Spelling suggestions: "subject:"Pr?tratamento"" "subject:"Pr?otratamento""
1 |
Avalia??o da influ?ncia de surfactantes qu?mico e biol?gico na hidr?lise enzim?tica de casca de coco verde ap?s pr?-tratamento ?cido/alcalino e com per?xido de hidrog?nio alcalinoAra?jo, Cynthia K?rzia Costa de 18 March 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T20:34:44Z
No. of bitstreams: 1
CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-18T22:50:18Z (GMT) No. of bitstreams: 1
CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5) / Made available in DSpace on 2016-08-18T22:50:18Z (GMT). No. of bitstreams: 1
CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5)
Previous issue date: 2016-03-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / ?No Brasil s?o gerados diversos tipos de subprodutos e res?duos agroindustriais como: baga?o de ped?nculo de caju, baga?o de cana-de-a??car, baga?o de coco e outros. A disposi??o final desses res?duos, ou seja, sua elimina??o causa s?rios problemas ambientais. Apesar de uma parte ser utilizada para fins diversos, uma grande quantidade ainda permanece sem utiliza??o. Neste sentido, os res?duos de conte?do lignocelul?sico, como a casca do coco verde, constituem uma mat?ria-prima renov?vel e abundante cujo aproveitamento ? desej?vel e tem provocado um interesse crescente para o uso na cadeia de produ??o de etanol de 2? gera??o. Neste trabalho foi utilizada como mat?ria-prima a casca de coco verde, a qual foi submetida a dois pr?-tratamentos com o objetivo de melhorar a acessibilidade das enzimas ? celulose. Os pr?-tratamentos aplicados ao baga?o de coco foram: ?cido/Alcalino utilizando H2SO4 0,6M e, em seguida, NaOH 1M e, o pr?-tratamento com Per?xido de Hidrog?nio Alcalino (PHA) a uma concentra??o de 7,35% (v/v) e pH 11,5. O objetivo principal do estudo em quest?o, foi avaliar a influ?ncia do biossurfactante (ramnolip?deo produzido pela Pseudomonas aeruginosa), durante a hidr?lise da casca de coco verde. Para efeito de compara??o, foram realizadas hidr?lises utilizando surfactante qu?mico, nesse caso o Triton X-100, e hidr?lises sem adi??o de surfactantes. Dessa forma, observou-se que, com a aplica??o de ambos os pr?-tratamentos, foi poss?vel atingir uma maior convers?o de celulose ao comparar com o material in natura. No entanto, ao analisar os resultados obtidos para o processo de hidr?lise com a aplica??o de surfactantes, verificou-se que o ramnolip?deo produzido melhora, consideravelmente, a convers?o celul?sica da casca de coco verde, atingindo uma convers?o de 33% ap?s 72 horas de hidr?lise, enquanto que, a convers?o m?xima atingida com o uso do Triton X-100 foi de 23%. Esses resultados mostram que o biossurfactante pode ser aplicado na hidr?lise enzim?tica de materiais lignocelul?sicos, de modo a apresentar uma boa influ?ncia no processo.? / In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip?d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.
|
2 |
Avalia??o do potencial da torta de buriti (Mauritia flexuosa L.) para obten??o de bioetanol de segunda gera??oGomes, Pedro Henrique de Oliveira 19 August 2016 (has links)
Disponibiliza??o do conte?do parcial, conforme Termo de Autoriza??o. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-02-06T17:43:23Z
No. of bitstreams: 2
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
pedro_henrique_oliveira_gomes_parcial.pdf: 166812 bytes, checksum: c52b21dee0bd71b327c054bdb20ce24a (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-02-07T13:25:40Z (GMT) No. of bitstreams: 2
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
pedro_henrique_oliveira_gomes_parcial.pdf: 166812 bytes, checksum: c52b21dee0bd71b327c054bdb20ce24a (MD5) / Made available in DSpace on 2017-02-07T13:25:40Z (GMT). No. of bitstreams: 2
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
pedro_henrique_oliveira_gomes_parcial.pdf: 166812 bytes, checksum: c52b21dee0bd71b327c054bdb20ce24a (MD5)
Previous issue date: 2016 / O bioetanol pode ser produzido a partir de materiais lignocelul?sicos, que s?o constitu?dos de
carboidratos complexos na forma de celulose, hemicelulose e amido, ampliando as
possibilidades de fontes de energias alternativas. Uma dessas s?o os res?duos agr?colas, como
as tortas, coprodutos de processos de extra??o mec?nica de ?leos de frutos, sementes e cereais
(oleaginosas), que representam um desafio por muitas vezes n?o possu?rem um destino vi?vel
ou at? rent?vel que atenda as exig?ncias ambientais. Um desses ? o buriti (Mauritia flexuosa
L.), fonte de um ?leo com alto teor de caroten?ides representando, assim, aplica??es em
ind?strias aliment?cias, cosm?ticas e farmacol?gicas e resultando em ac?mulo de seu material.
O trabalho foi desenvolvido a partir da torta de buriti obtida ap?s extra??o mec?nica de seu
?leo. Foi verificado que a torta ? constitu?da por aproximadamente 44% de sua massa por
carboidratos livres ou polimerizados. Foram realizados tratamentos qu?micos com solu??es de
?cido dilu?do e base em duas etapas distintas, a fim de promover a remo??o da hemicelulose e
lignina. Por fim, foi feita a hidr?lise com complexo enzim?tico de celulases, enzimas que
hidrolisam cadeias celul?sicas em monossacar?deos de glicose, substrato utilizado por
microrganismos como a levedura Saccharomyces cerevisiae no metabolismo celular, tendo
como produto excretado o etanol. Ap?s a hidr?lise enzim?tica, obteve teores de 53,58%
(m/m) de glicose liberada do farelo tratado, apresentando um rendimento em torno de 60%
(m/m). Com a fermenta??o do hidrolisado, obtido ap?s o tratamento enzim?tico, foi verificada
a obten??o de etanol em rendimento (fator de convers?o de substrato em produto, Yp/s) de
0,43 em rela??o ? quantidade de substrato utiliza??o na hidr?lise enzim?tica. O produto obtido
foi analisado em cromat?grafo a g?s acoplado ao espectr?metro de massa, confirmando a
obten??o de bioetanol. Al?m disso, foram realizadas medidas de microscopia eletr?nica por
varredura e difratometria de raios-X, verificando altera??es na estrutura f?sica e morfol?gica
do material ao longo do processo. Por fim, ratificou-se a possibilidade de aplicar a torta de
buriti na obten??o de etanol de segunda gera??o. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Bioethanol can be produced from lignocellulosic materials, that are made up of carbohydrate
complexes in the form of cellulose, hemicellulose and starch, expanding the possibilities of
alternative energy sources. One of these are agriculture residues, such as pies, co-products of
mechanical extraction processes of fruit oils, seeds and cereals (oil), which represent a
challenge in many times do not possess a viable or even profitable destination that meets the
environmental requirements. One of these is the buriti (Mauritia flexuosa L.), source of a oil
with high content of carotenes, representing thus, applications in food industries, cosmetic
and pharmaceutical, resulting in accumulation of its material. The work was developed from
the buriti pie obtained after mechanical extraction of its oil. It was verified that the pie is
comprise by approximately 44% of its mass by free carbohydrates or polymerized. Chemical
treatments were performed with dilute acid solutions and base in two distinct steps in order to
promote the removal of hemicellulose and lignin. Finally, the hydrolysis was done with the
enzyme complex of cellulases, enzymes that hydrolyze cellulose chains in monosaccharide
glucose, a substrate used by microorganisms such as Saccharomyces cerevisiae yeast in cell
metabolism, with ethanol as the product excreted . After enzymatic hydrolysis, it was
obtained content of 53.58% (m/m) of glucose released from the treated bran, showing a yield
around 60% (m/m). With the fermentation of the hydrolyzate obtained after the enzymatic
treatment was verified obtaining of ethanol in yield (substrate conversion factor in product,
Yp / s) of 0.43 compared to the amount of substrate used in the enzymatic hydrolysis. The
obtained product was analyzed in a gas chromatograph coupled to a mass spectrometer,
confirming obtaining bioethanol. In addition, were carried out measures of scanning electron
microscopy and X-ray diffraction, checking changes in physical and morphological structure
of the material throughout the process. Finally, ratifies the possibility of applying the buriti
pie in getting second-generation ethanol.
|
3 |
Otimiza??o do pr?-tratamento ?cido de torta de caro?o de algod?o e baga?o de malte com farinha de pupunha para produ??o de bioetanol de segunda gera??o / Optimization of acid pretreatment of cottonseed cake and crushed malt with peach palm flour for the production of second generation bioethanolSilva, Alexandre Alves da January 2012 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:44Z
No. of bitstreams: 5
ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:24:21Z (GMT) No. of bitstreams: 5
ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:24:21Z (GMT). No. of bitstreams: 5
ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5)
Previous issue date: 2013-02-21 / Na atualidade, n?o se pode desconsiderar a necessidade de desenvolvimento de tecnologias que suportem as demandas por energias renov?veis. Uma das vias para a produ??o de energia renov?vel ? a transforma??o de biomassas vegetais em combust?veis l?quidos. Os res?duos agroindustriais s?o candidatos potenciais como insumos para essa nova ind?stria de energia. Dessa forma a presente disserta??o teve por objetivo avaliar o potencial da torta de caro?o de algod?o e do baga?o de malte com farinha de pupunha como mat?rias-primas para a produ??o de etanol de segunda gera??o e otimizar etapa de pr?-tratamento ?cido do material lignocelul?sico necess?ria para a utiliza??o da celulose. Inicialmente foi determinada a composi??o centesimal da torta de caro?o de algod?o e do baga?o de malte em rela??o aos valores percentuais de umidade, cinzas, extrato et?reo, prote?na bruta, a??cares sol?veis totais, amido, hemicelulose, celulose, lignina, fibra em detergente neutro e fibra em detergente ?cido. Com os resultados da caracteriza??o qu?mica p?de-se estimar uma produ??o potencial superior a 300 L de etanol/tonelada de cada res?duo. Para a otimiza??o do pr?-tratamento ?cido para remo??o da fra??o hemicelul?sica foi aplicada metodologia de Planejamento Fatorial atrav?s de Delineamento Composto Central Rotacional. O programa STATISTICA Vers?o 8.0 (Statsoft Inc., Tulsa,) foi utilizado para an?lise dos dados. A qualidade do ajuste da equa??o do modelo foi expressa pelo coeficiente de determina??o (R?) e sua signific?ncia estat?stica condicionada pelo teste-F. O material insol?vel recuperado ap?s o pr?-tratamento otimizado teve as fra??es hemicelul?sicas e de amido completamente removidas. O hidrolisado obtido em condi??es otimizadas de pr?-tratamento apresentou 15,7% de a??cares redutores para o baga?o de malte e pupunha e 5,9% de a??cares redutores para a torta de caro?o de algod?o. O tratamento dos hidrolisados com carv?o ativado removeu n?o menos que 58% dos compostos fen?licos a? presentes. Os testes de fermentabilidade com Saccharomyces cerevisiae e Pichia stipitis foram promissores. A fermenta??o com S. cerevisiae apresentou um YP/S de 0,30 para a torta de caro?o de algod?o e 0,37 para o baga?o de malte. Os rendimentos fementativos com P. stipitis variaram de 9% a 25% para os res?duos agroindustriais. Os dados experimentais indicam que a torta de caro?o de algod?o (Gossypium hirsutum L.) e baga?o malte com farinha de pupunha tem elevado potencial para a produ??o de bioetanol. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT
Nowadays, one cannot ignore the need for developing technologies that support the demands for renewable energy. One of the pathways for production of renewable energy is the transformation of vegetal biomass to liquid fuels. The agro-industrial residues as raw materials are potential candidates for this new energy industry. Thus the aim of the present dissertation was to evaluate the potential of cottonseed cake and crushed malt with peach palm flour as raw materials for the production of second generation ethanol and optimize step of acid pretreatment of lignocellulosic material. Initially was determined the chemical composition of cotton seed cake and crushed malt in relation to the percentages of moisture, ash, ether extract, crude protein, total soluble sugars, starch, hemicellulose, cellulose, lignin, neutral detergent fiber and acid detergent fiber. With the results of chemical characterization it was possible to estimate a potential yield of more than 300L of ethanol / ton of each residue. For the optimization of acid pretreatment for hemicelluloses removal was applied a Central Composite Design. The software STATISTICA Version 8.0 (Statsoft Inc., Tulsa,) was used for data analysis. The goodness of fit of the model equation was expressed by the coefficient of determination (R?) and its statistical significance conditioned by F-test. The insoluble material recovered after the optimized pretreatment had starch and hemicellulose fractions completely removed. The hydrolyzate obtained under optimized conditions of pretreatment showed 15.7% of reducing sugars to the crushed malt and 5.9% of reducing sugars for cottonseed cake. The treatment of the hydrolysates with activated charcoal removed no less than 58% of the phenolic compounds present there. Fermentability tests with Saccharomyces cerevisiae and Pichia stipitis have been promising. Fermentation with S. cerevisiae showed a YP/S of 0.30 for cottonseed cake and 0.37 for the crushed malt. Fermentative yields with P. stipitis ranged from 9% to 25% for agro-industrial residues. The experimental data indicate that the cottonseed cake (Gossypium hirsutum L.) and crushed malt has a high potential for the production of bioethanol.
|
4 |
Coordena??o entre as respostas da catalase e da ascorbato peroxidade em folhas de feij?o caupi submetidas a diferentes fontes de per?xido de hidrog?nioSilva, Ivanice Bezerra da 19 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:03:40Z (GMT). No. of bitstreams: 1
IvaniceBS_DISSERT_.pdf: 1465096 bytes, checksum: 4d6e3186d410a1d86bc5ff69ec8190c4 (MD5)
Previous issue date: 2012-12-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The plants are often exposed to variations in environmental conditions that may
trigger metabolic disturbances leading to a consequent loss in productivity of crops.
These stressful conditions usually induce an accumulation of reactive oxygen
species (ROS) in the cell, a condition known how oxidative stress. Among these
species, hydrogen peroxide (H2O2) is an important molecule involved in numerous
signaling mechanisms. The present study aimed to understand the relationship
between the different enzymatic mechanisms of elimination of H2O2 by catalase
(CAT) and ascorbate peroxidase (APX) in leaf tissues of seedlings of the species
Vigna unguiculata L. Walp, under conditions of oxidative stress induced by
application of CAT inhibitor, 3-amino-1,2,4-triazole (3-AT), and H2O2 itself on the
roots. Three experiments were conducted. The first experiment was performed
applying the compound 3-AT (5 mM) during the time (hours). In the second
experiment, seedlings were exposed to different concentrations of H2O2 (2.5, 5.0,
7.5, 10 mM) for 48 h. The third strategy included the pre-treatment with H2O2 (2.5
mM) for 24 h, followed by subsequent treatment with the inhibitor 3-AT and recovery
control condition. Treatment with 3-AT causes a strong inhibition of CAT activity in
leaf tissues accompanied by an increase of activity of APX. However a decrease in
oxidative damage to lipids is not observed as indicated by TBARS. It was observed
that activity of APX is directly linked to the content of peroxide. Inductions in the
activities of CAT and APX were observed mainly in the seedlings treated with 2.5 mM
H2O2. This can be associated with a decrease in oxidative damage to lipids. In
contrast, one same tendency was not observed in treatments with higher
concentrations of this ROS. These results suggest that the concentration of 2.5 mM
H2O2 can induce responses antioxidants later in seedling cowpea. This concentration
when applied as pre-treatment for 24 h promoted an induction systems removers
CAT and APX, both in activity and in terms of gene expression. However this
increment was not observed in the recovered plants and the plants subsequently
subjected to 3-AT. Additionally, the pretreatment was not sufficient to attenuate the
inhibition of CAT activity and oxidative damage to lipids caused by the subsequent
application of this inhibitor. The results showed that the application of 3-AT and H2O2
in the root systems of seedlings of cowpea promote changes in the parameters
analyzed in leaf tissues that indicate a direct response to the presence of these
factors or systemic signaling mecanisms. H2O2 appears to activate the responses of
two antioxidant systems in this study thar does not promote greater protection in
case of additional treatment with 3-AT. This demonstrates the importance of the CAT
system. In this work, complete results indicate that there is a difference between the
signaling and the effects caused by exposure to H2O2 and by treatment with 3-AT / As plantas s?o expostas frequentemente a varia??es nas condi??es ambientais, que
podem desencadear dist?rbios metab?licos levando a uma consequente perda na
produtividade das culturas. Estas condi??es estressoras normalmente induzem um
ac?mulo de esp?cies reativas de oxig?nio (EROS) na c?lula, caracterizando uma
condi??o de estresse oxidativo. Dentre estas esp?cies, est? o per?xido de
hidrog?nio (H2O2), uma importante mol?cula envolvida em in?meros mecanismos de
sinaliza??o. O presente estudo pr?pos compreender a rela??o entre os diferentes
mecanismos enzim?ticos de elimina??o do H2O2 pelas enzimas catalase (CAT) e
ascorbato peroxidase (APX) em tecidos foliares de pl?ntulas da esp?cie Vigna
unguiculata L. Walp, sob condi??es de estresse oxidativo induzido por meio da
aplica??o do inibidor de CAT, o 3-amino-1,2,4-triazol (3-AT), e do pr?prio H2O2 no
sistema radicular. Tr?s experimentos foram realizados. No primeiro experimento foi
realizada a aplica??o do composto 3-AT (5 mM) durante o tempo (horas). No
segundo experimento, pl?ntulas foram expostas a diferentes concentra??es de H2O2
(2,5; 5,0; 7,5; 10 mM) por 48 h. A terceira estrat?gia compreendeu o pr?-tratamento
com H2O2 (2,5 mM) por 24 h, seguido de tratamentos subsequentes com o inibidor
3-AT e a recupera??o a condi??o controle. O tratamento com o 3-AT ocasiona uma
forte inibi??o na atividade da CAT nos tecidos foliares, acompanhado por uma
tend?ncia de aumento na atividade da APX. Este, no entanto, n?o levou a uma
diminui??o dos danos oxidativos aos lip?deos, como indicado pelo TBARS.
Observou-se que a atividade da APX est? diretamente ligada aos conte?dos de
per?xido. Indu??es nas atividades da CAT e da APX foram observadas,
principalmente nas pl?ntulas tratadas com 2,5 mM de H2O2, o que est? associado a
uma diminui??o dos danos oxidativos aos lip?deos. Em contraste, esta mesma
tend?ncia n?o foi evidenciada nos tratamentos com maiores concentra??es desta
ROS. Estes resultados sugerem que a concentra??o de 2,5 mM de H2O2 pode
induzir respostas antioxidantes posteriores nas pl?ntulas de feij?o caupi. De fato,
esta concentra??o, quando aplicada na forma de pr?-tratamento durante 24 h,
promoveu uma indu??o dos sistemas removedores da CAT e da APX, tanto na
atividade, como ao n?vel de express?o g?nica. No entanto, esta melhora n?o foi
observada nas plantas recuperadas e nas plantas posteriormente submetidas ao 3-
AT. Adicionalmente, o pr?-tratamento n?o foi suficiente para atenuar a inibi??o da
atividade de CAT e os danos oxidativos aos lip?deos provocados pela subsequente
aplica??o deste inibidor. Os resultados obtidos demonstraram que a aplica??o do
composto 3-AT e do H2O2 nos sistemas radiculares de pl?ntulas de feij?o caupi
promovem modifica??es nos par?metros analisados nos tecidos foliares, o que pode
indicar tanto uma resposta direta ? presen?a destes fatores, quanto uma resposta de
sinaliza??o sist?mica nestas plantas. O H2O2 parece ativar as respostas dos 2
sistemas antioxidantes testados, no entanto, n?o promove uma maior prote??o em
caso de tratamento adicional com o 3-AT, demonstrando a import?ncia do sistema
da CAT. Analisados em conjunto, os resultados deste estudo indicam que h? uma
diferen?a entre a sinaliza??o e os efeitos provocados pela exposi??o ao H2O2 e por
tratamento com 3-AT
|
5 |
Aproveitamento sustent?vel do baga?o de cana de a??car para obten??o do acetato de celuloseSilva, Valdic Luiz da 15 August 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-14T18:51:54Z
No. of bitstreams: 1
ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-15T19:22:11Z (GMT) No. of bitstreams: 1
ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5) / Made available in DSpace on 2016-01-15T19:22:11Z (GMT). No. of bitstreams: 1
ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5)
Previous issue date: 2014-08-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O aproveitamento sustent?vel de res?duos decorrente da agroind?stria ? atualmente
foco de pesquisas, com destaque para o baga?o de cana de a??car (BCA), por ser o
res?duo lignocelul?sico produzido em maior volume na agroind?stria brasileira, onde
a biomassa residual tem sido aplicada na produ??o de energia el?trica e
bioprodutos. Neste trabalho, foi produzida celulose com elevada pureza, a partir do
(BCA), por polpa??o soda/antraquinona e, posterior convers?o em acetato de
celulose. A celulose comercial Avicel foi utilizada para compara??o. A obten??o do
acetato de celulose ocorreu por rea??o de acetila??o homog?nea, modificando-se as
vari?veis, tempo reacional, em horas, (8, 12, 16, 20 e 24) e temperatura, em ?C, (25
e 50). Os espectros de FTIR indicaram bandas caracter?sticas id?nticas para os
materiais celul?sicos, o que demonstra a efici?ncia da separa??o por polpa??o. A
caracteriza??o da celulose e do acetato obtidos ocorreu por espectroscopia de
infravermelho (FTIR), difra??o de raios X (DRX), an?lises termogravim?tricas
(TG/DTG/DSC), microscopia eletr?nica de varredura (MEV) e determina??o do grau
de substitui??o (GS) para o acetato de celulose, para confirma??o da acetila??o. Os
tempos reacionais ?timos para a obten??o de diacetatos e triacetatos, em ambas as
temperaturas foram 20 h e 24 h. O acetato de celulose, produzido do BCA,
apresentou GS entre 2,57 e 2,7 na temperatura de 25?C e, a 50 ?C, os GS obtidos
foram 2,66 e 2,84, indicando real convers?o da celulose do BCA em di e triacetatos.
De modo comparativo, a celulose comercial Avicel apresentou GS de 2,78 e 2,76 a
25 ?C e 2,77 e 2,75 a 50 ?C. Os dados foram obtidos no tempo de 20 h e 24 h,
respectivamente. O melhor resultado ocorreu para a s?ntese do acetato de celulose
obtida do BCA, com GS de 2,84 a 50?C e 24 h, sendo classificado como triacetato
de celulose, que apresentou resultado superior ao acetato produzido com a celulose
comercial Avicel, demonstrando a potencialidade de convers?o da celulose obtida a
partir de um res?duo lignocelul?sicos (BCA), de baixo custo, com perspectivas de
utiliza??o comercial do acetato de celulose / The sustainable use of waste resulting from the agribusiness is currently the focus of
research, especially the sugar cane bagasse (BCA), being the lignocellulosic waste
produced in greater volume in the Brazilian agribusiness, where the residual biomass
has been applied in production energy and bioproducts. In this paper, pulp was
produced in high purity from the (BCA) by pulping soda / anthraquinone and
subsequent conversion to cellulose acetate. Commercial cellulose Avicel was used
for comparison. The obtained cellulose acetate was homogeneous acetylation
reaction by modifying the variables, the reaction time in hours (8, 12, 16, 20 and 24)
and temperature in ? C (25 and 50). FTIR spectra showed characteristic bands
identical to cellulosic materials, demonstrating the efficiency of separation by pulping.
The characterization of cellulose acetate was obtained and by infrared spectroscopy
(FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG / DTG / DSC),
scanning electron microscopy (SEM) and determining the degree of substitution (DS
) for the cellulose acetate to confirm the acetylation. The optimal reaction time for
obtaining diacetates and triacetates, at both temperatures were 20 and 24 h.
Cellulose acetate produced BCA presented GS between 2.57 and 2.7 at 25 ? C and
50 ? C GS obtained were 2.66 and 2.84, indicating the actual conversion of cellulose
BCA of di- and triacetates. Comparative mode, commercial cellulose Avicel GS
showed 2.78 and 2.76 at 25 ? C and 2.77 to 2.75 at 50 ? C. Data were collected in
time of 20 h and 24 h, respectively. The best result was for the synthesis of cellulose
acetate obtained from the BCA GS 2.84 to 50 ? C and 24 hours, being classified as
cellulose triacetate, which showed superior result to that produced with the
commercial ethyl cellulose Avicel, demonstrating converting potential of cellulose
derived from a lignocellulosic residue (BCA), low cost, prospects of commercial use
of cellulose acetate
|
6 |
Produ??o de bioetanol a partir de ped?nculo de caju (Anacardium occidentale L.) por fermenta??o submersa / Produ??o de bioetanol a partir de ped?nculo de caju (Anacardium occidentale L.) por fermenta??o submersa / Bioethanol production from cashew apple (Anacardium occidentale L.) by submerged fermentation / Bioethanol production from cashew apple (Anacardium occidentale L.) by submerged fermentationRocha, Maria Valderez Ponte 22 November 2010 (has links)
Made available in DSpace on 2014-12-17T15:01:51Z (GMT). No. of bitstreams: 1
MariaVPR_TESE_1-170.pdf: 4608142 bytes, checksum: 9ed83cbe76a127f48714302cd74c674a (MD5)
Previous issue date: 2010-11-22 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Recently, global demand for ethanol fuel has expanded very rapidly, and this should further
increase in the near future, almost all ethanol fuel is produced by fermentation of sucrose or
glucose in Brazil and produced by corn in the USA, but these raw materials will not be
enough to satisfy international demand. The aim of this work was studied the ethanol
production from cashew apple juice. A commercial strain of Saccharomyces cerevisiae was
used for the production of ethanol by fermentation of cashew apple juice. Growth kinetics and
ethanol productivity were calculated for batch fermentation with different initial sugar
(glucose + fructose) concentration (from 24.4 to 103.1 g.L-1). Maximal ethanol, cell and
glycerol concentrations (44.4 g.L-1, 17.17 g.L-1, 6.4 g.L-1, respectively) were obtained when
103.1 g.L-1 of initial sugar concentration were used, respectively. Ethanol yield (YP/S) was
calculated as 0.49 g (g glucose + fructose)-1. Pretreatment of cashew apple bagasse (CAB)
with dilute sulfuric acid was investigated and evaluated some factors such as sulfuric acid
concentration, solid concentration and time of pretreatment at 121?C. The maximum glucose
yield (162.9 mg/gCAB) was obtained by the hydrolysis with H2SO4 0.6 mol.L-1 at 121?C for 15
min. Hydrolysate, containing 16 ? 2.0 g.L-1 of glucose, was used as fermentation medium for
ethanol production by S. cerevisiae and obtained a ethanol concentration of 10.0 g.L-1 after 4
with a yield and productivity of 0.48 g (g glucose)-1 and 1.43 g.L-1.h-1, respectively. The
enzymatic hydrolysis of cashew apple bagasse treated with diluted acid (CAB-H) and alkali
(CAB-OH) was studied and to evaluate its fermentation to ethanol using S. cerevisiae.
Glucose conversion of 82 ? 2 mg per g CAB-H and 730 ? 20 mg per g CAB-OH was
obtained when was used 2% (w/v) of solid and loading enzymatic of 30 FPU/g bagasse at 45
?C. Ethanol concentration and productivity was achieved of 20.0 ? 0.2 g.L-1 and 3.33 g.L-1.h-1,
respectively when using CAB-OH hydrolyzate (initial glucose concentration of 52.4 g.L-1).
For CAB-H hydrolyzate (initial glucose concentration of 17.4 g.L-1), ethanol concentration
and productivity was 8.2 ? 0.1 g.L-1 and 2.7 g.L-1.h-1, respectively. Hydrolyzates fermentation
resulted in an ethanol yield of 0.38 g/g glucose and 0.47 g/g glucose, with pretreated CABOH
and CAB-H, respectively. The potential of cashew apple bagasse as a source of sugars for
ethanol production by Kluyveromyces marxianus CE025 was evaluated too in this work. First,
the yeast CE025 was preliminary cultivated in a synthetic medium containing glucose and
xylose. Results showed that it was able to produce ethanol and xylitol at pH 4.5. Next, cashew
apple bagasse hydrolysate (CABH) was prepared by a diluted sulfuric acid pre-treatment. The
fermentation of CABH was conducted at pH 4.5 in a batch-reactor, and only ethanol was
produced by K. marxianus CE025. The influence of the temperature in the kinetic parameters
was evaluated and best results of ethanol production (12.36 ? 0.06 g.L-1) was achieved at 30
?C, which is also the optimum temperature for the formation of biomass and the ethanol with
a volumetric production rate of 0.25 ? 0.01 g.L-1.h-1 and an ethanol yield of 0.42 ? 0.01 g/g
glucose. The results of this study point out the potential of the cashew apple bagasse
hydrolysate as a new source of sugars to produce ethanol by S. cerevisiae and K. marxianus
CE025. With these results, conclude that the use of cashew apple juice and cashew apple
bagasse as substrate for ethanol production will bring economic benefits to the process,
because it is a low cost substrate and also solve a disposal problem, adding value to the chain
and cashew nut production / Recentemente, a demanda mundial por etanol combust?vel tem se expandido de
forma muito r?pida, sendo quase todo etanol combust?vel ? produzido por fermenta??o de
sacarose no Brasil ou glicose de milho nos Estados Unidos, por?m, estas mat?rias-primas n?o
ser?o suficientes para satisfazer a demanda internacional. Neste contexto, o objetivo deste
trabalho foi avaliar a produ??o de bioetanol a partir do ped?nculo de caju. Para tal fim,
inicialmente, estudou-se a produ??o de etanol utilizando o suco de caju como fonte de
carbono, avaliando a influ?ncia da concentra??o inicial de substrato por Saccharomyces
cerevisiae. Nessa etapa, os melhores resultados foram utilizando uma concentra??o inicial de
a??car de 87,71 g.L-1 obtendo a concentra??o m?xima de etanol de 42,8 ? 3 g.L-1 com uma
produtividade de 9,71 g.L-1.h-1 e rendimento de etanol de 0,49 g etanol/g glicose + frutose.
Posteriormente, estudou-se a produ??o de etanol utilizando como material lignocelul?sico o
baga?o de caju (CAB) que continha 20,9% celulose, 16,3% hemicelulose e 33,6% lignina +
cinzas. Inicialmente estudou-se o pr?-tratamento do CAB com ?cido sulf?rico dilu?do
avaliando-se diferentes par?metros, obtendo as maiores concentra??es dos a??cares glicose
(22,8 ? 1,5 g.L-1) e xilarabin (arabinose + xilose plus, 29,2 ? 2,4 g.L-1), na fra??o l?quida
(CAB-H), no pr?-tratamento conduzido em autoclave a 121?C por 15 min usando H2SO4 0,6
mol.L-1 e 30% m/v de CAB, com rendimentos de glicose, xilarabin e a??cares totais de 75,99
? 5,0, 97,17 ? 8,1 e 173,16 ? 13,0 mg.(g de baga?o)-1, respectivamente. A convers?o obtida
nesse pr?-tratamento com base na percentagem de celulose e hemicelulose do CAB foi 322,1
? 20,1 mg glicose.(g celulose)-1 e 514,1 ? 43,1 mg xilarabin.(g hemicelulose)-1. Na
fermenta??o do hidrolisado CAB-H por S. cerevisiae obteve-se 10 g.L-1 de etanol ap?s 4
horas de cultivo, com rendimento de 0,48 g.(g glicose)-1 e produtividade de 2,62 g.L-1h-1.
Ap?s, estudou-se a hidr?lise enzim?tica do CAB ap?s pr?-tratamento com H2SO4 dilu?do
(CAB-H) e alcalino (CAB-OH) e a fermenta??o dos hidrolisados por S. cerevisiae para
produzir etanol. Uma convers?o de glicose de 82 ? 2 mg.(gCAB-H)-1 e 730 ? 20 mg.(gCAB-OH)-1
foi obtida utilizando 2% (m/v) de s?lidos e carga enzim?tica de 30 FPU.(g baga?o)-1 a 45?C.
Na fermenta??o conduzida com o hidrolisado obtido da hidr?lise enzim?tica do CAB-OH,
obteve-se uma concentra??o de etanol, produtividade e rendimento de 20,0 ? 0,2 g.L-1, 3,33
g.L-1.h-1 e 0,38 g.(g de glicose)-1, respectivamente. Para o hidrolisado da hidr?lise do CAB-H,
a concentra??o de etanol foi 8,2 ? 0,1 g.L-1 com 2,7 g.L-1.h-1 de produtividade e rendimento
de 0,47 g.(g glicose)-1 em 3 h de ensaio. O potencial do baga?o de caju como fonte de
a??cares para a produ??o de etanol por Kluyveromyces marxianus CE025 tamb?m foi
avaliado e verificou-se a influ?ncia da temperatura nos par?metros cin?ticos, sendo os ensaios
conduzidos em batelada a pH 4,5, utilizado o hidrolisado (CAB-H) como fonte de carbono.
Os melhores resultados para a produ??o de etanol foram a 30?C, coincidindo com a
temperatura ?tima de crescimento, resultando em 12,36 ? 0,06 g.L-1 de etanol, com uma taxa
volum?trica de produ??o de 0,26 ? 0,01 g.L-1.h-1 e rendimento de 0,42 ? 0,01 g.(g de glicose)-
1. Os resultados apresentados demonstram o potencial do ped?nculo de caju (suco e baga?o)
como nova fonte de carbono para produzir etanol por S. cerevisiae e K. marxianus CE025
|
Page generated in 0.0802 seconds