Thèses : « Acidi succinici »

1

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.

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2008/2009
E’ 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

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2

De, Klerk Jean-Louis. « Succinic acid production by wine yeasts ». Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4228.

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Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010.
ENGLISH 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.
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3

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/.

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4

Brown, 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.

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5

Maharaj, Karishma. « Continuous succinic acid fermentation using immobilised Actinobacillus succinogenes ». Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/40818.

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Actinobacillus succinogenes cells were grown on Poraver® support particles in a packed-bed reactor. Dilution rates (D) of 0.054–0.72 h-1 were investigated. Glucose was used as substrate. CO2 (g) was bubbled into a complex medium to satisfy the fixation requirements and maintain anaerobic conditions. At D ≥ 0.31 h-1, an initial glucose concentration of 35 g.L-1 was used; at lower dilution rates, this was increased to 60 g.L-1 in order to avoid substrate limitations. By-product formation included acetic and formic acids. A maximum productivity of 10.7 g.L-1 was obtained at D = 0.7 h-1. It was found that the system provided repeatable results at a given D. The longest steady state period was maintained for about 97 h at D = 0.31 h-1. Steady state stability was maintained for > 72 h at D < 0.31 h-1. For periods longer than 75 h, however, inhibitory acid titres resulted in a gradual decline in productivity. At higher dilution rates, long-term stability could not be maintained. The low acid titres produced significant biofilm sloughing following aggressive biofilm growth, resulting in oscillatory system behaviour. For fermentation times < 115 h, the dilution rate was secondary to the attachment area in determining the total biomass at steady state. Total biomass values were then used to determine specific rates. A clear trend was observed, with the specific glucose consumption rate, and specific acid production rates, increasing with increasing D. This was explained by assuming a maintenance-driven system at all Ds studied. A product analysis indicated that at ΔS < 15 g.L-1, pyruvate formate lyase was the preferred oxidative route. A shift to the pyruvate dehydrogenase pathway occurred at higher ΔS values, so that the highest YSS values obtained exceeded 0.85 g.g-1. A decrease in C3 by-product formation resulted in high YSS values being maintained, indicating an additional, unknown source of nicotinamide adenine dinucleotide (NADH). It is recommended that any process utilising immobilised A. succinogenes cells should operate at an intermediate D, in order to maintain long-term reactor stability, high productivities and good yields.
Dissertation (MEng)--University of Pretoria, 2013.
gm2014
Chemical Engineering
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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.

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There is a huge global challenge to establish alternative forms of energy in order to cope with the increasing worldwide energy demand, currently based on finite fossil fuel reserves. In the transportation sector, renewable liquid fuels, such as bio-ethanol and biodiesel which are made from biomass and are substitutes for the petroleum-derived gasoline and diesel, have received increasing interest. In spite of their recent development, the biofuel industries cannot compete with conventional liquid fuels because of their higher costs. Decisive changes are required to improve their economic sustainability, such as the establishment of novel processes that utilize their by-products for the production of value-added chemicals. In this study, the bioconversion of glycerol, which is the main by-product of the biodiesel industry, to succinic acid by using the bacterium Actinobacillus succinogenes has been investigated both experimentally and computationally. Initially, the cells were adapted to accept a glycerol rich environment by performing a series of experiments. Cells from the best experiment from each run were used as inocula for the next experiment. Batch fermentations were then performed in small scale anaerobic reactors (SARs) and in lab-scale bench top reactors (B-TRs) by using the new ‘adapted’ strain. The maximum succinic acid yield, productivity and final concentration obtained from this bioprocess were found to be 1.29 g/g, 0.27 g/L/h and 29.3 g/L, respectively. Moreover, cells have also grown successfully in both synthetic and biodiesel-derived crude glycerol, indicating that it is not necessary to remove the impurities that biodiesel-derived glycerol contains. Subsequently, an unstructured model that accounts for substrate and product inhibition was developed in order to predict the behaviour of experiments starting from different initial conditions. Model predictions were found to be in good agreement with experimental data obtained for both systems (SARs and B-TRs). Batch and fed-batch systems were optimized using the developed model to obtain high succinic acid productivity. Optimization results showed that productivity increased by 31% for batch and 79% for fed-batch systems. The corresponding optimal values were computed to be equal to 0.356 g/L/h for batch and 0.488 g/L/h for fed-batch systems. A semi-mechanistic model for the fungal fermentation on solid state rapeseed meal (i.e. the other main by-product of the biodiesel industry) was also constructed for small scale tray bioreactors. This fermentation targets to increase the nutrient factor of the rapeseed meal by decomposing its macromolecules to simple compounds which can then be used as a generic medium. The developed model effectively predicts the fungal growth, the temperature fluctuations and the moisture content inside the bed and the produced extracellular enzymes that break the complex compounds of rapeseed meal (i.e. proteins) to free amino acids. The economic sustainability of biodiesel production was investigated by the construction of a plant model of an integrated biodiesel biorefinery for the production of fuels (biodiesel) and chemicals (succinic acid) in Aspen Plus®. For a biodiesel plant with capacity of 7.8 ktons per year, it was found that the plant’s profitability can be increased by 60% (considering a 20 years plant life and an interest rate of 7%) if a fermentation and recovery process for producing succinic acid is added. The integrated biorefinery scheme demonstrated the highest profits (€ 9.95 M.) when compared with other scenarios which either purified or disposed of the glycerol. These results illustrate the critical role of glycerol when it is utilized as a key renewable building block for the production of commodity chemicals. It is clear, based on this work, that future studies targeting the sustainable development of biodiesel biorefineries should focus their investigation on novel bio-processes, like the succinic acid fermentation, supplementing the production of fuels with the co-production of platform chemicals.

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Mokwatlo, Sekgetho Charles. « Analysis of succinic acid-producing biofilms of Actinobacillus succinogenes ». Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/76114.

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Biofilms of the bovine rumen bacterium Actinobacillus succinogenes have demonstrated their exceptional capabilities as biocatalysts for high productivity, titre and yield production of succinic acid (SA). Succinic acid is set to become a significant building block chemical in the biobased economy. Although substantial progress has been made towards understanding the productive aspect of this microorganism with regard to its metabolic limits and performance on unrefined biorefinery stream substrates, more research is still required to address other challenges. One aspect is to understand how the biofilm biocatalyst is affected by bioreactor conditions, which would help in developing stable and highly active biofilms. For this reason the aim of this thesis was (i) to characterise how the accumulation of acid metabolites in continuous operation impacts A. succinogenes biofilms with respect to biofilm development, biofilm structure and cell activity within the biofilm, (ii) to show how shear conditions in the fermenter can be used to manipulate the biofilm structure and viable cell content of biofilms, leading to improved cell-based succinic acid productivities, and lastly (iii) to investigate the internal mass transfer effects on biofilm performance, further showing the role played by differences in shear and acid accumulation conditions in this respect. The first part of the study addressed the interaction between the biofilm and the accumulation of metabolites produced. The results showed that biofilms of A. succinogenes develop rapidly and with high activity when cultivated under low product accumulation (LPA) conditions (< 10 g L-1 SA). High product accumulation (HPA) conditions considerably slowed down biofilm development, and increased cell mortality. Under HPA conditions some cells exhibited severe elongation while maintaining a cross-sectional diameter like the rod/cocci-shaped cells predominantly found in LPA conditions. The elongated cells formed in HPA conditions were found to be more viable and thus more resistant than the clusters of rod-shaped or cocci-shaped cells. The global microscopic structure of the HPA biofilms also differed significantly from that of the LPA biofilms. Although both exhibited shedding after 4 days of growth, the LPA biofilms were more homogenous (less patchy), thicker and had high viability throughout the biofilm depth. In the second part of the study, two custom-designed bioreactors were used to evaluate the effect of shear on the biofilms. The first bioreactor allowed for in situ removal of small biofilm samples used for microscopic imaging. The second bioreactor allowed for complete removal of all biofilm and was used to analyse biofilm composition and productivity. Results clearly indicated that high shear biofilm cultivation in LPA conditions has beneficial morphological, viability and cell-based productivity characteristics. The smooth, low-porosity biofilms obtained under high shear and LPA conditions had an average cell viability of 79% (over a 3-day cultivation period) compared with the low shear value of 57%, also developed under LPA conditions. The EPS content of the high shear biofilm was 58% compared with 7% of the low shear equivalent. The cell-based (EPS excluded) succinic acid productivity for the high shear biofilm was 2.4 g g-1DCW h-1 compared with the 0.8 g g-1DCW h-1 for the low shear biofilm. This threefold increase in productivity obtained from the second bioreactor corresponded to the cell viability differences obtained from the first bioreactor. Clear evidence was provided for shear-induced shaping of the biofilm which resulted in improved volumetric glucose turnover attributes within the biofilm matrix. The last section of the study investigated internal mass transfer effects in biofilm fermentations of Actinobacillus succinogenes by performing batch fermentations using attached and resuspended biofilms as biocatalysts. In the latter, the biofilms were resuspended after initial development to simulate mass transfer-free fermentations. Intrinsic kinetics for succinic acid production obtained from resuspended fermentations predicted faster production rates than for the attached biofilm runs (biofilm thicknesses in the range of 120–200 µm), indicating internal mass transfer limitations. A developed biofilm reaction diffusion model gave good prediction of attached biofilm batch operation results by accounting for internal mass transfer in the biofilm. Biofilm effectiveness factors ranged from 75% to 97% for all batches at the inception of batch conditions, but increased with the progression of batch operation due to the increased succinic acid titres which inhibited the production rates. Analysis of pseudo-steady-state continuous fermentation data from the literature, as well as from the second part of the study, using the model developed, showed that active biofilm thickness and effectiveness factors were dependent on the shear conditions and succinic acid titres in the biofilm reactors. A simplified algorithm was developed to estimate the pseudo-steady-state glucose penetration and biofilm effectiveness of A. succinogenes biofilms without the requirement to solve the overall mass transfer model. The results clearly showed that internal mass transfer needs to be considered in biofilm fermentations involving A. succinogenes as high biomass concentrations may not always equate to increased productivities if mass transfer effects dominate.
Thesis (PhD)--University of Pretoria, 2020.
NRF
Chemical Engineering
PhD
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Andersson, Christian. « Biobased production of succinic acid by Escherichia coli fermentation / ». Luleå : Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/2578562.

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Abou, Hamdan Marwa. « Hydrogenation of succinic acid and carbon dioxide over molybdenum carbide catalysts ». Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1065.

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Ce travail de thèse porte sur la synthèse de carbures de molybdène sur support afin de tester leurs performances catalytiques dans des réactions d’hydrogénation. Dans ce but, la conversion d'acide succinique en phase aqueuse dans un réacteur discontinu et du dioxyde de carbone en phase gazeuse dans un réacteur à flux continu, ont été effectuées. Les catalyseurs ont été préparés par la méthode de carburation par réduction en température programmée, pendant laquelle des paramètres ont été modifiés conduisant à différents rapports molybdène/carbone. Les différents catalyseurs testés dans cette réaction étaient actifs pour la conversion de l'acide succinique en gamma-butyrolctone et, plus remarquablement, en acide butyrique, ce dernier n'était pas obtenu en quantités significatives avec des catalyseurs à base de métaux précieux. L’augmentation de la conversion d’acide succinique avec une sélectivité plus élevée en acide butyrique a été faite avec les catalyseurs contenant plus de carbone, préparés en augmentant la vitesse spatiale horaire gazeuse. Les intermédiaires ont été ensuite convertis en tétrahydrofurane, butanol, 1,4-butanediol et butane. La désactivation observée lors de recyclage du catalyseur a été principalement attribuée à une diminution de la quantité de molybdène et de carbone carbidique, démontrée par l'analyse XPS. Des essais préliminaires de ces catalyseurs dans l'hydrogénation du dioxyde de carbone ont montré qu'ils fonctionnaient principalement en tant que catalyseurs pour la réaction du gaz à l’eau inverse, et l'excès de carbone entrave l'activité catalytique d'une manière opposée à la réaction en phase aqueuse. Le support semble jouer un rôle dans la réactivité des catalyseurs, la conversion du dioxyde de carbone ainsi que la sélectivité en méthane et méthanol, qui ont augmenté dans l'ordre suivant: carbure de molybdène sur support DT51 TiO2> P25 TiO2 ˜ ZrO2
This 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

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Lo, Enlin. « Sustainable Production of Bio-based Succinic Acid from Plant Biomass ». Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7693.

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Succinic acid is a compound used for manufacturing lacquers, resins, and other coating chemicals. It is also used in the food and beverage industry as a flavor additive. It is predominantly manufactured from petrochemicals, but it can also be produced more sustainably by fermentation of sugars from renewable feedstocks (biomass). Bio-based succinic acid has excellent potential for becoming a platform chemical (building block) for commodity and high-value chemicals. In this study, we focused on the production of bio-based succinic acid from the fiber of sweet sorghum (SS), which has a high fermentable sugar content and can be cultivated in a variety of climates and locations around the world. To avoid competition with food feedstocks, we targeted the non-edible ‘bagasse’, which is the fiber part after extracting the juice. Initially, we studied various conditions of pretreating SS bagasse to remove most of the non-fermentable portions and expose the cellulose fibers containing the fermentable sugars (glucose). Concentrated (83%) phosphoric acid was utilized at mild temperatures of 50-80 °C for 30-60 minutes at various bagasse loadings (10-15%) using a partial factorial experimental design. After pretreatment, the biomass was subjected to enzymatic hydrolysis with commercial cellulase enzyme (Cellic® Ctec2) to identify the pretreatment conditions that lead to the highest glucose yield that is critical for the production of succinic acid via fermentation with the bacterium Actinobacillus succinogenes. As the pretreatment temperature and duration increased, the bagasse color changed from light brown to dark brown-black, indicating decomposition, which ranged from 15% to 72%. The pretreatment results were fitted with an empirical model that identified 50 °C for 43 min at 13% solids loading as optimal pretreatment conditions that lead to the highest glucose release from sweet sorghum bagasse. Biomass pretreated at those conditions and subjected to separate enzymatic hydrolysis and fermentation with A. succinogenes yielded almost 18 g/L succinic acid, which represented 90% of the theoretical yield, a very promising performance that warranties further investigation of bio-based succinic acid production from sweet sorghum bagasse, as a more sustainable alternative to succinic acid produced from fossil sources, such as oil.

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Ashley, 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.

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Blower, 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.

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Many important atmospheric processes are determined by the chemical composition of aerosols, including organic material. Dicarboxylic acids are a commonly detected class of organic material in urban, rural, and remote sites across the globe. Understanding the surface behavior of these molecules is imperative in characterizing the atmospheric fate of these molecules in aerosols, especially at an aerosol surface. In fact, little is known about their orientation, solvation, or pH dependence. This dissertation explores in molecular level detail the concentration and pH behavior of low molecular weight dicarboxylic acids at the air/water interface, which is used as a model for an aerosol surface. The solvation of the carboxylic head groups is shown to be dependent upon the length of the alkyl backbone. Indeed, the solvation of the head groups changes dramatically from very weakly solvated to typical surface solvation to near bulk solvation as the backbone increases. The orientation and conformation at the surface is fully explored to explain these differences in solvation. The pH dependence of surface adsorption is characterized, and it is shown that some acids are only surface active if they are fully protonated while others may still be surface active in singly or fully deprotonated forms. Using a combination of vibrational sum frequency spectroscopy (VSFS), surface tension, and computational modeling, the behavior at the air/water interface of four of the most relevant surface-active dicarboxylic acids (malonic, succinic, glutaric, and adipic acid) is completely described. VSFS, a surface specific optical technique, provides details about the solvation, orientation, and number density at the surface while surface tension measurements provide corollary information about the surface density. The use of computational modeling aids and confirms the spectral analysis while also providing molecular level details about the surface adsorption of the acids studied. By investigating the concentration and pH dependence of these molecules, molecular level detail is obtained which enables a complete description of these acids at an air/water interface and provides pertinent surface information on these atmospherically important organic molecules. This dissertation includes both previously published and unpublished co-authored material.

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Ludlam-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.

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Bradfield, 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.

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Continuous fermentations were performed in a novel external-recycle, biofilm reactor using D-glucose and CO2 as carbon substrates. Corn steep liquor (CSL) and yeast extract (YE) served as nitrogen sources. In anaerobic fermentations using medium containing CSL and YE, succinic acid (SA) yields were found to be an increasing function of glucose consumption. The ratio of SA to the major by-product, acetic acid (YAASA), increased from 2.4 g g-1 at a glucose consumption of 15 g L-1, to 5.7 g g-1 at a glucose consumption of 46 g L-1. For medium containing no CSL, YAASA remained near 1.97 g g-1, exceeding this for cases where biofilm grown on CSL-containing medium was present. The ratio of formic acid to acetic acid (YAAFA), for CSL-containing medium, decreased from an equimolar value (0.77 g g-1) at a glucose consumption of 10 g L-1 to zero at 46 g L-1 glucose consumed. In contrast, YAAFA for YE-only medium remained at 0.77 g g-1. Therefore, pyruvate was metabolised solely by pyruvate-formate lyase when no CSL was present. The highest SA yield obtained on glucose, SA titre and SA productivity were 0.91 g g-1, 48.5 g L-1 and 9.4 g L-1 h-1, respectively, all for medium containing CSL. Medium that included CSL significantly outperformed medium that excluded CSL, achieving 64%, 21% and 203% greater SA titres, yields on glucose and productivities respectively. Metabolic flux analyses based on the established C3 and C4 metabolic pathways of Actinobacillus succinogenes revealed that the increase in YAASA, for CSL-containing fermentations, could not be attributed to the decrease in formate and biomass formation, and that an additional source of reducing power was present. The fraction of reducing power (NADH) unaccounted for increased with glucose consumption, suggesting that the maintenance or non-growth metabolism encountered at higher SA titres differs from the growth metabolism. It is postulated that the additional reducing power originates from an active pentose phosphate pathway in non-growing cells or from an undetected component(s) in the fermentation medium. No major metabolic flux variations were found in fermentations that excluded CSL.
Dissertation (MEng)--University of Pretoria, 2013.
gm2014
Chemical Engineering
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Hneine, Waël. « Valorisation catalytique d’un acide carboxylique issu de l’industrie sucrière ». Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1080.

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Ces travaux de thèse ont porté sur la conversion catalytique de l'acide aconitique (un co-produit de la filière canne à sucre) en molécules d'intérêt industriel. Par deux voies catalytiques. 1) Par catalyse homogène, hydrogénation de l'acide en polyols, a été étudiée dans un réacteur Batch à l'aide d'un complexe catalytique actif à base de Ru [Ru(acac)3/Triphos]. L'optimisation des différents paramètres réactionnels a été effectuée sur une réaction modèle, l'hydrogénation de l'acide succinique en 1,4-butanediol. Ultérieurement, ces conditions réactionnelles optimales ont été utilisées pour l'hydrogénation de l'acide aconitique et ont permis l'obtention d'un produit majoritaire, le 2-méthyl 1,4-butanediol. 2) Par catalyse hétérogène, la réaction d'hydro-cyclisation de l'acide aconitique en MTHF ou en lactones, a été réalisée en réacteur continue en présence de catalyseurs à base de cuivre en partant de solutions d'acide aconitique dans l'éthanol. Les conditions de test catalytiques et la synthèse du catalyseur ont été optimisées. Les caractéristiques des différents catalyseurs testés ont été réalisées en faisant recours à des techniques analytiques complémentaires (SBET, Analyse chimique, DRX, XPS et MET) afin de corréler les propriétés de surface à l'activité catalytique
This 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

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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/.

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Matos, 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.

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Hodes, Jing [Verfasser], Reinhard H. H. [Gutachter] Neubert, Thomas [Gutachter] Gassenmeier et 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.

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インダ, プラティヴィアウリア, et 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.

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近年発酵生産が注目されているコハク酸の抽出分離法についてイオン液体を含む液膜法及び水性２相抽出法を用いて研究した．イオン液体を含む含浸型液膜により，受容相に塩酸水溶液を用いることでコハク酸の上り坂輸送を達成できた．次にイオン液体を含む高分子溶媒膜によるコハク酸の透過を検討した．最適な条件は含浸液膜と異なり，透過にはコハク酸の各化学種が関与していた．最後に水溶性有機溶媒やイオン液体を用いた水性２相抽出法によるコハク酸の抽出を行った．塩および糖を相分離剤とすることで，発酵液で想定されるコハク酸の80％以上の抽出が達成できた．
Succinic 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

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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.

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In this study, the ability of pharmaceutical cocrystals on improving solubility and dissolution behaviour of poorly water soluble drug has been studied by a novel technique SDI300 UV imaging surface dissolution system. Pharmaceutical cocrystals of poorly water soluble drug carbamazepine (CBZ) were synthesized, which are 1: 1 carbamazepine - nicotinamide (CBZ-NIC) cocrystal, and 2:1 carbamazepine - succinic acid (CBZ-SUC) cocrystal. Firstly, dissolution and solution mediated phase transformation behaviour (SMPT) of CBZ-NIC cocrystal was studied by in situ techniques of UV imaging and Raman spectroscopy. This study has shown that in situ UV imaging and Raman spectroscopy with a complementary technique of SEM can provide an in depth understanding of cocrystal dissolution processes. It has been found that CBZ-NIC cocrystal including other polymorphs of CBZ III and I and mixture are converting to CBZ DH during dissolution. The influence of surfactants, SLS and Tween 80, on the solubility and dissolution behavior of the CBZ-NIC cocrystal has been studied. Results show that the SMPT of CBZ III and CBZ-NIC cocrystal can be altered by inclusion of a surfactant in dissolution medium. However, CBZ III and CBZ-NIC cocrystal have shown different transformation behavior with different surfactants. The solubility and dissolution behaviour of CBZ-NIC cocrystal, CBZ-SUC cocrystal in four biomedia (simulated gastric fluid, pH1.2 HCl buffer, simulated intestinal fluid, and pH 6.8 PBS buffer) were studied. Results have shown that equilibrium solubility of CBZ samples varied in different media. The two cocrystals dissolution rates show different trends as that of parent drug CBZ III. This can be explained by that the formation of cocrystal change the dissolution ability of CBZ III.

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Tapin, 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.

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L'objectif de ce travail est de mettre au point des catalyseurs bimétalliques Re-Pd/TiO2 actifs et suffisamment robustes en milieu hydrothermal pour hydrogéner sélectivement l'acide succinique (SUC) en 1,4-butanediol (BDO). Dans un premier temps, des catalyseurs monométalliques 2%Pd/TiO2 sont préparés et caractérisés par diverses techniques physico-chimiques. Les résultats montrent l'importance d'un certain nombre de paramètres sur les propriétés des catalyseurs et leurs performances catalytiques. Les catalyseurs à base de palladium sont très sélectifs en γ-butyrolactone mais très peu en BDO. Différentes teneurs en rhénium sont ensuite déposées sur les catalyseurs 2%Pd/TiO2 (par imprégnation successive (IS) et par réduction catalytique (RC)). L'existence d'une interaction entre les deux métaux Pd-Re est mise en évidence par plusieurs techniques de caractérisation (chimisorption H2, réaction modèle de déshydrogénation du cyclohexane, RTP, XPS, MET-EDX). L'ajout de rhénium permet d'augmenter la vitesse de la réaction de transformation du SUC et améliore la sélectivité en BDO. Pour les catalyseurs préparés par IS, des quantités importantes de rhénium (3-4%) sont nécessaires pour avoir un effet optimum, alors que le dépôt par la méthode RC doit être limité à des teneurs plus faibles (< 1%). Néanmoins, les catalyseurs préparés par IS conduisent à une meilleure activité et sélectivité en BDO
The 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

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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.

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Le but du projet est d’hydrogéner l’acide succinique en phase aqueuse à 160°C, sous 150 bar d’hydrogène pour obtenir sélectivement le 1,4-butanediol (BDO) en utilisant des catalyseurs x%Re-2%Pd/TiO2. Les catalyseurs monométalliques au palladium permettent d’obtenir sélectivement le produit intermédiaire : la γ-butyrolactone et très peu de BDO est obtenu. Leur activité catalytique est fonction de la dispersion de la phase métallique. L’addition de rhénium aux catalyseurs monométalliques au palladium permet de poursuivre la réaction jusqu’à l’obtention du BDO. Nous avons d’abord essayé deux méthodes d’addition ex situ de rhénium : réduction catalytique (RC) et imprégnation successive (IS). La meilleure sélectivité en BDO obtenue jusqu’à maintenant est de 90% en présence du solide 3,4%Re-2%Pd/TiO2 préparé par IS. Quelle que soit la méthode de dépôt (RC ou IS), le rhénium dans ces solides bimétalliques est réoxydé et lixivié dans la phase aqueuse sous l’atmosphère non réductrice. Malgré la lixiviation et le redépôt du rhénium sous hydrogène, le comportement des catalyseurs bimétalliques Re-Pd/TiO2 préparés ces deux méthodes reste différent. Le dépôt in situ de Re conduit à des catalyseurs bimétalliques prometteurs : SBDO = 73% avec 2% de rhénium déposé
The 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

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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.

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The objective of this study was to gain a better understanding of Opal Australian Paper’s (AP’s) waste streams as a potential substrate for biomanufacturing. Three low-value process streams were included in this study: Continuous Kraft Mill (CKM) weak black liquor (WBL), Neutral Sulphite Semi-Chemical (NSSC) WBL and WBL extracted from NSSC clean-pulp (CP). The primary focus of the study was to determine the chemical composition and extent of toxicity of these WBLs towards Actinobacillus succinogenes 130Z. This genetically engineered bacterium can produce a valuable platform chemical, succinic acid, using various carbohydrate sources. This project sought to increase knowledge of AP’s WBL and its suitability as a biomanufacturing substrate. Literature has been reviewed on various pre-treatment pathways for this waste stream, A. succinogenes 130Z and its effectiveness on producing succinic acid, and the analytical techniques that have been used to answer the project objectives. The effectiveness of pre-treating the NSSC and CP WBLs was measured using the following characteristics: (a) the colour content (specific absorbance) using UV-Vis spectroscopy, (b) indicative yields of several organic constituents through pyrolysis-gas chromatography-mass spectroscopy, (c) the atomic H/C and S/C ratios using an elemental analysis and (d) toxicity of the samples using a combination of semi-quantitative (plating trials) and quantitative (determination of minimum bactericidal concentration) techniques. The impact of an additional pre-treatment step of granular activated carbon for NSSC WBL was also researched here. InfraRed spectroscopy and toxicity analysis helped to conclude that CKM WBL is extremely toxic to Actinobacillus succinogenes 130Z and contained negligible amounts of residual sugar units. Characterising the NSSC and CP WBLs at the molecular level revealed the untreated WBLs are rich in lignin-derived methoxyphenols (up to 160 mg/kg) and contained low concentrations of elemental sulphur (up to approx. 1 mg/kg). Infra-red spectroscopy and gas chromatography indicated that the fermentable sugars in the WBLs were very low (< 1.2 mg/kg) even after pre-treatment. Both methoxyphenols and sulphur are known to be toxic to many bacteria and A. succinogenes 130Z could not tolerate more than 0.45 mg/ml (db, dry basis) and 0.78 mg/ml (db) of NSSC and CP WBLs respectively. Employing Amberlite® XAD7HP resins to pre-treat the NSSC and CP WBLs reduced their toxicity 2- to 5-fold, enabling the bacterium to survive in about 2.5 mg/ml (db) and 1 mg/ml (db) of NSSC and CP WBLs respectively. One possible reason for this is the significant reduction in lignin content afforded by this pre-treatment technique. These results conclude that AP’s WBLs are toxic and need to undergo pre-treatment prior to utilisation as a substrate for succinic acid production via fermentation.
Master by Research

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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.

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The objective of this study was to gain a better understanding of Opal Australian Paper’s (AP’s) waste streams as a potential substrate for biomanufacturing. Three low-value process streams were included in this study: Continuous Kraft Mill (CKM) weak black liquor (WBL), Neutral Sulphite Semi-Chemical (NSSC) WBL and WBL extracted from NSSC clean-pulp (CP). The primary focus of the study was to determine the chemical composition and extent of toxicity of these WBLs towards Actinobacillus succinogenes 130Z. This genetically engineered bacterium can produce a valuable platform chemical, succinic acid, using various carbohydrate sources. This project sought to increase knowledge of AP’s WBL and its suitability as a biomanufacturing substrate. Literature has been reviewed on various pre-treatment pathways for this waste stream, A. succinogenes 130Z and its effectiveness on producing succinic acid, and the analytical techniques that have been used to answer the project objectives. The effectiveness of pre-treating the NSSC and CP WBLs was measured using the following characteristics: (a) the colour content (specific absorbance) using UV-Vis spectroscopy, (b) indicative yields of several organic constituents through pyrolysis-gas chromatography-mass spectroscopy, (c) the atomic H/C and S/C ratios using an elemental analysis and (d) toxicity of the samples using a combination of semi-quantitative (plating trials) and quantitative (determination of minimum bactericidal concentration) techniques. The impact of an additional pre-treatment step of granular activated carbon for NSSC WBL was also researched here. InfraRed spectroscopy and toxicity analysis helped to conclude that CKM WBL is extremely toxic to Actinobacillus succinogenes 130Z and contained negligible amounts of residual sugar units. Characterising the NSSC and CP WBLs at the molecular level revealed the untreated WBLs are rich in lignin-derived methoxyphenols (up to 160 mg/kg) and contained low concentrations of elemental sulphur (up to approx. 1 mg/kg). Infra-red spectroscopy and gas chromatography indicated that the fermentable sugars in the WBLs were very low (< 1.2 mg/kg) even after pre-treatment. Both methoxyphenols and sulphur are known to be toxic to many bacteria and A. succinogenes 130Z could not tolerate more than 0.45 mg/ml (db, dry basis) and 0.78 mg/ml (db) of NSSC and CP WBLs respectively. Employing Amberlite® XAD7HP resins to pre-treat the NSSC and CP WBLs reduced their toxicity 2- to 5-fold, enabling the bacterium to survive in about 2.5 mg/ml (db) and 1 mg/ml (db) of NSSC and CP WBLs respectively. One possible reason for this is the significant reduction in lignin content afforded by this pre-treatment technique. These results conclude that AP’s WBLs are toxic and need to undergo pre-treatment prior to utilisation as a substrate for succinic acid production via fermentation.
Masters by Research

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Jacquel, Nicolas. « Synthesis and properties of polyesters based on poly(butylene succinate), a renewable polymer ». Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0127.

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Les polymères issus de la biomasse génèrent depuis quelques années un engouement certain puisqu’ils apparaissent comme de potentiels substituts aux polymères issus de l’industrie pétrolière. Parmi ces monomères récemment développés, l’acide succinique bio-sourcé a reçu une attention particulière notamment pour des applications dans le domaine des polyesters tels que le poly(butylène succinate). La présente thèse décrit la synthèse de ce polymère par estérification directe de l’acide succinique et du 1,4-butanediol dans un réacteur pilote de 7.5 L. Les principaux paramètres du procédé tels que l’excès de diol, la température de trans-estérification ainsi que la pureté de l’acide succinique ont été étudiés. Une attention particulière a été portée sur le choix du catalyseur (son type, la quantité utilisée …) afin d’observer son influence sur le procédé ainsi que sur la stabilité du polymère final. Puis différentes stratégies de modification du poly(butylene succinate) ont été testées pour améliorer à la fois sa mise en forme par extrusion gonflage et les propriétés des films obtenus. Dans ce but l’introduction d’agents de branchements, de silices nanométriques ainsi que des comonomères rigides a été étudiée
Polymers 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

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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.

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A biorefinery should ideally integrate biomass conversion processes to produce a range of fuels, power, materials, and chemicals from biomass. The term biorefinery is derived both from the raw material feedstock which is renewable biomass and also from the bioconversion processes often applied in the treatment and processing of the raw materials. Renewable sources are the basis of the alternative energy, fuels and compound obtained in a biorefinery-based way to meet the energy demand in a world where petrol fuels are becoming scarce and more expensive. The current biorefinery schemes are mainly based on hexose sugars (first generation) or lignocellulosic-based material (second generation) as feedstocks and depend on microbial cell factories for obtaining the products of interest. In most cases, the substrate utilization is not optimized jet: at the end of the process in addition to the main product, by-products such as huge quantity of lignin and some C5 sugars (deriving from incomplete utilization of lignocellulose) but also proteins (mainly the exhausted biomass at the end of the production) are still available. Focusing the attention on proteins, they are nowadays mainly absorbed as animal feed, but the quantities produced exceed the demand. Considering the implication related to GMO utilization and the increasing number of biorefineries, it can be stated that proteins could represent an interesting Abstract - 2 - “no-cost” starting material to produce more biofuel, bioproducts or biopower in a biorefinery-based way. This study has the aim to present some examples of production by using the protein side-stream of a biorefinery. In particular, we report the possible destiny of two aminoacids released from said proteins: glycine, to obtain butanol and isobutanol, and glutamate, to produce succinic acid. Butanol represents the most feasible alternative to gasoline, but, differently from ethanol, microbial fermentations are not enough developed to sustain the market demand. The natural producers, different species of the Gram positive group of Clostridia, present many and different limitations which are challenging the scientific communities in finding alternative hosts. Among the different alternative hosts, yeasts can present attractive features, being the most relevant the existence of industrial plants based on Saccharomyces cerevisiae fermentation for the production of ethanol. Up to now, in S. cerevisiae the production of butanol has been obtained by expressing heterologous genes from Clostridia. The best reported butanol titer is only 2.5 mg/L, probably mainly depending on problems related to the overexpression of heterologous prokaryotic enzymes. On the contrary, the isobutanol production is obtained at high level (0.63 g/L) in S. cerevisiae by using and optimizing an endogenous valine degradation pathway. We present an alternative and novel way to produce butanol and isobutanol using glycine as substrate, through a new identified and Abstract - 3 - biochemically characterized pathway. Starting from 15 g/L of glycine we have obtained 92 mg/L of butanol and 58 mg/L of isobutanol. Considering that the pathway has been just discovered and no optimization has been designed or applied, the obtained results has to be considered extremely positive. Since one of the most common stresses that microorganisms have to face during productions is the toxicity of the final product, we investigated also the possibility to use the glycine as protective agent for the cells. This idea originated from different studies that explain how the use of aminoacids, among which glycine, can help the cells to better respond to different stresses, such as high ethanol concentration and hydrogen peroxide. As never reported in literature, we have notably found that butanol causes a sort of oxidative stress, peroxidising the membrane lipids. Moreover, we have demonstrated that glycine can help the cells to better tolerate the presence of hydrogen peroxide, acetic acid, ethanol and butanol. The succinic acid occurs naturally in humans, animals, plants, and microorganisms as TCA cycle intermediate. Its use as a precursor to produce many important commodity chemicals used to make a wide assortment of products such as solvents, fiber and polymer production make it one of the most important relevant bulk chemicals. The microbial production of succinic acid via reductive TCA cycle using engineered Saccharomyces cerevisiae is nowadays on the market commercialised by Reverdia (Cassano Spinola, Italy). Abstract - 4 - Here we investigated the possibility to exploiting the glutamate degradation pathway through the γ-aminobutyric acid (GABA) intermediate as an additional way of obtaining succinate when a source of glutamate is feeded to the cells. Since this pathway, also called GAD/GABA shunt, is transcriptionally controlled, we transcriptionally up-regulated it through the constitutive overexpression of the involved genes, GAD1, UGA1 and UGA2. Even if the pathway was clearly overexpressed, as revealed by transcriptional analysis, the obtained amount of succinic acid did not reflect this modification. Further investigating the possible reason of that, we have demonstrated that, despite the higher transcription levels, the corresponding enzymatic activities of the pathway did not increased. We can argue that posttranslational regulations occur in the pathway, what at the moment impaired the initial aim of our work. However, the data add new and relevant information for the comprehension of the role and the regulation of this pathway in S. cerevisiae. It cannot be excluded that the production of succinic acid in yeasts might be in a future optimized by exploiting the GAD/GABA pathway, once it will be fully characterized. We have finally investigated the possibility to produce succinic acid in a strain of S. cerevisiae deleted in the gene encoding the enzyme glutamate synthase, GLT1. During this study we have tested different growing conditions, since the target gene of deletion is located in a critical node of the nitrogen sensing and utilization, which is related to cellular plasticity and adaptability in perturbed environment. We could demonstrate that Abstract - 5 - when cells are growing in low salts concentration medium, the deleted strain compared to wild type strain is able to accumulate more reduced products, such as succinic acid, malate/fumarate, glycerol and ethanol, indicating a sort of necessity to reduce the excess of NAD(P)H generated by the GLT1 deletion. Regarding this preliminary study, deeper investigations have to be performed to find a fine tuned way to intentionally redirect the metabolic flux and obtain the product of interest, which in turn could be succinic acid, but also malic or fumaric acid, or again ethanol, being this last the product that has the responsibility to prove that bio-based second generation processes can effectively and positively have an impact on our future society.

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Sacan, 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.

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ABSTRACT SYNTHESIS AND ELECTROCHROMIC PROPERTIES OF CONDUCTING POLYMERS OF SUCCINIC ACID BIS-(2-THIOPHEN-3-YL-ETHYL) ESTER AND THEIR USE IN ELECTROCHROMIC DEVICES Saç
an, 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.

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Delhomme, Clara [Verfasser], Dirk [Akademischer Betreuer] Weuster-Botz et 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.

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Xiberras, Joeline [Verfasser], Elke [Akademischer Betreuer] Nevoigt, Elke [Gutachter] Nevoigt, Sebastian [Gutachter] Springer et 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.

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ALMEIDA, 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.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-10-22T16:54:02Z No. of bitstreams: 0
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Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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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.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
This 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.

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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.

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A deficiência da semi-aldeído succínico desidrogenase (SSADH) e a tirosinemia tipo II caracterizam-se pela presença de elevadas concentrações teciduais e plasmáticas de ácido γ-hidroxibutírico (GHB) e tirosina, respectivamente. Tanto os pacientes afetados pela deficiência da SSADH quanto aqueles com tirosinemia tipo II apresentam sinais e sintomas neurológicos. Embora os mecanismos responsáveis pela disfunção neurológica sejam pouco conhecidos, sabe-se que podem estar relacionados ao acúmulo de GHB e tirosina e seus possíveis efeitos tóxicos sobre o sistema nervoso central (SNC). Considerando ainda que o estresse oxidativo parece estar envolvido em diversas doenças ou alterações patológicas que afetam o SNC, os efeitos do GHB e da L-tirosina sobre vários parâmetros de estresse oxidativo foram investigados em homogeneizados de córtex cerebral de ratos jovens. Os efeitos in vivo do GHB, ou de seu precursor 1,4-butanodiol, foram semelhantes. Ambos mostraram comprometimento das defesas antioxidantes não-enzimáticas e indução da lipoperoxidação. Os efeitos in vitro e in vivo da L-tirosina, por sua vez, foram diferentes: in vitro, a L-tirosina provocou dano oxidativo ao DNA, diminuiu as defesas antioxidantes não-enzimáticas e enzimáticas e alterou o estado redox (razão SH/SS), enquanto que a administração aguda de L-tirosina causou dano oxidativo a lipídios e proteínas, modificou a razão SH/SS, diminuiu as defesas antioxidantes não-enzimáticas e estimulou a atividade da glicose-6-fosfato desidrogenase. Esses resultados sugerem que o GHB e a L-tirosina são capazes de promover o estresse oxidativo em córtex cerebral de ratos jovens. Desta forma, caso esses mesmos efeitos ocorrerem em seres humanos, é provável que o estresse oxidativo seja um dos mecanismos responsáveis pela neuropatologia característica da deficiência da SSADH e tirosinemia tipo II.
Succinic 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.

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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/.

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Nessa pesquisa avaliou-se a produção fermentativa de hidrogênio e ácidos orgânicos a partir do bagaço de cana-de-açúcar (BCA) usado como substrato em reatores em batelada. Três condições de pré-tratamento (hidrotérmico, autoclave e hidrotérmico mais autoclave) do BCA e condição in natura foram avaliadas a fim de favorecer a produção de hidrogênio. Verificou-se produção molar de hidrogênio de 3,79 mmol/L, 3,47 mmol/L, 1,67 mmol/L e 1,01 mmol/L para BCA autoclavado, BCA in natura, BCA pré-tratado em sistema hidrotérmico e BCA pré-tratado em sistema hidrotérmico seguido de autoclave, respectivamente. A partir desses valores, optou-se por usar o BCA autoclavado como substrato para otimização da produção de hidrogênio e ácidos orgânicos a partir de metodologias de delineamento do composto central e superfície de resposta. Foram monitorados 10 reatores em batelada (R1 a R10), em triplicatas, com diferentes concentrações de substrato (0,8 a 9,2 g/L) e pH (de 4,6 a 7,4). A maior produção de hidrogênio (24,1 mmol/L) e 6,4 g/L de ácidos orgânicos foram obtidos em R4 (8,0 g BCA/L e pH 7,0). Os açúcares glicose, arabinose, xilose, manose e galactose foram observados ao longo do tempo de operação em todos os reatores, sendo arabinose observado em maior concentração nas condições dos reatores R3 (8,0 g BCA/L e pH 5,0) e R8 (5,0 g BCA/L e pH 7,4), respectivamente, 1.415,3 e 1.372,5 mg/L. A produção de hidrogênio foi concomitante à formação de ácidos orgânicos, principalmente butírico (de 14,6 a 33,8% em R1 e R6, respectivamente) e succínico (de 19,5 a 26,4% em R3 e R9, respectivamente). Os dois fatores analisados, concentração de substrato e pH, exerceram efeitos significativos na produção de hidrogênio, ácido butírico e succínico. A partir dos resultados obtidos com o planejamento fatorial, foi possível verificar que o valor máximo de produção de hidrogênio estimado pelo modelo foi de 23,10 mmol/L, para 7,0 g BCA/L e pH 7,2. O valor obtido no experimento de otimização (Rotm) foi de 19,84 mmol/L, com grau de precisão do modelo de 85,9% para produção de hidrogênio a partir de BCA autoclavado. Sequenciamento massivo via plataforma Illumina (Miseq) foi realizado para a identificação de bactérias do reator do ponto central, (R9, 5,0 g BCA/L e pH 6,0), do reator otimizado (Rotm, 7,0 g BCA/L e pH 7,2), de amostras do BCA autoclavado e inóculo. No inóculo foram identificadas principalmente bactérias semelhantes a Clostridium bifermentans (62,69% de abundância relativa), Bacillus coagulans (31,67%) e Enterobacter aerogenes (2,72%). No BCA foram identificadas bactérias semelhantes a C. bifermentans (31,91%), C. cellobioparum (32,29%), C. cellulolyticum (5,69%), C. sartagoforme (14,63%) e Paenibacillus spp. (11,67%). Estas bactérias não foram favorecidas sob as condições impostas em R9 (5,0 g BCA/L e pH 6,0) e Rotm (7,0 g BCA/L e pH 7,2), uma vez que a abundância relativa das bactérias nas amostras dos reatores foram completamente diferentes. Em R9, bactérias semelhantes a Lactobacillus paracasei e Escherichia hermannii foram as principais identificas com 37,50 e 34,32% de abundância relativa, respectivamente. Em Rotm, as principais bactérias identificadas foram semelhantes a Bacteroides sp. e Enterobacter aerogenes, com 37,35 e 27,72% de abundância relativa, respectivamente. Assim, as populações bacterianas, bem como a produção de metabólitos, foram alteradas em função das condições impostas; ou seja, concentração de BCA, pH em reatores em batelada com BCA autoclavado como substrato.
This 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.

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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.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This 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.

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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.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Rice 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.

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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.

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Mizzi, 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.

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Le couplage fonctionnel des opérations de séparation et de réaction ainsi que les bio-procédés sont deux axes de recherche largement explorés. Cependant, l’industrie du génie des procédés a du mal à se tourner vers des technologies de ce type car il demeure un réel manque de connaissances et d’outils de conception pour ce genre de procédés. Une méthodologie de conception générale pour l'extraction liquide-liquide réactive est introduite dans cette étude. Elle est composée de trois étapes différentes: l'analyse de faisabilité, la synthèse ou dimensionnement du procédé et la validation par simulation. Cette méthodologie conduit à des paramètres structuraux et opératoires de la colonne étudiée à partir seulement des informations concernant le comportement physico-chimique du système étudié, en exploitant les équations d’équilibre chimique et entre phase ainsi que les bilans matières. Les résultats de cette méthode sont un bon point de départ pour une étude d'optimisation ou d'un processus de calcul d'investissement. Cette méthodologie a été appliquée à différentes études de cas: regroupant deux stratégies différentes d'extraction avec plusieurs solvants pour récupérer l'acide succinique dans un milieu de fermentation

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Kaboré, 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.

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L'acide succinique est une molécule linéaire, bi-fonctionnelle qui possède de nombreuses applications alimentaires, chimiques et pharmaceutiques etc. Les connaissances de la régulation des voies métaboliques d’organismes d’intérêt industriel, le génie génétique et le génie des procédés ont permis à des microorganismes recombinants (C. glutamicum) de produire jusqu'à 100 g.L-1 de succinate avec des rendements intéressants. C. glutamicum est largement connu comme l'un des meilleurs producteurs industriels de nombreux acides aminés (glutamate, lysine etc.). Cependant, des études de C. glutamicum ont démontré sa capacité à produire plusieurs acides organiques (succinate, lactate, acétate, etc.). Au cours de ce travail, nous avons supprimé le gène ldhA de C. glutamicum en utilisant le plasmide pk19mobsacBΔldhA. Nous avons démontré que la délétion de ce gène n’avait pas d’incidence sur la capacité de croissance de la bactérie. Par ailleurs, nous avons étudié les effets de l’oxygénation sur la réponse physiologique de C. glutamicum 2262ΔldhA à travers des expériences de cultures en fioles en verre lisses en imposant différentes conditions de kLa. Les résultats ont montré que des faibles kLa (<33 h-1) favorisaient la production d’acides organiques tandis que les kLa élevés amélioraient surtout l’accumulation de la biomasse. Nous avons également mis en œuvre un procédé de production très efficace avec une phase de transition aérobiose-anaérobiose basée sur la régulation de la concentration en oxygène dissous. Avec ce procédé, 327 mM de succinate avec un rendement de 0,94 mole par mole de glucose ont pu être produits avec le mutant ΔldhA. En outre, nous avons vérifié l’efficacité de ce nouveau procédé en l’appliquant à la souche sauvage qui normalement produit 10 fois plus de lactate que de succinate. Ces résultats ont montré une production de 793 mM (94 g.L-1) de succinate et 785 mM (71 g.L-1) de lactate. Ils soulignent ainsi, l'importance de la phase de transition aérobiose-anaérobiose lors des procédés de production de succinate par des bactéries aérobie facultatif. Enfin, des expériences en système bi-étagé ont montré que C. glutamicum 2262 pouvait s’adapter très facilement aux gradients et hétérogénéités en oxygène dissous dans les cultures à grande échelle
Succinic 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

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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.

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The Square Kilometre Array (SKA) is a multibillion and a multinational science project to build the world’s largest and most sensitive radio telescope. For a very large field of view, the combined collecting area would be one square kilometre (or 1, 000, 000 square metre) and spread over more than 3,000 km wide which will require a massive count of antennas (thousands). Each of the antennas contains hundreds of low noise amplifier (LNA) circuits. The antenna arrays are divided into low, medium and high operational frequencies and located at different positions to boost up the telescope’s scanning sensitivity.The objective of this work was to develop and fabricate fully on-chip LNA circuits to meet the stringent requirements for the mid-frequency array from 0.4 GHz to 1.4 GHz of the SKA radio astronomy telescope using Monolithic Microwave Integrated Circuit technology (MMIC). Due to the number of LNA reaching figures of millions, the fabricated circuits were designed with the consideration for low cost fabrication and high reliability in the receiver chain. Therefore, a relaxed optical lithography with Lg = 1 µm was adopted for a high yield fabrication process.Towards the fulfilment of the device’s low noise characteristics, a large number of device designs, fabrication and characterisation of InGaAs/InAlAs/InP pHEMTs were undertaken. These include optimisations at each critical fabrication steps. The device’s high breakdown and very low gate leakage characteristics were further improved by a combination of judicious epitaxial growth and manipulation of materials’ energy gaps. An attempt to increase the device breakdown voltage was also employed by incorporating Field Plate structure at the gate terminal. This yielded the devices with improvements in the breakdown voltage up to 15 V and very low gate leakage of 1 µA/mm, in addition to high transconductance (gm) characteristic. Fully integrated double stage LNA had measured NF varying from 1.2 dB to 1.6 dB from 0.4 GHz to 1.4 GHz, compared with a slightly lower NF obtained from simulation (0.8 dB to 1.1 dB) across the same frequency band.These are amongst the attractive device properties for the implementation of a fully on-chip MMIC LNA circuits demonstrated in this work. The lower circuit’s low noise characteristic has been demonstrated using large gate width geometry pHEMTs, where the system’s noise resistance (Rn) has successfully reduced to a few ohms. The work reported here should facilitate the successful implementation of rugged low noise amplifiers as required by SKA receivers.

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Van, Heerden Carel Daniel. « Continuous succinic acid fermentation by Actinobacillus succinogenes ». Diss., 2012. http://hdl.handle.net/2263/26922.

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LI, YUAN-SHUAN, et 李芫瑄. « The study of catalysts for succinic acid hydrogenation ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8c2gb2.

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碩士
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%.

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Wang, Jun-Yue, et 王俊岳. « Catalyst studies for the esterification of succinic acid and butyric acid ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/84395108937094009010.

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碩士
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.

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Kaul, Arvind. « Remediation of heavy-metal contaminated soils using succinic acid ». Thesis, 1992. http://hdl.handle.net/1957/37052.

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Succinic acid, a low molecular weight dicarboxylic acid was used to leach out heavy metals from Willamette Valley soil (contaminated separately with lead, copper, and zinc) in form of water-soluble organo-metal complexes. The research tasks included developing synthetic contaminated soils representative of those found at Superfund sites and making heavy metal adsorption and desorption studies. Fixed amounts of single-metal contaminated soil were treated with succinic acid under varying conditions of pH and organic ligand concentration. Based on the total metal mobilized into the aqueous phase, the optimum values of pH and organic acid were established for each metal. Since the direct determination of all species solubilized by the organic acid solution was not possible, a computer speciation program called MICROQL was used to determine the concentration of metal species in solution containing several metals and potential ligands. The results indicate that succinic acid is capable of significantly altering the partitioning of metals between the soil and the aqueous phase. Higher concentrations of the organic acid resulted in higher removal of metal from the soil. In case of lead and copper, low pH (3.5) succinic acid flushing solution was found to be the most effective, while a pH range of 4.5-5.5 was deemed optimum for zinc. The results also established that the extent of removal of any metal depended not only upon the the stability constant of the organo-metal complex, but also on its mode of retention within the soil.
Graduation date: 1993

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Chen, Cheng-heng, et 陳政宏. « Modeling and Optimization of the Production of Succinic Acid ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/05720843693249943503.

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碩士
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.

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Macedo, Alfredo Pina de. « Production of succinic acid from eucalyptus kraft pulp hydrolysates ». Master's thesis, 2019. http://hdl.handle.net/10773/30291.

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Succinic acid is an important “building block” to the chemical and polymer industries, being the base molecule for the synthesis of a vast array of products. Despite its biological origin, the succinic acid was initially produced by the petrochemical industry, having high environmental impacts like the release of CO2. Nowadays, with the increasing development of biotechnology and due to environmental and economic concerns, there is a significant production of succinic acid by bioprocesses, within the biobased industry. The biological production of succinic acid includes the consumption of CO2 and contributes for reducing the emissions. Moreover, it is well documented the possibility of using agro-industrial wastes such as lignocellulosic, as feedstocks to produce succinic acid. From those it is possible to evidence the residues originated by the pulp and paper industry, namely wood residues, for which the kraft process could be used as a pre-treatment candidate for bioprocesses. The aim of this work was to produce succinic acid from cellulose pulp obtained by delignification of Eucalyptus globulus wood through kraft cooking. The first step was an enzymatic hydrolysis of the celluloses and hemicelluloses to produce a hydrolysate composed by the respective monosaccharides. This hydrolysate was fermented by the bacterium Actinobacillus succinogenes, the process biocatalyst operated under batch and fed-batch conditions. Using the kraft wood pulp hydrolysate, it was possible to attain a succinic acid concentration of 19.93 g/L, with a yield and productivity of 0.399 g/L.h and 0.331 gsuccinic acid/gsugars, respectively. These values were improved with the addition of magnesium carbonate, however, this salt also led to the production of a higher concentration of byproducts. In the fed-batch fermentation, it was verified that the lactic acid production surpassed the succinic acid production. Nonetheless, those results further evidenced the possibility of exploiting this fed-batch operation to produce both succinic and lactic acid. This study served as a reference for future studies fed with wood residues, in order to their integration into a pulp and paper biorefinery working according to the Circular Economy model.
O 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

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Tzu-YuLi et 李姿諭. « Strategies for Effective Recovery of Succinic Acid from Fermentation Broth ». Thesis, 2017. http://ndltd.ncl.edu.tw/handle/28jag3.

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Hsu, Hua-Ju, et 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.

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碩士
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.

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Yang, Yu-Jui, et 楊育睿. « Catalytic Benzylation of Succinic Acid Disodium Salt by Phase-transfer catalysis ». Thesis, 2006. http://ndltd.ncl.edu.tw/handle/94846048486663193635.

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碩士
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.

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49

YU, CHENG-HONG, et 洪淯誠. « Spearation of succinic acid through liquid membrane supported by PVA film ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/18315201929623507769.

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碩士
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.

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50

Lee, Lin-En, et 李臨恩. « Study of the process for recovering Succinic-acid from fermentation broths ». Thesis, 2015. http://ndltd.ncl.edu.tw/handle/92410596762864529078.

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碩士
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.

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Thèses sur le sujet « Acidi succinici »

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