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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Bioconversion of sugarcane bagasse and soybean hulls for the production of a generic microbial feedstock

Chang, Chen-Wei January 2015 (has links)
Lignocellulose, mostly from agricultural and forestry resources, is a potential renewable material for sustainable development of biorefineries. From previous studies, reducing sugar production through biological pretreatment involves two steps: solid-state fermentation (SSF) for delignification, followed by enzymatic hydrolysis by adding celluloytic enzymes (cellulase and xylanase etc.). In the process described in this thesis, the necessary enzymes are produced in-situ and the hydrolysis proceeds directly after the solid-state fermentation. Enzyme hydrolysis releases free amino nitrogen (FAN), reducing sugar and many other potential nutrients from the fermented materials. This method additionally avoids the need for removal of inhibitors compared with conventional chemical pretreatment processes. A range of solid-state fermentations were carried out to investigate the effect of washing procedure, particle size and nitrogen supplement on Trichoderma longibrachiatum growth. From these preliminary studies it was concluded that nitrogen supplementation is a crucial factor to improve significantly the fungi growth and production of feedstock using sugarcane bagasse as raw material. In order to evaluate the influence of environmental humidity on petri dish experiments, moist environments were investigated, with over 75% relative humidity to limit water evaporation from solid-state fermentation. The results showed that moist environments gave approximately 1.85 times the reducing sugar yield than dry environments. The process of simultaneous enzymatic hydrolysis of substrates and fungal autolysis were also studied. The degree of hydrolysis was affected by initial fermented solid to liquid ratio, temperature and pH range. The optimal conditions for subsequent hydrolysis of fermented solids were determined. The optimal solid to liquid ratio, 4% (w/w), temperature 50°C and pH 7 were established. The highest final reducing sugar, 8.9 g/L and FAN, 560 mg/L, were measured after 48 h. The fungal autolysis was identified by image analysis as well as by the consumption of nutrient and the release of free amino nitrogen and phosphorous. Solid state fermentation in a multi-layer tray bioreactor and a packed-bed bioreactor were also developed, with moist air supply for oxygen provision and heat removal. Fermented solids in the multi-layer bioreactor led to the highest subsequent hydrolysis yield on reducing sugar, FAN and Inorganic Phosphorous (IP), 222.85 mg/g, 11.56 mg/g and 19.9 mg/g, respectively. These series of fermentation experiments illustrate the feasibility for the application of consolidated bioprocessing, through simultaneous pretreatment and enzyme production as a more economic and environment-friendly process compared with those reported for chemical pretreatment followed by commercial enzyme process. A growth kinetic model regarding both growth and respiration is also proposed. Ethanol production was studied using the generic feedstock produced from sugarcane bagasse and soybean hulls. Total ethanol yield reached 0.31 mg g-1 (61.4% of theoretical yield) after 30 h of submerged fermentation. The result of subsequent fermentation has already shown the potential of the generic microbial feedstock to be used to produce varied products depending on the microorganism utilised.
122

Estudo da macrófita Typha sp como material adsorvente na remoção das espécies metálicas Cd (II), Cu (II), Cr (III) e Zn (II) em meio aquoso / Study of the Typha sp macrophyte as adsorbent material in the removal of Cd (II), Cu (II), Cr (III) and Zn (II) metal species in aqueous medium

Rabelo, Joseane 31 July 2018 (has links)
Submitted by Joseane Rabelo (josyrabb@gmail.com) on 2018-08-18T17:55:00Z No. of bitstreams: 1 RABELO, J_ME.pdf: 3506789 bytes, checksum: 945c66fa4447e66037b3f637d1c9a0c8 (MD5) / Approved for entry into archive by Ana Carolina Gonçalves Bet null (abet@iq.unesp.br) on 2018-08-20T13:46:21Z (GMT) No. of bitstreams: 1 rabelo_j_me_araiq_int.pdf: 3348948 bytes, checksum: 2b3987dc3b3fc2f4ef2a5f330e2b95c0 (MD5) / Made available in DSpace on 2018-08-20T13:46:21Z (GMT). No. of bitstreams: 1 rabelo_j_me_araiq_int.pdf: 3348948 bytes, checksum: 2b3987dc3b3fc2f4ef2a5f330e2b95c0 (MD5) Previous issue date: 2018-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os biossorventes provenientes de materiais lignocelulósicos são alternativas de baixo custo e mais sustentável para o meio ambiente na remoção das espécies metálicas. Neste caminho, o presente trabalho descreve o uso da macrófita, Typha sp, também conhecida como taboa, para remover as espécies metálicas Cu (II), Cr (III), Cd (II) e Zn (II) em amostras aquosas. Caracterizou-se inicialmente a macrófita Typha sp utilizando as técnicas analíticas como: espectroscopia na região do infravermelho (FT-IR), análise elementar de N e Ressonância magnética nuclear (RMN) de 13C, microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva de raio X (EDS) e análise de área superficial utilizando adsorção de N2. As características adsortivas da Typha sp foram estabelecidas através de experimentos em batelada em função do pH, o tempo de contato e a concentração. As micrografias da Typha sp apresentou-se partículas com morfologia heterogênea, irregular em formato de bastão. O FT-IR e o RMN 13C confirmaram a presença de grupos funcionais como COOH, NH2 e S=C=N, que possuem pares de elétrons não ligantes e que coordenam com as espécies metálicas. A área superficial específica da Typha sp foi menor que 1 m2/g, característico de materiais não porosos. Os experimentos de adsorção mostraram que o pH 5,5 favorece a adsorção das espécies metálicas em estudo. A cinética de adsorção é rápida, sendo menor que 15 min, ajustando aos dados experimentais do modelo cinético de pseudo-segunda ordem. A capacidade máxima de adsorção determinada experimentalmente foi de 9,48, 6,55, 3,01 e 9,52 mg/g para Cr (III), Cu (II), Zn (II) e Cd (II). Respectivamente, os dados obtidos nas isotermas foram aplicados ao modelo Langmuir, cujos valores do coeficiente linear foi maior que 0,95, comprovando o bom ajuste dos dados a este modelo. A adsorção na presença de um segundo íon teve maior interferência para as espécies metálicas de Cu (II) e Zn (II) diminuindo a adsorção em 30 %. Após a determinação das caracteristica adsortivas da Typha sp, essa foi utilizada como suporte sólida na estração em fase sólida. Os parâmetros otimizados no sistema em fluxo para utilizar a Typha sp na extração em fase sólida (SPE) foram: vazão, massa, volume da amostra, concentração do ácido e o volume do eluato, obtendo uma recuperação acima de 78 %. A aplicação nas amostra do Rio Tietê e Paranapanema foram satisfatórias para as espécies Cu (II), Cd (II) e Zn (II), porém a recuperação do Cr (III) foi nula, devido a interferência da matriz. A Typha sp possui grande potencial para ser utilizada como biossorvente na adsorção das espécies metálicas em estudo, devido ao baixo custo do material e a elevada capacidade de adsorção das espécies metálicas. / Biosorbents from lignocellulosic materials are low cost alternatives and more environmentally sustainable in the removal of metal species. In this way, the present work describes the use of the macrophyte, Typha sp, also known as Taboa, to remove the Cu (II), Cr (III), Cd (II) and Zn (II) metal species in aqueous samples. Typha sp macrophyte was initially characterized using analytical techniques such as infrared spectroscopy (FT-IR), elemental analysis of N and 13C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), energy spectroscopy dispersive X-ray diffraction (EDS) and surface area analysis using N2 adsorption. The adsorptive characteristics of Typha sp were established through batch experiments as a function of pH, contact time and concentration. The micrographs of the Typha sp presented particles with heterogeneous morphology, irregular in stick format. FT-IR and 13C NMR confirmed the presence of functional groups such as COOH, NH2 and S = C = N, which have non-binding electron pairs and coordinate with the metallic species. The specific surface area of Typha sp was less than 1 m2/g, characteristic of non-porous materials. The adsorption experiments showed that pH 5.5 favors adsorption of the metal species under study. The kinetics of adsorption is fast, being less than 15 min, adjusting to the experimental data of the kinetic model of pseudo-second order. The maximum adsorption capacity determined experimentally was 9.48, 6.55, 3.01 and 9.52 mg/g for Cr (III), Cu (II), Zn (II) and Cd (II). The data obtained in the isotherms were applied to the Langmuir model, whose linear coefficient values were greater than 0.95, confirming the good fit of the data to this model. The adsorption in the presence of a second ion had greater interference for the Cu (II) and Zn (II) metal species, reducing the adsorption by 30%. After the determination of the adsorptive characteristics of Typha sp, this was used as solid support in the solid phase separation. The optimized parameters in the flow system to use Typha sp in the solid phase extraction (SPE) were: flow, mass, sample volume, acid concentration and eluate volume, obtaining a recovery above 78%. The Cu (II), Cd (II) and Zn (II) species were satisfactory for the Tietê and Paranapanema samples, but the Cr (III) recovery was null due to matrix interference. Typha sp has great potential to be used as a biosorbent in the adsorption of the metal species under study, due to the low cost of the material and the high adsorption capacity of the metallic species. / CAPES
123

Využití procesu extruze při produkci bioplynu ze sena / Using of process the steam explosion at production of biogas from hay

BRAUN, Petr January 2013 (has links)
Pellets from haylage, respectively hay were extruded in an extruder working with a high temperature according to the utility model CZ 21314 with different parameters. The researched parameters of extrusion with a constant time delay were a pressure extrusion and volatile solids. The highest production of methane (CH4) at a fermentation with the temperature 40 °C was monitored from the haylage with a content of the volatile solids 10,6 - 11 % by extrusion with the pressure 1,37 MPa. The highest production of CH4 at a fermentation with the temperature 50 °C was monitored from the haylage with a content of the volatile solids 13,5 - 16,7 % by extrusion with the pressure 1,37 - 1,66 MPa. A kontent of the volatile solids 11,5 % of haylage and extrusion with the pressure 1,35 ? 1,4 were estimated like optimum parameters for a fermentation with the temperature 40 - 50 °C with the highest production of CH4. For evaluation of the effectiveness of investment was used the metod of net present value (NPV). This method is the most commonly used and in most cases the most appropriate.
124

Obtenção de nanocristais de celulose a partir de fibra de bambu usando ultrassom de alta intensidade

Jacinto, Asaph Armando January 2016 (has links)
Orientadora: Prof. Dra. Márcia Aparecida da Silva Spinacé / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2016. / Nos ultimos anos, varios metodos tem sido desenvolvidos para obtencao de nanocristais de celulose. Dentre eles, destaca-se o por ultrassom de alta intensidade, utilizado neste trabalho para fibra de bambu. Foram avaliadas diferentes condicoes de extracao de celulose por ultrassom, alterando tempo de reacao, densidade de massa e de potencia em relacao ao volume e tipo de pre tratamento. As amostras foram caracterizadas por microscopia optica, teor de umidade, espectroscopia de infravermelho, microscopia eletronica de varredura, espalhamento de luz dinamico, microscopia de forca atomica, analise termogravimetrica e difracao de raio X. A fibra de partida apresentou razao de aspecto de 2,33, com comprimento medio de 35 ¿Êm e diametro medio de 15 ¿Êm. Os nanocristais obtidos apresentaram dimensao entre 3 nm a 1 ¿Êm, com geometria elipsoidal. Concluiu-se que maior densidade de potencia e maior quantidade de massa conferiram maior reprodutibilidade ao processo e maior grau de cristalinidade a amostra (75 %), sendo indicado para aplicacao em nanocompositos polimericos . / In the last years, a lot of methods have been developed to obtain cellulose nanocrystals. Among them, there is high intensity ultrasound, used in this work to bamboo fiber. Different conditions of extraction of cellulose by ultrasound were evaluated, changing reaction time, mass and power density in relation to volume and pretreatment type. The samples were characterized by optics microscopy, moisture content, infrared spectroscopy, scanning electronic microscopy, dynamic light scattering, atomic force microscopy, thermogravimetric analysis and X ray diffraction. The original fiber showed aspect ratio of 2,33, with medium length of 35 ìm and medium diameter of 15 ìm. The nanocrystals showed dimensions between 3 nm and 1 ìm, with ellipsoidal geometry. It was observed that higher power density and higher mass allow better reproducibility of the process and higher crystallinity to the sample (75 %), it is indicated to applications in polymeric nanocomposites.
125

Fermentação de xaropes artificiais constituídos de glicose e xilose e de hidrolisados enzimáticos de bagaço de cana-de-açúcar utilizando leveduras não convencionais e cocultivos

Rech, Fernanda Roberta 23 September 2016 (has links)
Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-04-25T13:43:14Z No. of bitstreams: 1 Tese Fernanda Roberta Rech.pdf: 330878 bytes, checksum: dcfd7515c7bf4521f3c575214f90f867 (MD5) / Made available in DSpace on 2017-04-25T13:43:14Z (GMT). No. of bitstreams: 1 Tese Fernanda Roberta Rech.pdf: 330878 bytes, checksum: dcfd7515c7bf4521f3c575214f90f867 (MD5) Previous issue date: 2017-04-24
126

Pré-tratamento de biomassa lignocelulósica por macrofungos regionais para posterior produção de etanol de segunda geração

Hartmann, Caroline 25 August 2017 (has links)
Com a crescente busca por fontes energéticas renováveis alternativas aos combustíveis fósseis, o uso de biomassa lignocelulósica, como bagaço de cana-de-açúcar e serragem de eucalipto, surge como uma alternativa para a produção de etanol de segunda geração. Porém, são necessários pré-tratamentos para facilitar a ação das enzimas sobre a biomassa. Entre os métodos de pré-tratamentos, o biológico tem sido estudado, por não demandar o uso de químicos e altos custos energéticos, apresentar condições brandas de processo e não levar à formação de compostos inibidores às etapas posteriores. No presente trabalho, bagaço de cana-de-açúcar e serragem de eucalipto foram pré-tratados por diferentes espécies de basidiomicetos. As amostras pré-tratadas foram hidrolisadas com complexo enzimático de Peninillium echinulatum e posteriormente realizou-se a fermentação dos açúcares liberados. Com relação à produção de enzimas lignolíticas, as espécies que se destacaram em bagaço de cana-de-açúcar foram Marasmiellus palmivorus VE111, Pleurotus pulmonarius PS2001, Pleurotus albidus 88F-13, Pycnoporus sanguineus PR32 e Trametes villosa 82I6. Em serragem de eucalipto, os teores destas enzimas foram significativamente inferiores aos obtidos com as mesmas espécies em bagaço de cana-de-açúcar. Em análise de espectros de FTIR, T. villosa 82I6 e P. pulmonarius PS2001 apresentaram proporções favoráveis entre o consumo de celulose, hemicelulose e lignina em ambas as biomassas testadas. Em ensaios de hidrólise enzimática, pré-tratamento biológico por T. villosa 82I6 aumentou a digestibilidade da celulose presente na serragem de 3,7% para 42% e do bagaço de cana-de-açúcar de 12,9% para 22%. T. villosa 82I6 destacou-se, visto que, em ambas as biomassas, foi o basidiomiceto que promoveu o maior liberação de glicose na etapa de hidrólise em amostras pré-tratadas por menores tempos. Em fermentação alcoólica dos hidrolisados de ambas as biomassas pré-tratadas por T. villosa 82I6, o rendimento em etanol a partir de bagaço de cana-de-açúcar foi aumentado para 20,2±0,5 mg/g após 49 dias de tratamento, enquanto que o controle apresentava rendimento de 10,1±0,8 mg/g. O rendimento em etanol a partir de serragem de eucalipto foi aumentado para 25,5±0,7, 18,2±0,03 e 25,5±3,8 mg/g, após respectivamente 7, 28 e 42 dias de tratamento, enquanto que o controle apresentava rendimento de 6,5±0,2 mg/g. Foi demonstrado o potencial do T. villosa 82I6 como agente biológico em pré-tratamentos de biomassas lignocelulósicas e o impacto do pré-tratamento sobre as etapas subsequentes. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-11-30T19:22:32Z No. of bitstreams: 1 Dissertacao Caroline Hartmann.pdf: 2412511 bytes, checksum: a07736115b288116c6298b801c3ef764 (MD5) / Made available in DSpace on 2017-11-30T19:22:32Z (GMT). No. of bitstreams: 1 Dissertacao Caroline Hartmann.pdf: 2412511 bytes, checksum: a07736115b288116c6298b801c3ef764 (MD5) Previous issue date: 2017-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / With the growing demand for renewable energy sources as alternatives to fossil fuels, the use of lignocellulosic biomass, such as sugarcane bagasse and eucalyptus sawdust, is an alternative for the production of second generation ethanol. However, pretreatments are needed to facilitate the action of enzymes on biomass. Among the pretreatment methods, the biological has been studied, since it does not require the use of chemicals and high energy costs, to present soft conditions of process and not formation of inhibitory compounds to the later stages. In the present study, sugarcane bagasse and eucalyptus sawdust were pretreated by different basidiomycete species. The pretreated samples were hydrolyzed with enzymatic complex of Peninillium echinulatum and later the fermentation of the liberated sugars was carried out. In relation to the production of lignolytic enzymes, the species that stood out in sugarcane bagasse were Marasmiellus palmivorus VE111, Pleurotus pulmonarius PS2001, Pleurotus albidus 88F-13, Pycnoporus sanguineus PR32 and Trametes villosa 82I6. In eucalyptus sawdust, these enzymes were significantly lower than those obtained by the same species in sugarcane bagasse. In the analysis of FTIR spectra, T. villosa 82I6 and P. pulmonarius PS2001 presented favorable proportions between cellulose, hemicellulose and lignin consumption in both biomasses tested. In enzymatic hydrolysis assays, biological pretreatment with T. villosa 82I6 increased the digestibility of the pulp present in the sawdust to 42% and of the sugarcane bagasse to 22%. T. villosa 82I6 was highlighted, since in both biomass, it was the basidiomycete that promoted the highest glucose release in the hydrolysis step, in samples pretreated for shorter times. In alcoholic fermentation of the hydrolysates of both biomasses pretreated with T. villosa 82I6, ethanol yield from sugarcane bagasse was increased to 20.2±0.5 mg/g after 49 days of treatment, while the control presented yield of 10.1±0.8 mg/g. The ethanol yield from eucalyptus sawdust was increased to 25.5±0.7, 18.2±0.03 and 25.5±3.8 mg/g, respectively after 7, 28 and 42 days of treatment, while the control presented yield of 6.5±0.2 mg/g. The potential of T. villosa 82I6 as a biological agent in pretreatments of lignocellulosic biomass and the impact of pretreatment on subsequent steps has been demonstrated.
127

Potencial biotecnológico do metagenoma de rúmen bovino da raça nelore (Bos tauros indicus), visando à desconstrução da biomassa vegetal / Biotechnological potential of a rumen metagenome from nelore bovine (Bos tauros indicus) viewing the descontruction of plant biomass

Pavani, Claudio Damasceno [UNESP] 22 June 2017 (has links)
Submitted by CLAUDIO DAMASCENO PAVANI null (claudio_dp913@hotmail.com) on 2017-07-10T13:24:55Z No. of bitstreams: 1 Tese Claudio_Damasceno _Pavani.docx: 10100219 bytes, checksum: b0579cc0881c7d4a4bd458b37a7be301 (MD5) / Rejected by Monique Sasaki (sayumi_sasaki@hotmail.com), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A versão final da dissertação/tese deve ser submetida no formato PDF (Portable Document Format). O arquivo PDF não deve estar protegido e a dissertação/tese deve estar em um único arquivo, inclusive os apêndices e anexos, se houver. Por favor, corrija o formato do arquivo e realize uma nova submissão. Agradecemos a compreensão. on 2017-07-13T19:46:29Z (GMT) / Submitted by CLAUDIO DAMASCENO PAVANI null (claudio_dp913@hotmail.com) on 2017-07-17T13:16:54Z No. of bitstreams: 1 Tese Claudio_Damasceno _Pavani.pdf: 4981240 bytes, checksum: c45fa10351f84e64eb25cd201dcc69c9 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-07-18T16:17:22Z (GMT) No. of bitstreams: 1 pavani_cd_dr_jabo.pdf: 4981240 bytes, checksum: c45fa10351f84e64eb25cd201dcc69c9 (MD5) / Made available in DSpace on 2017-07-18T16:17:22Z (GMT). No. of bitstreams: 1 pavani_cd_dr_jabo.pdf: 4981240 bytes, checksum: c45fa10351f84e64eb25cd201dcc69c9 (MD5) Previous issue date: 2017-06-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A comunidade mundial busca pela obtenção de biocombustível celulósico, embora ainda seja um grande desafio a desconstrução do arranjo lignocelulósico para obtenção de açúcares livres de forma eficiente e economicamente viável. A fim de superar tais desafios, avanços conquistados pela metagenômica ressaltam sua aplicação como alternativa para compreender e desvendar o grande potencial metabólico presente nos ambientes, buscando encontrar em tais ambientes novas enzimas que atuem de forma eficiente na desconstrução do material lignocelulósico. Neste trabalho utilizou-se, a abordagem metagenômica para caracterização de genes com potencial para degradar biomassa vegetal e também para avaliação da diversidade taxonômica do ambiente ruminal bovino (Cow_1), bem como comparar os dados coletados com outros metagenomas disponíveis. Amostras de conteúdo ruminal de três bovinos machos da raça Nelore foram coletadas para a obtenção da amostra de DNA metagenômico, que posteriormente foi sequenciada pelo sequenciador HiScan SQ (Illumina). Foram obtidas aproximadamente 63 milhões de sequências (Cow _1), 2 x 100 pb. Dentre os 26 filos encontrados o filo Bacteroidetes foi o mais abundante, seguido de Firmicutes e Proteobacteria. Para a anotação gênica foi utilizado os bancos de dados Pfam, GO, KEGG e CAZy. Foram associadas ORFs relacionadas a 86 famílias de Glycoside Hydrolases (GHs), 52 famílias de Carbohydrate-Binding Modules (CBMs), 4 famílias de Auxiliary Activities (AAs), 16 famílias de Carbohydrate Esterases (CEs), 55 famílias de Glycosyl Transferases (GTs), 16 famílias de Polysaccharide Lyases (PLs), 1 família de S-layer homology (SLH) domain e 1 família de cohesina e dockerina, estes genes estão relacionados a formação do complexo enzimático para desconstrução da biomassa vegetal (celulossoma). O metagenoma da cow_1 analisado apresentou maior quantidade de genes relacionados à desconstrução da biomassa vegetal, quando comparados com outros 11 metagenomas. Além disso, os metagenomas dos ambientes lignocelulósicos apresentaram, principalmente, maior abundância de GH3, GH5, GH8, GH10 e GH11, genes que são importantes na degradação da lignocelulose quando comparados com o grupo de metagenomas não lignocelulósico. Os ambientes lignocelulósicos também revelaram maior abundância de sequências de domínios que se ligam na estrutura da celulose (CBM1, CBM10, CBM11, CBM16, CBM3, CBM63, CBM79 e CBM56), domínios que se ligam na estrutura da hemicelulose (CBM35, CBM61, CBM62 e CBM67) e domínios que atuam na estrutura da celulose e xilana (CBM37, CBM44 e CBM59). O metagenoma ruminal mostrou uma grande diversidade de enzimas responsáveis pela degradação da biomassa vegetal, demonstrando seu potencial como fonte de enzimas com potencial biotecnológico. Os metagenomas lignocelulósicos mostraram uma maior abundância de GH3, GH5, GH8, GH10 e GH11, genes que são importantes na degradação de celulose, celobiose, manana, xilana e xilo-oligossacarídeos quando comparados ao grupo não-lignocelulósico. / The world community search to obtain cellulosic biofuel; however the deconstruction of the lignocellulosic arrangement to obtain free sugars in an efficient and economically viable way is still a great challenge. Advances achieved through the metagenomic emphasize its application as an alternative to unfold the great metabolic potential present in the environments in order to overcome such challenges. Thus, a metagenomic approach was used to characterize genes with potential to degrade plant biomass and to evaluate the taxonomic diversity of the Nelore bovine ruminal environment. Samples were collected from three bovine males to obtain the DNA sample, which were sequentially sequenced by the HiScan SQ (Illumina) sequencer. About 63 million sequences, 2 x 100 bp, were obtained. Among the 26 phyla found, Bacteroidetes was the most abundant, followed by Firmicutes and Proteobacteria. For gene annotation was used the Pfam, GO, KEGG and CAZy databases. A total of 86 families of Glycoside Hydrolases (GHs), 52 families of Carbohydrate Binding Modules (CBMs), 4 families of Auxiliary Activities (AAs), 16 Esterase Carbohydrate (CEs), 55 GlycosylTransferases (GTs) Polysaccharide Lyases (PLs), 1 S-homology homology (SLH) domain and 1 family of cohesin and dockerine was associated. these genes are related to the formation of the enzymatic complex for deconstruction of plant biomass (cellulosome). The cow_1 metagenome presented a greater number of genes related to deconstruction of plant biomass when compared to other 11 metagenomes. In addition, the metagenomes of the lignocellulosic environments presented, mainly, greater abundance of GH3, GH5, GH8, GH10 and GH11, genes that are important in the degradation of lignocellulose when compared with the group of non-lignocellulosic metagenomes. Focusing on the CBMs, the metagenomes of the lignocellulosic group showed a greater abundance of CBM1, CBM10, CBM11, CBM16, CBM3, CBM63, CBM79 and CBM56 that bind in the cellulose structure; CBM35, CBM61, CBM62 and CBM67 which bind to the hemicellulose structure; CBM37, CBM44 and CBM59 that act on the structure of cellulose and xylan. The ruminal metagenome showed a great diversity of enzymes responsible for the degradation of the plant biomass, demonstrating its potential as a source of enzymes with biotechnological potential. Lignocellulosic metagenomes showed a greater abundance of GH3, GH5, GH8, GH10 and GH11, genes that are important in the degradation of cellulose, cellobiose, mannan, xylan and xylo-oligosaccharides when compared to the non-lignocellulosic group.
128

Engineering Cellular Transport Systems to Enhance Lignocellulose Bioconversion

January 2018 (has links)
abstract: Lignocellulosic biomass represents a renewable domestic feedstock that can support large-scale biochemical production processes for fuels and specialty chemicals. However, cost-effective conversion of lignocellulosic sugars into valuable chemicals by microorganisms still remains a challenge. Biomass recalcitrance to saccharification, microbial substrate utilization, bioproduct titer toxicity, and toxic chemicals associated with chemical pretreatments are at the center of the bottlenecks limiting further commercialization of lignocellulose conversion. Genetic and metabolic engineering has allowed researchers to manipulate microorganisms to overcome some of these challenges, but new innovative approaches are needed to make the process more commercially viable. Transport proteins represent an underexplored target in genetic engineering that can potentially help to control the input of lignocellulosic substrate and output of products/toxins in microbial biocatalysts. In this work, I characterize and explore the use of transport systems to increase substrate utilization, conserve energy, increase tolerance, and enhance biocatalyst performance. / Dissertation/Thesis / Doctoral Dissertation Biological Design 2018
129

Fermentação de xaropes artificiais constituídos de glicose e xilose e de hidrolisados enzimáticos de bagaço de cana-de-açúcar utilizando leveduras não convencionais e cocultivos

Rech, Fernanda Roberta 23 September 2016 (has links)
No description available.
130

Pré-tratamento de biomassa lignocelulósica por macrofungos regionais para posterior produção de etanol de segunda geração

Hartmann, Caroline 25 August 2017 (has links)
Com a crescente busca por fontes energéticas renováveis alternativas aos combustíveis fósseis, o uso de biomassa lignocelulósica, como bagaço de cana-de-açúcar e serragem de eucalipto, surge como uma alternativa para a produção de etanol de segunda geração. Porém, são necessários pré-tratamentos para facilitar a ação das enzimas sobre a biomassa. Entre os métodos de pré-tratamentos, o biológico tem sido estudado, por não demandar o uso de químicos e altos custos energéticos, apresentar condições brandas de processo e não levar à formação de compostos inibidores às etapas posteriores. No presente trabalho, bagaço de cana-de-açúcar e serragem de eucalipto foram pré-tratados por diferentes espécies de basidiomicetos. As amostras pré-tratadas foram hidrolisadas com complexo enzimático de Peninillium echinulatum e posteriormente realizou-se a fermentação dos açúcares liberados. Com relação à produção de enzimas lignolíticas, as espécies que se destacaram em bagaço de cana-de-açúcar foram Marasmiellus palmivorus VE111, Pleurotus pulmonarius PS2001, Pleurotus albidus 88F-13, Pycnoporus sanguineus PR32 e Trametes villosa 82I6. Em serragem de eucalipto, os teores destas enzimas foram significativamente inferiores aos obtidos com as mesmas espécies em bagaço de cana-de-açúcar. Em análise de espectros de FTIR, T. villosa 82I6 e P. pulmonarius PS2001 apresentaram proporções favoráveis entre o consumo de celulose, hemicelulose e lignina em ambas as biomassas testadas. Em ensaios de hidrólise enzimática, pré-tratamento biológico por T. villosa 82I6 aumentou a digestibilidade da celulose presente na serragem de 3,7% para 42% e do bagaço de cana-de-açúcar de 12,9% para 22%. T. villosa 82I6 destacou-se, visto que, em ambas as biomassas, foi o basidiomiceto que promoveu o maior liberação de glicose na etapa de hidrólise em amostras pré-tratadas por menores tempos. Em fermentação alcoólica dos hidrolisados de ambas as biomassas pré-tratadas por T. villosa 82I6, o rendimento em etanol a partir de bagaço de cana-de-açúcar foi aumentado para 20,2±0,5 mg/g após 49 dias de tratamento, enquanto que o controle apresentava rendimento de 10,1±0,8 mg/g. O rendimento em etanol a partir de serragem de eucalipto foi aumentado para 25,5±0,7, 18,2±0,03 e 25,5±3,8 mg/g, após respectivamente 7, 28 e 42 dias de tratamento, enquanto que o controle apresentava rendimento de 6,5±0,2 mg/g. Foi demonstrado o potencial do T. villosa 82I6 como agente biológico em pré-tratamentos de biomassas lignocelulósicas e o impacto do pré-tratamento sobre as etapas subsequentes. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / With the growing demand for renewable energy sources as alternatives to fossil fuels, the use of lignocellulosic biomass, such as sugarcane bagasse and eucalyptus sawdust, is an alternative for the production of second generation ethanol. However, pretreatments are needed to facilitate the action of enzymes on biomass. Among the pretreatment methods, the biological has been studied, since it does not require the use of chemicals and high energy costs, to present soft conditions of process and not formation of inhibitory compounds to the later stages. In the present study, sugarcane bagasse and eucalyptus sawdust were pretreated by different basidiomycete species. The pretreated samples were hydrolyzed with enzymatic complex of Peninillium echinulatum and later the fermentation of the liberated sugars was carried out. In relation to the production of lignolytic enzymes, the species that stood out in sugarcane bagasse were Marasmiellus palmivorus VE111, Pleurotus pulmonarius PS2001, Pleurotus albidus 88F-13, Pycnoporus sanguineus PR32 and Trametes villosa 82I6. In eucalyptus sawdust, these enzymes were significantly lower than those obtained by the same species in sugarcane bagasse. In the analysis of FTIR spectra, T. villosa 82I6 and P. pulmonarius PS2001 presented favorable proportions between cellulose, hemicellulose and lignin consumption in both biomasses tested. In enzymatic hydrolysis assays, biological pretreatment with T. villosa 82I6 increased the digestibility of the pulp present in the sawdust to 42% and of the sugarcane bagasse to 22%. T. villosa 82I6 was highlighted, since in both biomass, it was the basidiomycete that promoted the highest glucose release in the hydrolysis step, in samples pretreated for shorter times. In alcoholic fermentation of the hydrolysates of both biomasses pretreated with T. villosa 82I6, ethanol yield from sugarcane bagasse was increased to 20.2±0.5 mg/g after 49 days of treatment, while the control presented yield of 10.1±0.8 mg/g. The ethanol yield from eucalyptus sawdust was increased to 25.5±0.7, 18.2±0.03 and 25.5±3.8 mg/g, respectively after 7, 28 and 42 days of treatment, while the control presented yield of 6.5±0.2 mg/g. The potential of T. villosa 82I6 as a biological agent in pretreatments of lignocellulosic biomass and the impact of pretreatment on subsequent steps has been demonstrated.

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