Log in

Relevant bibliographies by topics / Hydrolysis lignin / Dissertations / Theses

To see the other types of publications on this topic, follow the link: Hydrolysis lignin.

Dissertations / Theses on the topic 'Hydrolysis lignin'

Author: Grafiati

Published: 28 May 2022

Last updated: 30 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Hydrolysis lignin.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Madikane, Mzekelo. "Biosulphidogenic hydrolysis of lignin and lignin model compounds." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1003976.

Full text

Abstract:

Lignin degradation under biosulphidogenic conditions has not been extensively reported in the literature. Although aerobic degradation of lignin is well documented, anaerobic biodegradation has focused mainly on methanogenic systems with biosulphidogenic systems receiving less attention. Sulphate reducing bacteria are known to generate moderately high levels of both sulphide and alkalinity at room temperatures, and these conditions draw some comparison with the Kraft pulping process. In the Kraft pulping process, lignin is degraded chemically at ±170°C under high sulphide and alkaline conditio

APA, Harvard, Vancouver, ISO, and other styles

2

Roberts, Virginia Marie. "Homogeneous and heterogeneous catalyzed hydrolysis of lignin." kostenfrei, 2008. http://mediatum2.ub.tum.de/doc/652904/652904.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Tan, Xin. "Effect of Organosolv Lignin and Extractable Lignin on Enzymatic Hydrolysis of Lignocelluloses." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613752000022518.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Huron, Maïté. "Modélisation cinétique de l'hydrolyse enzymatique de biomasse lignocellulosique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI044.

Full text

Abstract:

Le bioéthanol 2G est une alternative viable aux carburants d'origine fossile et de nombreux projets industriels travaillent aujourd'hui à sa mise au point. Il est produit par fermentation des sucres contenus dans la biomasse lignocellulosique (résidus forestiers, résidus agricoles, cultures dédiées…). Ces sucres sont extraits de la biomasse lors d'une étape d'hydrolyse enzymatique, qui fait actuellement partie des points importants à optimiser pour rendre le procédé plus compétitif.L'objectif de cette thèse était de mieux définir les mécanismes mis en jeu lors de l'hydrolyse enzymatique de la

APA, Harvard, Vancouver, ISO, and other styles

5

Goldstein, Steven Alan. "Determination of the degree of condensation of lignin from solvent pulping and steam hydrolysis of tulip poplar." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/20949.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Mirshokraie, S. Ahmad (Seyed Ahmad). "Reactions of a-substituted non-phenolic lignin model compounds under alkaline hydrolysis conditions." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75783.

Full text

Abstract:

Side-chain ether groups in lignin model compounds of the general structure 1-(3$ sp prime$,4$ sp prime$-dimethoxyphenyl)-1,2-diaryloxyethane exhibited hydrolytic cleavage (the extent depending on the substituents on the 1-aryloxy groups) in aqueous 2N NaOH at 150$ sp circ$C (i.e. under wood pulping conditions). The level of hydrolysis increased in phenylpropane models (i.e. with $ gamma$-CH$ sb2$OH). Thus the commonly accepted generalization that 1,2-diethers of 3$ sp prime$,4$ sp prime$-dimethyoxyphenylpropane are stable in hot alkali is valid only for 1-alkoxy compounds. The newly observed h

APA, Harvard, Vancouver, ISO, and other styles

7

Nakagame, Seiji. "The influence of lignin on the enzymatic hydrolysis of pretreated biomass substrates." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/29896.

Full text

Abstract:

During the “enzymatic hydrolysis of the cellulose” component of the overall lignocelluloses-to-bioethanol process, lignin has been shown to be a very influential factor, acting as both a physical barrier and limiting hydrolysis through the adsorption of cellulases. Although hydrophobic, electrostatic and hydrogen bonding interactions between lignin and cellulases have been suggested to influence the hydrolysis efficiency, comparative studies using isolated lignins from different types of biomass which have been pretreatment in different ways have not been done. To gain a better understanding o

APA, Harvard, Vancouver, ISO, and other styles

8

Stevens, Gary Grant. "An investigation of the microbial hydrolysis of the lignin carbohydrate complex of grasses." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/53722.

Full text

Abstract:

Thesis (MSc)--University of Stellenbosch, 2004.<br>ENGLISH ABSTRACT: The microbial degradation of the lignin carbohydrate complex of plant material is only partially understood. Lignin carbohydrate complex was extracted from wheat straw and subsequently analysed. An adjustment to the standard protocol was required to increase the amount of lignin carbohydrate complex extracted from wheat straw. Characterization of the lignin carbohydrate complex after trifluoacetic acid hydrolysis was done by capillary electrophoresis. HPLC proved ineffective, as baseline separation could not be achieved

APA, Harvard, Vancouver, ISO, and other styles

9

Hu, Fan. "Pseudo-lignin chemistry in pretreatment of biomass for cellulosic biofuel production." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52996.

Full text

Abstract:

Pseudo-lignin, which can be broadly defined as aromatic material that yields a positive acid-insoluble (Klason) lignin value, has been reported to generate from biomass polysaccharides during dilute acid pretreatment (DAP). To investigate the fundamental chemistry of pseudo-lignin, a series of state-to-art analytical techniques including GPC, FT-IR and ¹³C NMR were applied to characterize pseudo-lignin extracted from poplar α-cellulose and holocellulose after DAP. The results showed that pseudo-lignin is polymeric (Mn ~ 1000 g/mol; Mw ~ 5000 g/mol) and consists of carbonyl, carboxylic, aromati

APA, Harvard, Vancouver, ISO, and other styles

10

Marabezi, Karen. "Estudo sistemático das reações envolvidas na determinação dos teores de lignina e holocelulose em amostras de bagaço e palha de cana-de-açúcar." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-07102009-100309/.

Full text

Abstract:

Os métodos analíticos empregados atualmente para a caracterização química de materiais lignocelulósicos foram desenvolvidos para a madeira e são empregados com pequenas modificações ao bagaço e à palha da cana-de-açúcar. A não existência de metodologia específica para estes materiais leva a obtenção de resultados inadequados e dificultam tanto o planejamento quanto a interpretação de resultados. Sendo assim, o objetivo principal deste trabalho é desenvolver metodologias analíticas específicas para a caracterização química da palha e do bagaço de cana-de-açúcar. A determinação de lignina foi es

APA, Harvard, Vancouver, ISO, and other styles

11

Yue, Conghui. "Bridging the Gap in Biomass Conversion: Understanding Enzymatic Hydrolysis of Cellulose and Hydrogenative Degradation of Lignin at the Molecular Level." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627661055938336.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Kim, Tae Hyun Lee Yoon Y. "Bioconversion of lignocellulosic material into ethanol pretreatment, enzymatic hydrolysis, and ethanol fermentation /." Auburn, Ala., 2004. http://repo.lib.auburn.edu/EtdRoot/2004/FALL/Chemical_Engineering/Dissertation/KIM_TAE_24.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Reinoso, Felipe Andres Montoya. "Aplicação de uma mistura de enzimas para hidrolisar bagaço de cana-de-açúcar pré-tratado com sulfito." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/97/97131/tde-24032015-151715/.

Full text

Abstract:

O cultivo da cana-de-açúcar é uma das atividades agrícolas mais importantes no Brasil, produzindo após a moagem o caldo, utilizado para a produção de açúcar e etanol, e o bagaço, resíduo lignocelulósico. O bagaço é recalcitrante à hidrólise enzimática, em parte pela baixa porosidade, resultante do recobrimento das fibrilas de celulose com lignina e hemicelulose. Neste estudo, o bagaço foi pré-tratado com sulfito alcalino nas concentrações de 2,5% de NaOH e 5% de Na2SO3 versus 5% de NaOH e 10% de Na2SO3 para produzir substratos para hidrólise enzimática. Ambos pré-tratamentos produziram substra

APA, Harvard, Vancouver, ISO, and other styles

14

Gupta, Rajesh Lee Yoon Y. "Alkaline pretreatment of biomass for ethanol production and understanding the factors influencing the cellulose hydrolysis." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Chemical_Engineering/Dissertation/Gupta_Rajesh_7.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Jiang, Feng. "Effects of the Non-ionic Surfactant Tween 80 on the Enzymatic Hydrolysis of Model Cellulose and Lignocellulosic Substrates." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/77223.

Full text

Abstract:

Non-ionic surfactants are known to enhance the biochemical conversion of lignocellulosic (LC) biomass to bioethanol. Their mechanisms of action, however, are incompletely understood. This research was conducted to elucidate the effects of the non-ionic surfactant Tween 80 on the enzymatic hydrolysis of cellulose and LC substrates. Model cellulose substrates were prepared from cellulose nanocrystals (CNCs) obtained by sulfuric acid hydrolysis of wood pulp. Two methods were developed for the removal of the sulfate groups on the CNCs, resulting from the use of sulfuric acid in their preparation.

APA, Harvard, Vancouver, ISO, and other styles

16

Dunn, Kameron Gary. "Conversion of sugar cane lignin into aromatic products and fractionation of products for industrial use." Thesis, Queensland University of Technology, 2014.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

17

Costa, Thales Henrique de Freitas. "Avaliação da recalcitrância de diferentes regiões oriundas de entrenós de cana-de-açúcar em híbridos com teores variados de lignina." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/97/97131/tde-28082013-094005/.

Full text

Abstract:

O presente trabalho avaliou a recalcitrância de diferentes regiões do entrenó de plantas de cana-de-açúcar que apresentavam teores contrastantes de lignina total. As amostras com baixo teor de lignina corresponderam aos híbridos experimentais denominados de H58 e H89, com 18,6% e 16,8% de lignina, respectivamente. As amostras com elevado teor de lignina corresponderam ao híbrido H140 e a um cultivar comercial (CR), com 21,5% e 24,5% de lignina, respectivamente. De cada cana foram obtidas quatro regiões distintas dos entrenós: medula, interface medula-córtex, córtex e fração externa (epiderme m

APA, Harvard, Vancouver, ISO, and other styles

18

Philippini, Rafael Rodrigues. "Variedades híbridas de bagaço de cana-de-açúcar: caracterização química e hidrólise enzimática em condições de pré-tratamento difrenciadas." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-27082013-105559/.

Full text

Abstract:

O presente trabalho teve como objetivo, a caracterizacao da composicao quimica de diferentes variedades de bagaco de cana-de-acucar (CTC-9; CT99-1906; SP81-3250; RB86-7515 e CT99-1902), e posterior hidrolise enzimatica para averiguacao de acucares redutores e sacarificacao da biomassa. As analises composicionais foram realizadas utilizando biomassa nas condicoes in natura, celulignina e polpa celulosica. As condicoes de pre-tratamento das amostras para hidrolise com acido sulfurico diluido (relacao s/l: 1,5:10; temperatura: 150 °C; concentracao acida: H2SO4 2% m/v; tempo: 30 minutos); e deslig

APA, Harvard, Vancouver, ISO, and other styles

19

Srinivasan, Narayanan. "Pretreatment of Guayule Biomass Using Supercritical CO₂-based Method for Use as Fermentation Feedstock." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1289782016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Friend, Debora Ferreira Laurito. "Pré-tratamento sulfito alcalino e hidrólise enzimática de bagaços de cana-de-açúcar com diferentes composições químicas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/97/97131/tde-16102013-153631/.

Full text

Abstract:

Para diminuir o consumo dos combustíveis fósseis, que são os principais agentes intensificadores do efeito estufa, muitas pesquisas estão sendo realizadas para aumentar a produção de etanol, com ênfase no etanol produzido a partir de materiais lignocelulósicos. Dentre as etapas necessárias para esse processo, uma delas é a hidrólise enzimática da celulose a monômeros solúveis. No entanto, a parede celular das plantas é recalcitrante e de difícil acesso às enzimas. Diante disto, neste trabalho propôs-se tratar bagaços de cana-de-açúcar com diferentes concentrações de solução sulfito em meio alc

APA, Harvard, Vancouver, ISO, and other styles

21

Siqueira, Germano Andrade. "Hidrólise enzimática do bagaço de cana-de-açúcar deslignificado e distribuição topoquímica da lignina e dos ácidos hidroxicinâmicos na parede celular." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-27092012-121133/.

Full text

Abstract:

O bagaço de cana-de-açúcar é um material rico em celulose, molécula que pode ser convertida enzimaticamente em glicose pela ação de celulases. No entanto, no bagaço, a celulose está associada à hemicelulose e à lignina, componentes que limitam a sua digestibilidade enzimática. A lignina é o principal limitante da hidrólise da celulose, reduzindo a acessibilidade das enzimas celulolíticas. A hemicelulose também limita a ação das celulases e a presença de ácidos hidroxicinâmicos, como ferúlico e cumárico contribuem para reduzir os níveis de hidrólise. Nesse trabalho, o bagaço de cana-de-açúcar f

APA, Harvard, Vancouver, ISO, and other styles

22

RIBEIRO, MARCIA A. "Pré-tratamento do bagaço de cana utilizando o processo de oxidação avançada por feixe de elétrons para hidrólise enzimática da celulose." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10207.

Full text

Abstract:

Made available in DSpace on 2014-10-09T12:36:01Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T13:59:36Z (GMT). No. of bitstreams: 0<br>Tese (Doutoramento)<br>IPEN/T<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

APA, Harvard, Vancouver, ISO, and other styles

23

Mendes, Fernanda Machado. "Digestibilidade enzimática do bagaço de cana-de-açucar tratado quimio-mecanicamente." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-27092012-111006/.

Full text

Abstract:

Métodos que convertem o bagaço de cana-de-açúcar em açúcares fermentescíveis são geralmente compostos por duas etapas principais: pré-tratamento para degradar a estrutura da planta e uma etapa de hidrólise enzimática ou química para converter as cadeias poliméricas em açúcares. Cada tecnologia de pré-tratamento tem um mecanismo diferente de ação sobre a estrutura do bagaço induzindo modificações físicas e/ou químicas, que são necessárias devido a presença de hemicelulose e lignina na parede celular da planta, o que impede o acesso das celulases nas partes internas do substrato. No presente tra

APA, Harvard, Vancouver, ISO, and other styles

24

Siqueira, Germano Andrade. "Efeito da lignina de bagaços de cana-de-açúcar pré-tratados na hidrólise enzimática da celulose." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/97/97131/tde-05082015-152627/.

Full text

Abstract:

No presente trabalho, avaliou-se o efeito limitante da lignina residual de bagaço de cana submetido a diferentes pré-tratamentos na hidrólise da celulose. O bagaço foi submetido a cinco pré-tratamentos: NaOH (5%), Na2SO3/NaOH (10%/5%), H2SO4 (0,75%), NaHSO3/H2SO4 (5%/0,75%) e explosão a vapor catalisada por SO2 (3%). Os pré-tratamentos resultaram em bagaços com diferentes composições químicas, sendo que os tratamentos alcalinos favoreceram a solubilização de lignina e os tratamentos ácidos favoreceram a solubilização de hemicelulose. Os bagaços tratados com Na2SO3/NaOH e por explosão a vapor r

APA, Harvard, Vancouver, ISO, and other styles

25

Costa, Adriana GuimarÃes. "EstratÃgias de PrÃ-Tratamentos para a ProduÃÃo de Metano a Partir dos ResÃduos LignocelulÃsicos dos BiocombustÃveis." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=10208.

Full text

Abstract:

nÃo hÃ<br>Este trabalho teve como objetivos avaliar a biodegradabilidade anaerÃbia e o potencial de produÃÃo de metano (PPM) de trÃs resÃduos lignocelulÃsicos proveniente da cadeia produtiva do biocombustÃvel (fibra do mesocarpo do dendÃ - FMD), (bagaÃo de cana-de-aÃÃcar - BCA) e lÃnter de algodÃo tipo 4 - (LA4). Para tanto, empregou-se trÃs diferentes tipos de prÃ-tratamentos fÃsico-quÃmicos (hidrÃlise hidrotÃrmica, hidrÃlise Ãcida e hidrÃlise alcalina), onde foram usados diversos tempos de reaÃÃo, temperaturas, razÃes massa/volume e concentraÃÃes de Ãcido ou Ãlcali, de forma a buscar o melho

APA, Harvard, Vancouver, ISO, and other styles

26

Tatli, Emre. "Pretreatment Of Peanut Shells For Co-production Of Glucose And Concrete Admixture." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615535/index.pdf.

Full text

Abstract:

This thesis work aims the ionic liquid pretreatment of peanut shells for co-production of glucose as fermentable sugar and lignin, considering a multi product perspective. The effects of ionic liquid type and pretreatment time period on the sugar and lignin yields were investigated, as the particle size and temperature parameters were determined in the preliminary studies. Peanut shells were pretreated at constant temperature, 150 oC, for 5, 15 and 30 minutes with 1-ethyl-3-methylimidazolium acetate and for 15, 30 and 60 minutes with 1-ethyl-3-methylimidazolium chloride. The pretreated peanut

APA, Harvard, Vancouver, ISO, and other styles

27

Lindén, Pär. "The origin of fibre charge in chemical pulp." Thesis, KTH, Skolan för kemivetenskap (CHE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146628.

Full text

Abstract:

Chemical components in wood contain multiple anionic groups, including carboxyl groups and hydroxyl groups. During kraft cooking and bleaching, such structures are also formed, degraded or modified by the action of reactions both deliberate and unwanted. It has previously been found by Laine that anionic groups with pKa values of 3.3 and 5.5 can explain the observed anionic charge on chemical fibres, corresponding to carboxylic acids on hemicelluloses as well as oxidized lignin structures, respectively. It has further been found that most of the fibre charge can be accounted for through the co

APA, Harvard, Vancouver, ISO, and other styles

28

Ващук, В. В. "Удосконалення методів зменшення техногенного забруднення довкілля відходами полістиролу". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2012. http://elar.nung.edu.ua/handle/123456789/1769.

Full text

Abstract:

Дисертація присвячена питанням зниження антропогенного забруднення довкілля побутовими відходами виробів з полістиролу та залишковими агрохімікатами шляхом утилізації відпрацьованого пластику у технологіях виробництва капсульованих мінеральних добрив. Проведено дослідження біодеструкції полістиролу в суміші із природним полісахаридом, отримано математичну залежність ступеня розкладу полістиролу у грунті в залежності від вмісту полісахариду та вологості середовища. Удосконалено плівкоутворюючу композицію для капсулювання гранульованих мінеральних добрив, що містить відходи полістиролу та

APA, Harvard, Vancouver, ISO, and other styles

29

Abdou, Alio Maarouf. "Production de bioéthanol à partir d'une biomasse lignocellulosique multi-ressources locale par prétraitement Organosolv et hydrolyse enzymatique." Thesis, Université Clermont Auvergne‎ (2017-2020), 2020. http://www.theses.fr/2020CLFAC061.

Full text

Abstract:

Dans un contexte de transition énergétique et de lutte contre le dérèglement climatique, la production de bioéthanol de 2ème génération est reconnue comme une voie prometteuse pour réduire notre dépendance aux combustibles fossiles. Mon travail de thèse a porté sur l’étude de faisabilité de la production de bioéthanol de 2ème génération à partir d’un substrat végétal de type « déchet bois », constitué de sciure récupérée auprès d’une scierie locale. Cette sciure est un mélange de quatre espèces de bois de types résineux, représentatives des essences locales. L’analyse chimique de ce déchet a m

APA, Harvard, Vancouver, ISO, and other styles

30

Uwinez, Clarisse. "Intensification of lignocellulosic bioethanol production process using multi-staged membrane bioreactors." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-21635.

Full text

Abstract:

The exploitation of lignocellulosic materials with the aim of producing high value-added products will potentially counteract concerns related to the depletion of fossil resources or exponential population growth. Bioethanol produced from lignocellulosic agriculture residue exhibits promising alternative to the petroleum-based fossil fuel which reduces net emission of greenhouse gases (GHG). But, due to certain technological barriers, the large scale production of lignocellulosic bioethanol has not been successfully commercialized. In this thesis, membrane filtration as an energy efficient sep

APA, Harvard, Vancouver, ISO, and other styles

31

Sjöberg, John. "Characterization of chemical pulp fiber surfaces with an emphasis on the hemicelluloses." Doctoral thesis, KTH, Fibre and Polymer Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3462.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Coronel, Marie-Dominique. "Tensioactifs et ligninolyse fongique." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376130218.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Zahedifar, Mojtaba. "Novel uses of lignin and hemicellulosic sugars from acid-hydrolysed lignocellulosic materials." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=195786.

Full text

Abstract:

Lignocellulosic materials (LM) are an ever present renewable and available energy source. The energy stored by photosynthesis in the form of vegetation is about ten times more than world's annual energy consumption (Zsuffa, 1982). This source is the only alternative for chemical production after fossil fuels. Formation of organic acids (mainly acetic acid) from hemicellulose during steam treatment of LM leads to acid hydrolysis of cell wall components. Solubilization of hemicellulose and depolymerization of lignin are the most important changes that occur during the process. During hydrolysis

APA, Harvard, Vancouver, ISO, and other styles

34

Abbas, Suzanne. "Étude des propriétés de deux séries de substances d'origine naturelle : les cucurbitacines et les parabènes : analyse de leur biotransformation chez l'homme et mesure du pouvoir cytotoxique des cucurbitacines sur une lignée cellulaire de chondrosarcome humain." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0135/document.

Full text

Abstract:

Les cucurbitacines et les parabènes sont des substances d'origine naturelle appartenant à la famille des triterpéniques cycliques et des esters de l'acide-hydroxybenzoïque, respectivement. Ils sont connus pour posséder chez l'homme plusieurs effets pharmacologiques potentiellement intéressants. Le but de ce travail est d'étudier la biotransformation d'une série de trois cucurbitacines et de cinq parabènes dans le foie humain in vitro, essentiellement par glucuronoconjugaison et hydrolyse et caractériser l'effet cytotoxique des cucurbitacines sur une lignée cellulaire du chondrosarcome humain S

APA, Harvard, Vancouver, ISO, and other styles

35

Uzio, René. "Contribution à l'étude des gousses de vanille : oxydation de la lignine et hydrolyse des composés hétérosides." Aix-Marseille 3, 1987. http://www.theses.fr/1987AIX30078.

Full text

Abstract:

La recherche de techniques permettant de revaloriser les gousses de vanille est rendu necessaire en raison des conditions difficiles du marche de la vanille. Cette revalorisation est basee sur la recherche de procedes permettant d'augmenter la teneur en vanilline des gousses. Pour atteindre cet objectif, deux voies ont ete envisagees. La premiere consiste a la former par oxydation de la lignine contenue dans les gousses epuisees. Trois methodes ont ete retenues et testees. Il s'agit de l'oxydation alcaline au nitrobenzene qui conduit a une augmentation de 0,8 % en vanilline et 1 % en parahydro

APA, Harvard, Vancouver, ISO, and other styles

36

Uzio, René. "Contribution à l'étude des gousses de vanille oxydation de la lignine et hydrolyse des composés hétérosides /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37610455z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Shimizu, Felipe Lange [UNESP]. "Remoção de lignina e hemicelulose: influência na acessibilidade à celulose e sacarificação enzimática." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153394.

Full text

Abstract:

Submitted by Felipe Lange Shimizu null (felipe_lash@hotmail.com) on 2018-04-04T17:40:35Z No. of bitstreams: 1 Versão Final.pdf: 2417638 bytes, checksum: cbd92ea0f55b939141e8dbb758da327f (MD5)<br>Rejected by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br), reason: Prezado Felipe Lange Shimizu, Solicitamos que realize uma nova submissão seguindo as orientações abaixo: - Capa - Faltou a capa no documento enviado. Este item é elemento obrigatório de acordo com as normas de trabalhos do seu Programa de Pós Graduação. Agradecemos a compreensão e aguardamos o envio do novo arquivo.

APA, Harvard, Vancouver, ISO, and other styles

38

Girisuta, Buana. "Levulinic acid from lignocellulosic biomass." [S.l. : Groningen : s.n. ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn/304751316.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Magro, Christian. "Valorisation des pailles de blé par fractionnement thermo-mécano-chimique dans un réacteur bivis." Toulouse, INPT, 1995. http://www.theses.fr/1995INPT057G.

Full text

Abstract:

Le fractionnement des pailles de blé a été réalisé par injection de solutions de soude dans un réacteur bivis clextral du type BC 45. Les produits issus de ce traitement sont des fibres cellulosiques et un filtrat basique contenant une fraction ligneuse et des hémicelluloses. L'étude présentée comprend donc une étude bibliographique concernant les caractéristiques physico-chimiques des pailles de blé et les valorisations actuelles des produits du fractionnement. L'étude du procédé de fractionnement en réacteur bivis a nécessité d'une part la mise au point de l'analytique en ligne et d'autre pa

APA, Harvard, Vancouver, ISO, and other styles

40

Fernandes, Erika Squisato [UNESP]. "Efeito da granulometria no pré-tratamento ácido, acessibilidade, superfície exposta da lignina e sacarificação enzimática do bagaço de cana-de-açúcar." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/156008.

Full text

Abstract:

Submitted by Erika Squisato Fernandes (erikasqui@hotmail.com) on 2018-09-17T20:08:35Z No. of bitstreams: 1 Dissertação-Erika-Final.pdf: 1681682 bytes, checksum: 0d3d284e39457ce899938fd565441dcf (MD5)<br>Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-09-18T12:11:13Z (GMT) No. of bitstreams: 1 fernandes_es_me_rcla.pdf: 1649309 bytes, checksum: 418254e846e33c3699727d682a1a4252 (MD5)<br>Made available in DSpace on 2018-09-18T12:11:13Z (GMT). No. of bitstreams: 1 fernandes_es_me_rcla.pdf: 1649309 bytes, checksum: 418254e846e33c3699727d682a1a4252

APA, Harvard, Vancouver, ISO, and other styles

41

Gonçalves, Dayelle Sâmila Pessotti de Oliveira. "Estudo sobre o modo de ação de enzimas hidrolíticas produzidas por fungos degradadores de madeira sobre substratos com elevado teor de lignina." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-07102013-091359/.

Full text

Abstract:

Os fungos de decomposição parda são eficientes na degradação dos polissacarídeos da madeira, pois, além das enzimas hidrolíticas, podem gerar, via reação de Fenton, radicais hidroxila que são responsáveis pela rápida despolimerização dos polissacarídeos da parede celular sem a remoção prévia da lignina. O presente trabalho analisou se enzimas hidrolíticas do fungo de decomposição parda Gloeophyllum trabeum e as endoglucanases comerciais do ascomiceto Talaromyces emersonii apresentam efeito sinérgico com celulases comerciais durante a hidrólise enzimática de substratos com teor elevado de ligni

APA, Harvard, Vancouver, ISO, and other styles

42

Filho, José Mário Mamede Aguiar. "Análise enzimática de fungos lignocelulolíticos cultivados em vinhaça e bagaço de cana-de-açúcar." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-10032009-095639/.

Full text

Abstract:

O setor sucroalcooleiro é uma importante representação do potencial bioenergético do Brasil. A estimativa da produção de cana-de-açúcar para a safra de 2007/2008, segundo a Companhia Nacional de Abastecimento (Conab), será de mais de 11% que na safra passada. A cana-de-açúcar constitui uma fonte de energia abundante e renovável. Além do aproveitamento de seu caldo para a produção de etanol e do emprego do bagaço para fins energéticos em processos de combustão e gaseificação, seus polissacarídeos constituintes (celulose e polioses) podem ser liberados por hidrólises enzimáticas para serem ferme

APA, Harvard, Vancouver, ISO, and other styles

43

Matoušková, Petra. "Produkce a charakterizace extracelulárních hydroláz z vybraných druhů plísní." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216760.

Full text

Abstract:

This diploma thesis is focused on study of potential production of extracellular hydrolytic enzymes. The theoretical part deals with characterization of selected hydrolytic enzymes, their catalytic properties, the possibility of extracellular hydrolase production by fungi and their applications. In experimental part production strains Aureobasidium pullulans, Fusarium solani and Phanerochaete chrysosporium were used. Productions of cellulase, amylase, xylanase, lipase, protease and lignin-degraded enzymes (laccase, manganese- dependent peroxidase, lignin peroxidase) were observed. Cultivations

APA, Harvard, Vancouver, ISO, and other styles

44

Katrib, Fouad al. "Utilisation du solvant n-méthyl morpholine n-oxyde (MMNO) pour le fractionnement des constituants de la biomasse lignocellulosique et leur saccharification enzymatique : [thèse soutenue sur un ensemble de travaux]." Grenoble 1, 1987. http://www.theses.fr/1987GRE10084.

Full text

Abstract:

La solubilité de la cellulose dans le solvant organique n-methylmorpholine n-oxyde (mmno) a été mise à profit pour concevoir une méthode nouvelle d'extraction des constituants polymériques des parois cellulaires végétales. Dans une première partie l'étude a été consacrée à l'extraction sélective des hémicelluloses de la paille de blé et du bois de peuplier. Il est démontré que bien que la présence de lignine dans les parois représente un obstacle à la solubilisation directe des polysaccharides par mmno, une délignification complète peut être évitée si l'on traite les matériaux lignocellulosiqu

APA, Harvard, Vancouver, ISO, and other styles

45

Leboucher, Jonathan. "Valorisation des anas de lin sous forme de nanocelluloses." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMLH30.

Full text

Abstract:

Ce travail a porté sur la production de nanocristaux de cellulose (NCC) et de nanofibres de cellulose (NFC) à partir d’anas de lin.La production de NCC a été réalisée par hydrolyse acide avec de l’HCl gazeux après blanchiment. L’analyse des résultats de DRX et RMN montrent que la forme des cristallites reste inchangée après l’hydrolyse malgré une faible co-cristallisation le long des faces hydrophiles. La spectroscopie IR en température après un échange isotopique montre que le ratio de matériau marqué évolue avec la température de manière différente selon qu’il s’agit d’anas blanchis ou de NC

APA, Harvard, Vancouver, ISO, and other styles

46

Charcosset, Jean-Yves. "Etude sur le mécanisme d'action de dérivés de l'ellipticine sur des cellules en culture sensibles et résistantes à la 9-hydroxyellipticine." Paris 6, 1986. http://www.theses.fr/1986PA066109.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Pommier, Yves. "Les agents intercalants affectent le fonctionnement des adn topoisomerases deux eukaryotes." Paris 6, 1986. http://www.theses.fr/1986PA066570.

Full text

Abstract:

Parmi les medicaments anticancereux les plus actifs, les agents intercalants de l'adn (anthracyclines, acridines) produisent des lesions sur l'adn de type soit cassure du dna, soit pontage adn-proteine. Ces alterations sont analysees par elution alcaline, sedimentation de nucleotide et sedimentation alcaline. Ces lesions sont reversibles apres suppression des intercalants (culture cellulaire, cellules leuconiques(l1210)). Les dna topoisomerase 2 (enzyme de replication, de transcription, d'organisation de chromatine) sont responsables des lesions provoquees par les agents intercalants du dna, c

APA, Harvard, Vancouver, ISO, and other styles

48

Gate, Laurent. "Influence du degré de méthylation de la daunosamine des anthracyclines dans l'apoptose, l'activité des topoisomérases et la modulation du phénotype de résistance multiple." Rouen, 2000. http://www.theses.fr/2000ROUES005.

Full text

Abstract:

Nous avons étudié sur des cellules érythroleucémiques murines sensibles (FLC) et résistantes (DOX-RFLC) qui surexpriment la P-gp et présentent une diminution de l'expression des topoisomérases II, l'importance de la N-méthylation des anthracyclines dans la modulation de la résistance multidrogue. Ces travaux ont montré que l'augmentation de la N-méthylation de ces agents conduisait à une diminution de l'index de résistance et à une diminution des différences d'incorporation et d'extrusion de ces agents entre cellules DOX-RFLC et FLC. Il fut également observé que les trois molécules inhibaient

APA, Harvard, Vancouver, ISO, and other styles

49

Paris, Cédric. "Développement de nouvelles approches analytiques pour le criblage de peptides chélateurs de fer." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0088.

Full text

Abstract:

Face au besoin croissant de nouvelles molécules bioactives d’origine naturelle, les coproduits de l’industrie alimentaire et de transformation d’agroressources constituent une ressource stratégique à exploiter. En effet, l’hydrolyse enzymatique de protéines végétales ou animales permet de générer une grande variété de séquences peptidiques avec des propriétés biologiques potentielles : antihypertensive, antithrombotique, anticancéreuse, opioïde, antimicrobienne. Malgré le potentiel bioactif de certains peptides, leur présence incertaine et leur faible concentration au sein d’un hydrolysat prot

APA, Harvard, Vancouver, ISO, and other styles

50

Roberts, Virginia Marie [Verfasser]. "Homogeneous and heterogeneous catalyzed hydrolysis of lignin / Virginia Marie Roberts." 2008. http://d-nb.info/990016048/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!