a produção de ácido succínico. Não obstante, estes resultados podem ser utilizados a nível industrial, com o objetivo de produzir ambos os ácidos orgânicos, uma vez que estes poderão ser separados. Este trabalho serviu de referência para estudos futuros utilizando resíduos de madeira como substrato, de forma a proceder à sua integração numa biorrefinaria de pasta de papel que se enquadre num modelo de Economia Circular.
Este trabalho foi realizado no âmbito do Projeto inpactus – Produtos e Tecnologia inovadores a partir do Eucalipto, Projeto N.º 21874 financiado no Portugal 2020 através do Fundo de Desenvolvimento Regional (FEDER), Compete 2020, nº246/eixo II/2017.
Mestrado em Biotecnologia
Tzu-YuLi and 李姿諭. "Strategies for Effective Recovery of Succinic Acid from Fermentation Broth." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/28jag3.
Повний текст джерелаHsu, Hua-Ju, and 徐華嬬. "Isolation and identification of a lactic acid, succinic acid and acetic acid producing strain from bovine rumen." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/46055724944373417338.
Повний текст джерела國立中正大學
化學工程研究所
102
Succinic acid and lactic acid are two important organic acids in the chemical industry. They can be used as the main ingredient or intermediate products, such as drugs, food additives, cleaners. In this study, we focused on the selection of microorganisms, optimization of media conditions, and recombination of microorganism metabolic pathways to improve concen- tration of succinic acid or lactic acid. Rumen contains a variety of microorganism, so this study used the rumen contents from the cattle as a source. The enrichment culture medium contains the monensin, which can inhibit a part of rumen microorganisms, like protozoan and methanogenus. Under anaerobic conditions, 118 strains producing organic acid were isolated with yellow loop as selective marker presented in the bromocresol green medium. Finally, a strain No. 8 that can produce succinic acid, lactic acid, and other acids was named as the strain No. 8. The 16s rRNA sequence analysis placed strain No. 8 within the family of E. coli. The most closely related members of the family E. coli have a 16s rRNA similarities of 99 % to strain No. 8. In addition, we had also amplified the genes for the metabolic pathways of lactate and acetate, included L-ldhA, D-ldhA, mgsA and pta genes, to check whether here are mutations in these genes causing, a strain No. 8 with a higher yield of lactic acid and succinic acid. Results of the batch culture in 5L fermentor showed that strain No. 8 could produce 56.58 g/L succinate from 50 g/L glucose, with final average yield of 18.2 % (w/w). Simultaneously, this strain could also produce lactate at 23.69 g/L, with final average yield of 65 % (w/w). We attempted to change carbon source in the culture medium by replacing glucose with inexpensive glycerol. Results showed that strain No. 8 could not metabolize glycerol. Furthermore, this study works on the recombinant DNA of No. 8. We tried to remove target genes by the method of gene knock-out.
Yang, Yu-Jui, and 楊育睿. "Catalytic Benzylation of Succinic Acid Disodium Salt by Phase-transfer catalysis." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/94846048486663193635.
Повний текст джерела國立中興大學
化學工程學系所
94
The present syudy is to investigate the catalytic benzylation of succinic acid disodium salt by phase-transfer catalysis in liquid-liquid and solid-liquid system. In liquid-liquid system, we chose benzyltributylammonium bromide (BTBAB) to be the major catalyst. The experimental results show that the more the amounts of catalyst or aqueous reactant, the faster the reaction rate will be. When the agitation speed exceeds 300 rpm, the mass transfer resistance at the liquid-liquid interface can be neglected and the yield of product can reach to 80%. But without any agitation, the yield of product only can reach to 8.6%.Using MIBK as the solvent is better than using Heptane. Different phase-transfer catalysts were employed to compare their catalytic efficiency, and the reactivity order was found: tetrabutylphosphonium bromide ≈ benzyltributylammonium bromide > tetrabutylammonium bromide >Aliquat 336. The kinetics of second-order reaction can be applied to describe the overall reaction rate successfully. In comparing phase-transfer catalysis in solid-liquid and liquid-liquid systems, we chose Aliquat 336 to be the major catalyst. The experimental results show that both in solid-liquid system and liquid-liquid system, the more the amounts of catalyst or aqueous reactant, the faster the reaction rate will be. When the agitation speed exceeds 200 rpm, the mass transfer resistance at the interface can be neglected. Using MIBK as the solvent is better than using Heptane in solid-liquid system, but worse in liquid-liquid system. In solid-liquid system, adding some water can not produce the omega-phase to improve the reaction. In liquid-liquid system, adding more water makes more interfacial area than to have better reaction. Different phase-transfer catalysts in solid-liquid system were employed to compare their catalytic efficiency, and the reactiveity order was found: Aliquat 336> tetrabutylammonium bromide > tetrabutylphosphonium bromide > benzyltributylammonium bromide. The kinetics of pseudo-first-order reaction can be applied to describe the overall reaction rate successfully.
YU, CHENG-HONG, and 洪淯誠. "Spearation of succinic acid through liquid membrane supported by PVA film." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/18315201929623507769.
Повний текст джерела東海大學
化學工程與材料工程學系
104
The main purpose of this research is to extract the succinic acid by a liquid membrane from the aqueous solution. To strengthen the stability of the liquid membrane in operation, the system of supported liquid membrane is adpoted. And crosslinked polyvinyl alcohol film is used as a separator plate to ensure that the liquid membrane is isolated from the aqueous solution. This study is divided into three parts. The first part is focused on crosslinking of the PVA film by acid catalyzed formaldehyde to enhance the durability of the film. Different concentrations of formaldehyde solution were added to control the degree of crosslinking. Thickness, degree of swelling,the amount of catalyst addition and pore formation in the film forming process were discussed. The second part is about the study of phase equilibrium of the extractant phase and water phase. Different concentrations of TOA in the octanol were used to extraction succinic acid from its aquous solution of different concentrations to explore that the distribution of the acid in the two PVA films of different degree of crosslinking were coupled with liquid membranes of different contents of the carrier to perform the extraction experiments. The effects of the concentration of feed phase and the thickness of liquid membrane on the succinic acid flux were explored. The analysis of average total flux analysis leading to the extraction resistance was discussed. Finally measurements of contact angle for the drop of liquid membrane on PVA films were presented to elaborate the effect of the affinity between film and liquid membrane on the succinic flux.
Lee, Lin-En, and 李臨恩. "Study of the process for recovering Succinic-acid from fermentation broths." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/92410596762864529078.
Повний текст джерела國立臺灣科技大學
化學工程系
103
In this research, we are probe about recovery of succinic acid from fermentation broths with process design and control. Succinic acid is extensively applies in industry and our daily lives, which is one of the most promising commodities in the chemical industry. However, the problem of manufacturing succinic acid does always exist. The recovery of succinic acid process takes up about 50% to 80% of processing cost. Many have attempted to improve and reduce separation steps, but up to now there is not a successful technology scaled up to industrial production. Despite the fact that several separation processes have been proposed to overcome this problem (precipitation, ion exchange resins, membranes, reactive extraction, and liquid-liquid extraction), none addresses the major limit of large energy and material requirements as well as waste generation. First of all, suitable thermodynamic and kinetic model are chosen to describe this process and perform the steady-state simulation by Aspen Plus. The system in this process is a reversible reaction and seeking out the optimum goal is obtained by minimizing the Total Annual Cost (TAC). After two optimum designs which are about reactive distillation column and separate distillation column are obtained, we connect each unit into a plant-wide process and recycle the un-reacted reactants. Then, we change the feed location to look for the optimum process. After that, we will discuss the dynamic simulation and control of the plant-wide process by Aspen Dynamic. A simple control strategy including level, temperature, pressure and flow control has been brought forward, and the sensitivity analysis is performed to find the suitable control of each unit. With the interference by adjusting the feed flow rate and feed composition, the proposed control strategy works effectively and holds the purity of the product.