Orientadores: Aline Carvalho da Costa, José Geraldo da Cruz Pradella / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-24T06:05:42Z (GMT). No. of bitstreams: 1 Machado_DanieleLongo_M.pdf: 2642371 bytes, checksum: 08fe9958b60f1f20bc5bb385ae8820e4 (MD5) Previous issue date: 2013 / Resumo: A hidrólise enzimática de materiais lignocelulósicos compreende uma etapa de adsorção das enzimas celulases a esse material, e as chamadas isotermas de adsorção são curvas extremamente úteis nesse estudo, pois indicam a forma como o soluto (adsorbato) adsorverá no adsorvente; dão uma estimativa da quantidade máxima de soluto que o adsorvente adsorverá, entre outras características importantes. São empregadas também para a obtenção de condições mais favoráveis e eficientes na conversão da biomassa a açúcares fermentescíveis. Assim, para melhor entendimento de como o processo da adsorção enzimática interfere nos rendimentos da hidrólise enzimática da celulose, este trabalho abordou estudos específicos, tais como, a determinação da cinética e dos parâmetros das isotermas de adsorção das enzimas do complexo celulolítico sobre diferentes biomassas. Trabalhou-se com o bagaço de cana-de-açúcar pré-tratado hidrotérmico (BH) que apresentou 31,97% de lignina em sua composição e organossolve (BO), com 4,42% de lignina, e também com Avicel e com um isolado de lignina (IL). Os experimentos de cinética e isoterma de adsorção foram realizados em duplicata com volume reacional de 15 mL contendo tãmpão citrato de sódio 50 mM pH 4.8 complementado com with 0.02% de azida sódica por grrama de substrato onde a biomassa foi adicionada. Nos ensaios de cinética, os fracos foram incubados em um shaker (Marconi AM-832) a 50ºC e 4ºC, onde a agitação variou de 40 a 250 rpm. Foram recolhidas amostras dos frascos em tempos pré-determinados e centrifugadas por 15 min a 4,000 rpm para remoção dos materiais insolúveis. O teor de proteína do sobrenadante foi determinado usando o método de Bradford. As isotermas de adsorção da celulase para as biomassas foram conduzidas pela variação da quantidade proteica da enzima celulase (0,1 ¿ 4,5 mg/mL). Os dados experimentais foram estimados pela isoterma de adsorção de Langmuir usando o software OriginPro8.0. Os parâmetros Emax e Kp obtidos pelo ajuste dos dados experimentais mostraram-se diferentes para os diferentes materiais. Uma maior capacidade de adsorção (36,93 mg celulase/g de substrato) e, consequentemente, uma afinidade maior da enzima celulase pelo bagaço pré-tratado foi observada para o pré-tratamento hidrotérmico, pois a celulase, além de adsorver na celulose, também adsorve na lignina, em menor extensão. Os dados obtidos da isoterma de adsorção da celulase sobre o IL confirmam a adsorção improdutiva da enzima na lignina (Emax= 11,92 mg/g) e mostram como esses estudos da adsorção das enzimas em IL são importantes, porque se torna possível distinguir a adsorção a porções da celulose e frações da lignina. A agitação exerceu influência significativa no fenômeno de adsorção, onde o aumento da agitação até 150 rpm melhorou a mistura entre as enzimas e o substratos, porém, a partir de 200 rpm não foram observadas mudanças significativas nos perfis de enzima adsorvida. Palavras-chaves: Lignocelulose, cinética de adsorção, isoterma de Langmuir, hidrólise enzimática / Abstract: The enzymatic hydrolysis of lignocellulosic biomass involves one step of adsorption of cellulase enzymes on this material, and the adsorption isotherms are curves extremely useful for this research, because they show how the solute (adsorbate) will adsorb on the adsorbent; give an estimate of what is highest quantity of solute adsorbed by the adsorbent, among other information. They are also used to attain more favorable and efficient conditions in the conversion of biomass into fermentable sugars. Therefore, for a better understanding of how the enzymatic adsorption process interferes in the enzymatic hydrolysis of cellulose yields, this study has proposed specific studies, such as the determination of the kinetics and parameters of adsorption isotherms of enzymes from cellulolityc complex on different biomasses. Sugarcane bagasse hydrothermal pretreated (BH), which presented 31.97% (w/w) of lignin in its composition, and the organosolv (BO), with 4.42% (w/w) of lignin, were evaluated, as well as Avicel and an isolated lignin (IL). The adsorption kinetics and isotherm experiments assays were performed in duplicate with reaction volume of 15 mL of sodium citrate buffer 50 mM pH 4.8 supplemented with 0.02% sodium azide per gram of substrate to which biomass was added. The adsorption kinetics assays the flasks were incubated in shaker (Marconi AM-832) at 50ºC and 4ºC where the stirring ranged from 40 to 250 rpm. Flasks were withdrawn at different time intervals and centrifuged repeatedly for 15 min in a centrifuge at 4,000 rpm to remove insoluble materials. The protein content of the supernatant was determined using Bradford method (Bradford, 1976). Cellulase adsorption isotherm on biomasses was conducted by varying the amount of cellulase protein (0.1¿4.5 mg/mL). The experimental data were fit to the Langmuir adsorption isotherm using the software OriginPro 8.0. The parameters Emax and Kp estimated by experimental data adjustment showed different values to the different materials. The highest adsorption capacity (36.93 mg of cellulase/ g of substrate) and, consequently, the highest affinity of the cellulase enzyme for the pretreated bagasse was found for the hydrothermal pretreated bagasse, as cellulase, besides adsorbing on cellulose, also adsorbs on lignin to a lesser extent. The cellulase adsorption on IL data confirms the unproductive adsorption of the enzyme on lignin (Emax = 11.92 mg/g) and shows how these adsorption studies of enzymes in IL are relevant, because it becomes feasible to distinguish the adsorption on portions of cellulose and on lignin fractions. Stirring had significant influence on the adsorption phenomenon, with the increase in stirring up to 150 rpm improving the mixture of enzymes and substrate; however, over 200 rpm stirring influence was not significant. Key-words: Lignocellulose, adsorption kinetics, Langmuir isotherm, enzymatic hydrolysis / Mestrado / Desenvolvimento de Processos Químicos / Mestra em Engenharia Química

Orientador: Rubens Maciel Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T04:26:50Z (GMT). No. of bitstreams: 1 Dias_MarinaOliveiradeSouza_D.pdf: 10320958 bytes, checksum: 60f6577e8a240362deee06c3fda94214 (MD5) Previous issue date: 2011 / Resumo: O aumento na demanda por biocombustíveis motivou a produção de bioetanol a partir de materiais lignocelulósicos (etanol de 2ª geração). Bioetanol é produzido em larga escala no Brasil a partir da cana-de-açúcar (etanol de 1ª geração) há mais de trinta anos. Grandes quantidades de materiais lignocelulósicos (bagaço e palha) são geradas durante o processamento da cana-de-açúcar; o bagaço é queimado para produção de energia, e a palha é queimada para facilitar a colheita ou deixada no campo. Buscou-se neste estudo determinar as melhores condições para inserção da produção de etanol de 2ª geração no Brasil a partir das frações lignocelulósicas da cana-de-açúcar, que possibilita o aumento da produção de etanol usando a mesma área cultivada e permite o uso de parte da infraestrutura do processo convencional. Neste sentido, são estudadas tecnologias que maximizam a produção de etanol, incluindo aquelas que diminuem o consumo de energia do processo convencional. Além disso, diferentes tecnologias para produção de etanol de segunda geração foram comparadas, incluindo diferentes tipos de pré-tratamento e condições de hidrólise enzimática. Simulações computacionais foram desenvolvidas para comparar as tecnologias; os resultados mostram que: a otimização do consumo de energia do processo convencional de produção de etanol e o uso de parte da palha são essenciais para aumentar significativamente a produção de etanol a partir da cana-de-açúcar; o teor de sólidos utilizado nas reações de hidrólise apresenta um grande impacto na produção de etanol total; ganhos podem ser obtidos ao se integrar a produção de etanol de 2ª geração e eletricidade em uma destilaria autônoma convencional / Abstract: Increase on biofuels demand has motivated the production of bioethanol from lignocellulosic materials (2nd generation ethanol). Bioethanol has been produced in large scale in Brazil from sugarcane (1st generation ethanol) for more than 30 years. Large amounts of lignocellulosic materials (bagasse and trash) are generated during sugarcane processing; bagasse is burnt for production of energy, while trash is burnt in the field to improve the harvest or left in the field. The best conditions for insertion of 2nd generation ethanol production in Brazil using sugarcane lignocellulosic fractions as feedstock were investigated in this study, leading to an increase on ethanol production using the same cultivated area and part of the infrastructure already available at the conventional process. In this way, technologies for maximization of ethanol production from sugarcane, including those that decrease energy consumption of the conventional ethanol production process were evaluated. In addition, different technologies for production of 2nd generation ethanol were compared, including different pretreatment methods and conditions for enzymatic hydrolysis. Simulations were developed to compare these technologies; results show that optimization of the energy demand of the conventional ethanol production process and use of part of the trash in the industry are crucial in order to increase ethanol production from sugarcane; solids content of hydrolysis reactions presents an important impact on overall ethanol production; signi_cant gains can be obtained when 2nd generation ethanol and electricity production are integrated in an autonomous distillery / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Abstract Water-related problems are increasing globally, and new, low-cost technologies are needed to resolve them. Lignocellulosic waste materials contain reactive functional groups that can be used to provide a bio-based platform for the production of water treatment chemicals. Research on bio-based ion exchange materials in the treatment of real wastewaters is needed. In this thesis, anion exchange materials were prepared through chemical modification (epichlorohydrin, ethylenediamine and triethylamine) using five Finnish lignocellulosic materials as bio-based platforms. Scots pine sawdust and bark (Pinus sylvestris), Norway spruce bark (Picea abies), birch bark (Betula pendula/pubescens) and peat were chosen due to their local availability and abundance. The focus was placed on NO3- removal, but uptake of heavy metals, such as nickel, was also observed and studied. Studies on maximum sorption capacity, mechanism, kinetics, and the effects of temperature, pH and co-existing anions were used to elucidate the sorption behaviour of the prepared materials in batch and column tests. All five materials removed over 70% of NO3- at pH 3–10 (initial conc. 30 mg N/l). Quaternized pine sawdust worked best (max. capacity 32.8 mg NO3-N/g), and also in a wide temperature range (5–70°C). Column studies on quaternized pine sawdust using mining wastewater and industrial wastewater from a chemical plant provided information about the regeneration of exhausted material and its suitability for industrial applications. Uptake of Ni, V, Co and U was observed. Column studies proved the easy regeneration and reusability of the material. For comparison, pine sawdust was also modified using N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride and utilized to remove NO3- from groundwater and industrial wastewater. A maximum sorption capacity of 15.3 mg NO3-N/g was achieved for the synthetic solution. Overall, this thesis provides valuable information about bio-based anion exchange materials and their use in real waters and industrial applications. / Tiivistelmä Edullisia ja kestäviä vedenkäsittelytekniikoita tarvitaan kasvavien vesiongelmien ratkaisemiseen. Lignoselluloosaa, kuten sahanpurua, syntyy suuria määriä teollisuuden sivutuotteena. Sen reaktiivisia funktionaalisia ryhmiä voidaan modifioida kemiallisesti ja valmistaa siten biopohjaisia vedenkäsittelykemikaaleja. Tutkimustietoa oikeiden jätevesien puhdistuksesta biopohjaisilla ioninvaihtomateriaaleilla tarvitaan lisää, jotta materiaalien käyttöä voidaan kehittää ja edistää. Tässä väitöstyössä valmistettiin anioninvaihtomateriaaleja modifioimalla kemiallisesti viittä suomalaista lignoselluloosamateriaalia: männyn sahanpurua ja kuorta (Pinus sylvestris), kuusen kuorta (Picea abies), koivun kuorta (Betula pendula/pubescens) ja turvetta. Menetelmässä käytettiin epikloorihydriiniä, etyleenidiamiinia ja trietyyliamiinia orgaanisessa liuotinfaasissa. Työssä keskityttiin erityisesti nitraatin poistoon sekä synteettisistä että oikeista jätevesistä. Materiaalien soveltuvuutta teollisiin sovelluksiin arvioitiin maksimisorptiokapasiteetin, sorptioisotermien, kinetiikka- ja kolonnikokeiden sekä pH:n, lämpötilan ja muiden anionien vaikutusta tutkivien kokeiden avulla. Kaikki viisi kationisoitua tuotetta poistivat yli 70 % nitraatista laajalla pH-alueella (3–10). Kationisoitu männyn sahanpuru osoittautui parhaaksi materiaaliksi (32,8 mg NO3-N/g), ja se toimi laajalla lämpötila-alueella (5–70°C). Kolonnikokeet osoittivat sen olevan helposti regeneroitavissa ja uudelleenkäytettävissä. Tuotetta testattiin myös kaivos- ja kemiantehtaan jäteveden käsittelyyn, ja kokeissa havaittiin hyviä nikkeli-, uraani-, vanadiini- ja kobolttireduktioita. Männyn sahanpurua modifioitiin vertailun vuoksi myös kationisella monomeerilla, N-(3-kloro-2-hydroksipropyyli)trimetyyliammoniumkloridilla. Tuotteen maksimisorptiokapasiteetiksi saatiin 15,3 mg NO3-N/g ja se poisti nitraattia saastuneesta pohjavedestä. Kokonaisuudessaan väitöskirjatyö tarjoaa uutta tietoa biopohjaisten ioninvaihtomateriaalien valmistamisesta ja niiden soveltuvuudesta oikeiden teollisuusjätevesien käsittelyyn.

Biogas production from energy crops grown on arable land often competes with food and feed production. Wetland plants offer an alternative source of biomass as well as offering a number of environmental benefits such as nutrient removal from wastewaters, carbon sequestration and reducing the use of mineral fertilizer. The aim of this study is to investigate the effect of harvest time on biogas production of Phragmites australis and Glyceria maxima and to perform a cost-benefit analysis of using these wetland plants as a substrate for biogas production. The results of the batch experiment show that the overall biogas production and specific methane yields of biomass harvested in June was higher than biomass harvested in September due the increased lignocellulosic nature of the more mature September plant. The cost-benefit showed that in Sweden it is not currently profitable to solely use wetland plants for biogas production. For both species the highest costs were seen in the June harvested biomass, this was due to the much higher fresh weight and increased transportation costs. For both species the highest revenues generated were the June harvested biomass, this was due to the higher specific methane yields. It was found that the harvest time that was closest to profitability from both species was the June harvest for Phragmites australis. Although the costs were higher for harvesting in June, this was outweighed by the higher amount of electricity produced for this scenario. If transportation distance was to be increased it could result in September being the favourable harvest time. Therefore, individual circumstances of the farmers could decide which is the optimal harvest time. Although solely using wetland plants for biogas production is not currently profitable, co-digestion and pre-treatment are options to investigate that could change this. Also if a greater financial value is put on the socioeconomic benefits such as increased biodiversity, aesthetic value and global warming mitigation it may be financially viable in the future.

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Vast- quantities of lignocellulosic materials, representing potential substrates for the cultivation of speciality mushrooms, are produced annually in South Africa. A number of these materials are derived as waste products of the timber and agricultural industries, e.g. Maranti (Shorea spp.) and Port Jackson Willow (Acacia longifolia) respectively. The screening of various wood-degrading fungi, which are cultivated worldwide for their production of speciality mushrooms, indicated that under the environmental conditions considered, certain species were adapted to cultivation on these lignocellulosic wastes (Pleurotus species) whereas others were not (Lentinus edodes and Flammulina velutipes). Furthermore, intra- and interspecies specific differences in the growth and production potential of the various lignocellulolytic fungi investigated on synthetic and natural medium were discovered. Biochemical and genetical investigations of these strains indicated differences between and within species which were often significant. Species varied qualitatively and quantitatively in the lignocellulolytic enzymes produced, which was loosely correlated with productivity on the different media investigated. Genetical studies, using RAPD fingerprinting, indicated that the Pleurotus genus is highly variable which supports the observed differences in growth, yield and enzymatic activity between different strains and species.

The launch of national and international initiatives to reduce pollution, reliance on fossil fuels and increase the beneficiation of agricultural wastes has prompted research into sugar monomer production from lignocellulosic wastes. These sugars can subsequently be used in the production of biofuels and environmentally degradable plastics. This study investigated the use of synergistic combinations of commercial and pure enzymes to lower enzyme costs and loadings, while increasing enzyme activity in the hydrolysis of agricultural waste. Pineapple pomace was selected due to its current underutilisation and the substantial quantities of it produced annually, as a by-product of pineapple canning. One of the primary costs in beneficiating agricultural wastes, such as pineapple pomace, is the high cost of enzyme solutions used to generate reducing sugars. This can be lowered through the use of synergistic combinations of enzymes. Studies related to the inclusion of hemicellulose degrading enzymes with commercial enzyme solutions have been limited and investigation of these solutions in select combinations, together with pineapple pomace substrate, allows for novel research. The use of synergistic combinations of purified cellulosomal enzymes has previously been shown to be effective at releasing reducing sugars from agricultural wastes. For the present study, MannanaseA and XylanaseA from Clostridium cellulovorans were heterologously expressed in Escherichia coli BL21 (DE3) cells and purified with immobilised metal affinity chromatography. These enzymes, in addition to two commercially available enzyme solutions (Celluclast 1.5L® and Pectinex® 3XL), were assayed on defined polysaccharides that are present in pineapple pomace to determine their substrate specificities. The degree(s) of synergy and specific activities of selected combinations of these enzymes were tested under both simultaneous and sequential conditions. It was observed that several synergistic combinations of enzyme solutions in select ratios, such as C20P60X20 (20% cellulose, 60% pectinase and 20% xylanse), C20P40X40 (20% cellulose, 40% pectinase and 40% xylanase) and C20P80 (20% cellulose, 80% pectinase) with pineapple pomace could both decrease the protein loading, while raising the level of activity compared to individual enzyme solutions. The highest quantity of reducing sugars to protein weight used on pineapple pomace was recorded at 3, 9 and 18 hours with combinations of Pectinex® 3XL and Celluclast 1.5L®, but for 27 h it was combinations of both these commercial solutions with XynA. The contribution of XynA was significant as C20P60X20 displayed the second highest reducing sugar production of 1.521 mg/mL, at 36 h from 12.875 μg/mL of protein, which was the second lowest protein loading. It was also shown that certain enzyme combinations, such as Pectinex® 3XL, Celluclast 1.5L® and XynA, did not generate synergy when combined in solution at the initial stages of hydrolysis, and instead generated a form of competition called anti-synergy. This was due to Pectinex® 3XL which had anti-synergy relationships in select combinations with the other enzyme solutions assayed. It was also observed that the degree of synergy and specific activity for a combination changed over time. Some solutions displayed the highest levels of synergy at the commencement of hydrolysis, namely Celluclast 1.5L®, ManA and XynA. Other combinations exhibited the highest levels of synergy at the end of the assay period, such as Pectinex® 3XL and Celluclast 1.5L®. Whether greater synergy was generated at the start or end of hydrolysis was a function of the stability of the enzymes in solution and whether enzyme activity increased substrate accessibility or generated competition between enzymes in solution. Sequential synergy studies demonstrated an anti-synergy relationship between Pectinex® 3XL and XynA or ManA, as well as Pectinex® 3 XL and Celluclast 1.5L®. It was found that under sequential synergy conditions with Pectinex® 3 XL, XynA and ManA, that anti-synergy could be negated and high degrees of synergy attained when the enzymes were added in specific loading orders and not inhibited by the presence of other active enzymes. The importance of loading order was demonstrated under sequential synergy conditions when XynA was added before ManA followed by Pectinex® 3 XL, which increased the activity and synergy of the solution by 50%. This equates to a 60% increase in reducing sugar release from the same concentrations of enzymes and emphasises the importance of removing anti-synergy relationships from combinations of enzymes. It can be concluded that a C20P60X20 combination (based on activity) can both synergistically increase the reducing sugar production and lower the protein loading required for pineapple pomace hydrolysis. This study also highlights the importance of reducing anti-synergy in customised enzyme cocktails and how sequential synergy can demonstrate the order in which a lignocellulosic waste is degraded.

Orientador: Marcelo Brocchi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T19:14:52Z (GMT). No. of bitstreams: 1 Magalhaes_BeatrizLeite_M.pdf: 10407212 bytes, checksum: 966f327095d58a7872d7988a852b0612 (MD5) Previous issue date: 2015 / Resumo: Atualmente, o maior desafio da indústria de biotecnologia é a produção de combustíveis e compostos de interesse petroquímico, a partir de fontes renováveis, de forma economicamente viável. Dentre estes compostos destaca-se o butanol, um importante precursor químico industrial e com potencial para ser utilizado como combustível. O butanol pode ser produzido a partir de derivados de petróleo ou naturalmente por fermentação de espécies de clostrídio solventogênicas. Este processo fermentativo apresenta como principais produtos acetona, butanol e etanol (ABE), sendo, por isso, conhecido como fermentação ABE. Atualmente, a prática da fermentação ABE em escala industrial apresenta como principais obstáculos o alto custo dos substratos utilizados como matéria-prima e o seu baixo desempenho fermentativo. Neste contexto, o uso de hidrolisado de palha de cana-de-açúcar, um substrato considerado abundante e barato, poderia resolver em parte o problema da viabilidade econômica da fermentação ABE. Porém, para a geração deste hidrolisado, sua fonte de material lignocelulósico deve passar por duas etapas: pré-tratamento e hidrólise. Após este processamento, o hidrolisado gerado se caracteriza por ser uma mistura de hexoses e pentoses, mas também de inibidores de crescimento, o que representa um empecilho para a utilização deste material em uma fermentação. Assim, a busca e seleção de micro-organismos capazes de metabolizar diferentes açúcares e que sejam tolerantes aos inibidores presentes no hidrolisado, é visto como uma estratégia sustentável e barata para viabilizar a utilização de hidrolisados lignocelulósicos para a produção de químicos e combustíveis. Nesse contexto, este projeto visou o estabelecimento de uma condição onde fosse possível a produção microbiológica de n-butanol, a partir de hidrolisado lignocelulósico, com alto rendimento e produtividade. Para isso, o projeto contemplou a seleção de linhagens potenciais, o que resultou na escolha duas linhagens: Clostridium saccharoperbutylacetonicum DSM 14923, devido a sua alta produção de butanol, e Clostridium saccharobutylicum DSM 13864, por mostra-se capaz de co-fermentar glicose e xilose e apresentar maior robustez aos inibidores presentes no hidrolisado lignocelulósico. Além disso, foi realizada a otimização do meio e forma de cultivo para a obtenção de uma maior tolerância aos inibidores dos hidrolisados lignocelulósicos. Através desta abordagem, foi possível atingir uma melhora de 8 e 3,3 vezes na produção de butanol pelas linhagens C. saccharoperbutylacetonicum e C. saccharobutylicum, respectivamente. Além disso, com este meio otimizado foi possível a realização do cultivo das linhagens em maiores concentrações de hidrolisado. Por meio de ensaios fermentativos determinou-se que a linhagem C. saccharobutylicum DSM 13864 se destaca pela sua melhor performance em hidrolisado lignocelulósico, apresentando alto consumo de açúcar inclusive em altas concentrações deste substrato, sendo portanto a linhagem mais adequada para a fermentação neste substrato. Por outro lado, a concentração de butanol produzida ainda tem muito para ser melhorada indicando que o metabolismo desta linhagem em hidrolisado lignocelulósico precisa ser melhor compreendido. Ao final do trabalho, além da indicação da linhagem e o meio de cultivo otimizado para a produção de n-butanol a partir de hidrolisado lignocelulósico, geraram-se dados e resultados básicos que poderão ser empregados na produção de butanol em escala industrial / Abstract: Nowadays the production of fuels and petrochemical compounds from renewable sources with high yield and productivity is one of the biggest challenges of the biotechnology industry. Among these petrochemical compounds, butanol stands out as an important industrial chemical and because of its potential to be used as an alternative fuel. Butanol can be produced either from petroleum derivatives, as naturally by anaerobic fermentation using solventogenic clostridia. This fermentation process is known as ABE fermentation because it has as main products acetone, butanol and ethanol (ABE). Currently, the main obstacles to butanol production on industrial scale are the high cost of substrates and the low fermentation performance. In this context, the use of hydrolysate from sugarcane straw, considered an abundant and cheap substrate, could solve in part the problem of the economic viability of the ABE fermentation. However, for the generation of this hydrolyzate, the row material needs a pre-treatment step followed by hydrolysis. After this processing, the generated hydrolyzate is characterized by being a mixture of hexoses and pentoses sugars and by the presence of certain inhibitors of growth, which represents an obstacle to the use of this material in a fermentation. Thus, the search and selection of microorganisms able to metabolize different sugars and tolerant or resistant to the inhibitors present in the hydrolyzate, is seen as an inexpensive and sustainable strategy to enable the use of lignocellulosic hydrolyzates as feedstock for the production of biochemicals and biofuels. Then, the project had as aim the establishment of a condition where the microbiological production of n-butanol is possible, from lignocellulosic hydrolysate, with high yields and productivities. To achieve this objective, the project contemplated the screening of potential strains, resulting in the selection of strains: Clostridium saccharoperbutylacetonicum DSM 14923, outlined by its high butanol production, and Clostridium saccharobutylicum DSM 13864, outlined by its capacity of co-fermenting glucose and xylose. In addition, it was performed the culture medium optimization to obtain a greater tolerance to lignocellulosic hydrolyzate. Through this approach, it was possible to achieve 8 and 3.3-fold improvement in the production of butanol by the strains C. saccharoperbutylacetonicum and C. saccharobutylicum, respectively. Moreover, with this optimized medium, it was possible to perform the cultivation of these strains in higher concentrations of lignocellulosic hydrolysates. Through fermentation tests, it was determined that C. saccharobutylicum DSM 13864, among the others strains tested, has the best performance in lignocellulosic hydrolyzate, with a high sugar consumption even at high concentrations of these substrate, being the most suitable strain for the fermentation at this substrate. On the other hand, the concentration of butanol produced still can be improved, indicating that much remains to be elucidated about the metabolism of this strain in lignocellulosic hydrolyzate. At the end of the work, in addition of the optimization of the culture cultivation and the indication of the most adequate strain for fermentation in lignocellulosic hydrolysates, all the data and basic results generated can be used for the butanol production on industrial scale / Mestrado / Genetica de Microorganismos / Mestra em Genética e Biologia Molecular