Atualmente, o aumento da preocupação com a sustentabilidade ambiental, alinhado às perspectivas de esgotamento das reservas de petróleo, tem direcionado às buscas por fontes renováveis de energia. O emprego de resíduos agroindustriais, principalmente de usinas sucroalcooleiras destaca-se como sendo uma alternativa para a produção de etanol de segunda geração. Dentre as metodologias aplicadas para disponibilização dos açúcares fermentescíveis está a hidrólise enzimática. Ainda, para facilitar esta etapa e torná-la mais acessível, submete-se, previamente, o material lignocelulósico a um pré-tratamento, com o objetivo de contribuir com a susceptibilidade da celulose a ataques enzimáticos. No entanto, devido à complexidade das estruturas lignocelulósicas, os processos de hidrólise e pré-tratamento precisam se tornar mais eficientes e economicamente viáveis. Desta forma, o objetivo desse trabalho foi avaliar e caracterizar os pré-tratamentos hidrotérmico e organossolve (etanol 50%), isoladamente, e estes combinados em diferentes condições, assim como a influência destes procedimentos na estrutura e composição da biomassa, bem como na hidrólise enzimática. Os resultados demonstraram que os pré-tratamentos hidrotérmicos a 160 ºC nas condições analisadas foram pouco efetivos na melhora do acesso enzimático durante a etapa de hidrólise, pois atuaram de maneira branda na parede celular, pouco solubilizando a hemicelulose e lignina, conforme as análises físicas comprovaram. Os tratamentos combinados hidrotérmico 30 min e 60 min a 160 ºC seguidos pelo organossolve por 150 min apresentaram semelhança morfológica e alta solublização da lignina e hemicelulose, justificando os valores de hidrólise. Nossos resultados abrem perspectivas de novos estudos que visam a otimização dos pré-tratamentos hidrotérmicos e organossolve, além da compreensão das alterações composicionais e morfológicas que levam à melhoria da hidrólise enzimática na biomassa lignocelulósica. / The concerns with environmental sustainability and perspectives of petroleum reserves depletion motivated exploration of new and sustainable energy sources. In this context, renewable energies start to receive significant attention in the world´s energy matrix, with biofuels playing a special role. The use of agro-industrial residues, mainly from the sugarcane industry, stands out as a viable alternative for the production of second-generation ethanol. The enzymatic hydrolysis of the biomass has a number of advantages for polysaccharides depolimerization, such as high substrate specificity, low environmental impact and lack of corrosion issues. To further facilitate this procedure and to make biomass more accessible, the lignocellulosic material has to be previously submitted to a pretreatment in order to increase the cellulose accessibility and susceptibility to the enzymatic action. This process aims at the disorganization of the chemical structure of the lignocellulosic matter, facilitating the further steps of hydrolysis and fermentation. Due to the complexity of the lignocelluloses structures, their pretreatment and hydrolysis processes have to become more efficient and economically viable to be efficiently applied at an industrial scale. Therefore, the objective of this work is to evaluate the hydrothermal and organosolv (50% ethanol) pretreatments, separately and combined in different conditions, and the influence of these procedures on the structure and composition of the biomass and on the efficiency of enzymatic hydrolyses. Our results demonstrated that the hydrothermal pretreatments at 160ºC within the analyzed reaction conditions had minor effects on improving the enzymatic efficiency, being not harsh enough to introduce significant modifications of the cell wall composition and structure, as demonstrated by our physical and chemical analyses. The combined hydrothermal treatments lasting 30 min and 60 min at 160ºC followed by the organosolv step for 150 min resulted in significant morphological changes and high lignin and hemicelluloses solubilization, resulting in an efficient enzymatic hydrolysis. Our results open perspectives of further studies aimed at optimization of hydrothermal and organosolv pretreatments and comprehension of compositional and morphological changes which lead to improved enzymatic hydrolysis of the lignocelulosic biomass.

O uso de resíduos agrícolas como fonte de carbono para a geração de energia renovável parece uma solução promissora para reduzir nossa dependência em combustíveis fósseis. Na natureza, como na compostagem, comunidades microbianas formam redes metabólicas complexas que degradam eficientemente a biomassa disponível através de um conjunto de enzimas sinérgicas. Entretanto, a desconstrução da lignocelulose continua uma desafio para a indústria devido a natureza recalcitrante do substrato e a baixa atividade das enzimas, aumentando o preço do biocombustível produzido. Estudos de metagenômica e metatranscriptômica de comunidades microbianas complexas tornam possível acessar as funções metabólicas empregadas por consórcios lignocelulolíticos e revelar novos biocatalisadores que podem melhorar a conversão industrial da lignocelulose. Aqui, através de uma abordagem metagenômica, foi examinada a diversidade de microrganismos obtidos em condições laboratoriais quando um meio definido ou um complexo foi usado no seu crescimento. Em seguida, a comunidade microbiana derivada de compostagem foi crescida em meio mínimo com bagaço de cana-de-açúcar como única fonte de carbono. A degradação do substrato foi monitorada e o metatranscriptoma da cultura resultante foi sequenciado, seguido pela seleção e caracterização funcional de vários alvos. Durante as cinco semanas de estudo, a comunidade microbiana crescida em meio mínimo mostrou maior diversidade e enriquecimento em microrganismos capazes de degradar a lignocelulose do que a comunidade microbiana crescida no meio complexo. A partir do metatranscriptoma foi descoberta a primeira hidrolase de glicosídeo da família 11 com atividade exoxilanase (C21). A estrutura cristalográfica da C21, refinada à 1,76 Å, revelou que a atividade exoxilanase observada se deve a presença de duas alças que não estão presentes nas demais estruturas dos membros da família 11 de hidrolase de glicosídeo depositadas até então. A adição da C21 a um coquetel comercial provocou um aumento na velocidade de hidrólise do Avicel quando na presença de xilooligômeros. As análises metagenômica e metatranscriptômica da comunidade microbiana proveniente da compostagem revelaram que o uso de um meio definido pode deslocar espécies generalistas, levando a uma fonte enriquecida para explorar enzimas com aplicação biotecnológica. Também demonstrou a diversidade de mecanismos envolvidos na degradação in situ da lignocelulose. / Using of the globally abundant crop residues as carbon source for energy generation seems a promising solution to reduce our dependency on fossil fuels. In nature, such as in compost habitats, microbial communities create complex metabolic networks that efficiently degrade the available plant biomass using a set of synergistic enzymes. However, deconstruction of lignocellulose remains a challenge for industry due to recalcitrant nature of the substrate and enzymes low activity, raising the price of the produced biofuel. Metagenomics and metatranscriptomics studies on complex microbial communities can assess the metabolic functions employed by the lignocellulolytic consortia and unveil novel biocatalysts that could improve industrial lignocellulose conversion. Here, using 16S rRNA amplicon metagenomic approach, we examined the diversity of microorganisms obtained in the laboratory setting when a nutrient-limited or nutrient-rich media are used. Then, a microbial community derived from compost was grown in minimal medium with sugarcane bagasse as a sole carbon source. The substrate degradation was monitored and the metatranscriptome from the resulting cultures was sequenced; several target genes were selected and functional characterized. During a five-week time course, the microbial community grown in minimal medium showed greater diversity and enrichment in lignocellulose-degrading microorganisms than the one grown in nutrient rich medium. Metatranscriptomics analysis revealed the first glycoside hydrolase from family 11 with exo-xylanase activity (C21). C21 crystal structure, refined at 1.76 Å, explained the molecular basis of exo-xylanase activity due to two extra loops previously unseen in the other reported structures from members from glycoside hydrolase family 11. A supplementation of commercial enzyme mix with C21 showed improvement in Avicel hydrolysis in the presence of inhibitory xylooligomers. The combination of metagenomic and metatranscriptomic analysis of compost-derived microbial community showed that nutrient-limited medium may displace bacterial generalist species, leading to an enriched source for mining novel enzymes for biotechnology applications. It also unveiled a diversity of mechanisms involved in lignocellulose degradation in situ.

The increase of petroleum cost as well as global warming and climate change result in investigation to discover new renewable energy resources. Bioenergy is one of the most important sources that is concerning the scientists and industrial sector. Although bioethanol had to be known as one of the most important renewable energy sources in order to reduce greenhouse gases and global warming, there is a limited number of publications reporting on them. In this review, a brief overview is offered about bioethanol production from algae. It can be given a deeper insight in dificulties and promising potential of bioethanol from algae. / Sự gia tăng giá nhiên liệu hóa thạch cùng với cảnh báo toàn cầu về biến đổi khí hậu hướng đến việc nghiên cứu tìm ra những nguồn năng lượng có thể tái tạo. Năng lượng sinh học là một trong những nguồn quan trọng được các nhà khoa học và doanh nghiệp quan tâm. Mặc dù ethanol sinh học đã được biết đến như là một trong những dạng năng lượng tái tạo quan trọng nhất để giảm thiểu các khí nhà kính và cảnh báo toàn cầu, nhưng chỉ có một số ít bài báo về nó. Trong bài tổng quan này, chúng tôi giới thiệu vắn tắt việc sản xuất ethanol sinh học từ tảo. Nó đưa ra cái nhìn sâu hơn về những khó khăn và tiềm năng hứa hẹn của sản xuất ethanol sinh học từ tảo.

In this dissertation, the molecular behaviors of water/ethanol mixtures of different weight fractions inside Au nanotubes of different radii at steady state were investigated by molecular dynamics simulation. Five weight fractions of water/ethanol (0/100, 100/0, 25/75, 50/50, and 75/25) and three radii of Au nanotubes (13, 22, and 31.1 Å) were considered in order to understand the effects of Au nanotube size and water/ethanol fraction on the structural and dynamical behaviors of the water and ethanol molecules. The density profiles show two shell-like formations inside the Au nanotubes because water molecules prefer to adsorb on the wall of Au nanotube. According to the density distribution, the space inside Au nanotubes can be divided into three regions, those of contact, transition, and bulk regions, in order from the interior wall surface to the nanotube center. The bulk region has a lower local weight fraction compared to the system water/ethanol weight fraction. In addition, the local water/ethanol weight fraction in the contact region is higher than that of the system. When the system water/ethanol weight fraction becomes higher, the local water/ethanol weight fraction also becomes higher. In 25/75, 50/50, and 75/25 weight fraction mixtures, the number of H-bonds per water and per ethanol are different from those of pure 100% water and 100% ethanol in the Au nanotube due to the nanoconfinement effect. Moreover, the distribution of number of H-bonds in regions where there is only one material will be similar to the distribution in the corresponding region of the pure material, whether 100% water or ethanol. In all regions, the probability to form different H-bonds is affected significantly by the local weight fraction of water/ethanol. Three radii of Au nanotubes (13, 22, and 31.1 Å) were considered in order to understand the effects of Au nanotube size and water/ethanol fraction on the structural and dynamical behaviors of the water and ethanol molecules. In the transition and bulk regions, diffusion coefficients for water and ethanol molecules become higher due to the weak interaction with Au atoms. The values of diffusion coefficients for water molecules in the contact regions are much lower than for those in other regions and are similar for different water/ethanol weight fractions due to the strong interaction with Au atoms. When the radius of the Au nanotube becomes larger, the values of local weight fraction inside the larger radius Au nanotube become higher than those inside small radius Au nanotubes because the ratio of water number to the nanotube inner surface area becomes higher. In addition, water inside a larger radius Au nanotube has a shorter water-water hydrogen bond lifetime (H-bond) in the contact region because the smaller curvature causes weaker interaction with Au atoms.

This thesis is a theoretical and empirical examination of the developmentof bioethanol markets since 2005 when sustainability regulations forbiofuels were introduced globally. The experiences of Brazil and Sweden,and the influence of European regulations on the development ofbioethanol markets receive special attention. The work is based onprimary and secondary data sources gathered between 2009 and 2014,including interviews, field research, data from public and private sources,as well as an extensive literature review. The thesis uses case examples ofcountries that have adopted bioethanol as a transport fuel, such as Braziland Sweden.The research is structured using a bottom-up approach, and addressesthree specific angles of the complex issue of how bioethanol marketshave developed under sustainability requirements.The first part introduces an economic sustainability view of ethanol. Thecharacteristics of bioethanol fuel are presented together with conceptsand a theoretical framework for analysing biofuel sustainability. Policytools are also discussed, particularly those used to introduce fuel ethanolin the transport sector. The discussion is centred on the competitionbetween ethanol and gasoline, considering the hypothesis that consumersare sensitive to prices and tend to choose fuels based on their cost-perenergyunit. The analysis is supported by the case examples of Brazil andSweden, with special focus on the delicate balance between fueleconomies of bioethanol and gasoline systems in the face of differentways oil products are priced in those countries. Findings show thatdrivers tend to choose between bioethanol (E85/E100) or gasoline (E5-E25) depending on the relative prices between the two fuels. Theresearch results suggest that different pricing strategies for bioethanoland gasoline affect how consumers perceive the attractiveness of eachfuel. The examples of E100 in Brazil and E85 in Sweden provide insightson the elastic consumer behaviour that new markets may experience,serving to guide strategies in different contexts.The second part of this work bridges experiences in national contextswith the recent trend for biofuel sustainability regulation in internationalmarkets. Based on the hypothesis that the ethanol industry is responsiveto sustainability regulations, an examination of the development of theiiBrazilian bioethanol industry is carried out. This provides a comparisonframework drawing patterns between the industry's reaction to nationalregulations (past) and international regulations (recent). For this purpose,a comparison between the European sustainability requirements forethanol and the industry’s status quo is explored. Findings show that theEU sustainability criteria for biofuels are likely to have three effects onthe bioethanol industry: (i) compliance through incrementalimprovements in sustainability practices and certification; (ii) riskdiversification by engaging in multi-output production models; and (iii)market leakage towards less-regulated markets.The third part of the thesis brings together the first two parts. Itexamines how in a fuel competition context, the incorporation of costsrelated to sustainability certification can change the attractiveness ofhigh-bioethanol blends for consumers. The model of sustainabilityadopted by major international markets is based on regulations enforcedby mandatory certification. As biofuel market share increased, producerswere faced with costs for sustainability certification in order to obtainmarket access. While it was expected that ‘sustainably’ produced biofuelswould be rewarded with higher prices in the EU, this work found thatprice premiums for ethanol have in general been very small or inexistent,with certified fuels becoming the new norm in the market. New costsbrought into the market through sustainability certification can make itdifficult to balance between national policies heavily reliant on consumerchoice between fuels (and associated price-elasticities), and thedeployment of high blends of ethanol, such as E100 and E85.By analysing the three aspects (consumer behaviour and marketdynamics for ethanol in Brazil and Sweden, the introduction ofsustainability criteria for biofuels, and the implications of sustainabilityfor consumer choice between fuels) this work seeks to increaseunderstanding of the highly complex issue of biofuel market formationin the face of sustainability requirements. The key finding is thatsustainability certification has a cost, which needs to be orchestrated withother sectors of the economy to achieve the desired objectives. Thisthesis suggests that crucial areas of economic and environmentalsustainability have been often dealt with separately in biofuelpolicymaking, which has created weaknesses that deserve attention infuture policy efforts in order to improve biofuel systems. / <p>QC 20150401</p>

The growing demand for energy in the world, the implications of climate change, the increasing damages to our environment and the diminishing fossil fuel reserves have created the appropriate conditions for renewable energy development. Biofuels such as bioethanol can be produced by breaking down the lignocellulosic structure of plant materials to release fermentable sugars. Sweet sorghum bagasse has been shown to be an important lignocellulosic crop residue and is potentially a significant feedstock for bioethanol production. The aim of this study was to investigate suitable microwave assisted pretreatment conditions of sweet sorghum bagasse for bioethanol production. A chemical pretreatment process of sweet sorghum bagasse, using different concentrations (1 to 7 wt%) of sulphuric acid (H2SO4) and calcium hydroxide (Ca (OH)2) was applied to break up the lignocellulosic matrix of sweet sorghum bagasse. The pretreated broth, which contained pentose and hexose sugars, was fermented using a combination of Zymomonas mobilis ATCC31821 and Saccharomyces cerevisiae to produce bioethanol at pH 4.8 and 32oC for 24 hours. The highest reducing sugar yield of 0.82 g/g substrate was obtained with microwave irradiation at 180 W for 20 minutes in a 5 wt% sulphuric acid solution. The highest ethanol yield obtained was 0.5 g/g from 5 wt% H2SO4 pretreated bagasse at 180 W using a 10:5% v/v of Saccharomyces cerevisiae to Zymomonas mobilis ratio, whereas for 3 wt% Ca (OH)2 microwave pretreatment, a sugar yield of 0.27 g/g substrate was obtained at 300 W for 10 minutes. Thereafter, an ethanol yield of 0.13 g/g substrate was obtained after 24 hours of fermentation when using a 10:5% v/v of Saccharomyces cerevisiae to Zymomonas mobilis ratio. The effect of microwave pretreatment on the bagasse was evaluated using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The reducing sugars formed were quantified using High Performance Liquid Chromatography (HPLC). The results showed that microwave pretreatment using 5 wt% H2SO4 is a very effective pretreatment that can be used to obtain sugars from sweet sorghum bagasse. The analytic results also showed physical and functional group changes after microwave pretreatment. This confirms that microwave irradiation is very effective in terms of breaking up the lignocellulose structure and improving fermentable sugar yield for fermentation. Bioethanol yields obtained from microwave pretreatment using different solvents also show that Saccharomyces cerevisiae and Zymomonas mobilis ATCC31821 is a good combination for producing ethanol from sweet sorghum bagasse. Sweet sorghum bagasse is clearly a very effective and cheap biomass that can be used to produce bioethanol, since very high yields of fermentable sugars were obtained from the feedstock. / Thesis (MSc (Engineering Sciences in Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.

The growing demand for energy in the world, the implications of climate change, the increasing damages to our environment and the diminishing fossil fuel reserves have created the appropriate conditions for renewable energy development. Biofuels such as bioethanol can be produced by breaking down the lignocellulosic structure of plant materials to release fermentable sugars. Sweet sorghum bagasse has been shown to be an important lignocellulosic crop residue and is potentially a significant feedstock for bioethanol production. The aim of this study was to investigate suitable microwave assisted pretreatment conditions of sweet sorghum bagasse for bioethanol production. A chemical pretreatment process of sweet sorghum bagasse, using different concentrations (1 to 7 wt%) of sulphuric acid (H2SO4) and calcium hydroxide (Ca (OH)2) was applied to break up the lignocellulosic matrix of sweet sorghum bagasse. The pretreated broth, which contained pentose and hexose sugars, was fermented using a combination of Zymomonas mobilis ATCC31821 and Saccharomyces cerevisiae to produce bioethanol at pH 4.8 and 32oC for 24 hours. The highest reducing sugar yield of 0.82 g/g substrate was obtained with microwave irradiation at 180 W for 20 minutes in a 5 wt% sulphuric acid solution. The highest ethanol yield obtained was 0.5 g/g from 5 wt% H2SO4 pretreated bagasse at 180 W using a 10:5% v/v of Saccharomyces cerevisiae to Zymomonas mobilis ratio, whereas for 3 wt% Ca (OH)2 microwave pretreatment, a sugar yield of 0.27 g/g substrate was obtained at 300 W for 10 minutes. Thereafter, an ethanol yield of 0.13 g/g substrate was obtained after 24 hours of fermentation when using a 10:5% v/v of Saccharomyces cerevisiae to Zymomonas mobilis ratio. The effect of microwave pretreatment on the bagasse was evaluated using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The reducing sugars formed were quantified using High Performance Liquid Chromatography (HPLC). The results showed that microwave pretreatment using 5 wt% H2SO4 is a very effective pretreatment that can be used to obtain sugars from sweet sorghum bagasse. The analytic results also showed physical and functional group changes after microwave pretreatment. This confirms that microwave irradiation is very effective in terms of breaking up the lignocellulose structure and improving fermentable sugar yield for fermentation. Bioethanol yields obtained from microwave pretreatment using different solvents also show that Saccharomyces cerevisiae and Zymomonas mobilis ATCC31821 is a good combination for producing ethanol from sweet sorghum bagasse. Sweet sorghum bagasse is clearly a very effective and cheap biomass that can be used to produce bioethanol, since very high yields of fermentable sugars were obtained from the feedstock. / Thesis (MSc (Engineering Sciences in Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.

Bioethanol is an appealing alternative to petroleum-based liquid fuel due to drivers such as environmental regulations and government mandates. Second generation lignocellulosic feedstocks are abundant, but their resistance to hydrolysis continues to be problematic. Different pretreatments have been proposed to increase cellulose reactivity. Softwood pine autohydrolyzed at different severities was subjected to further treatment to increase fibre reactivity. Liquid hot water is most effective at removing barriers, with the highest increase in sugar yield after enzymatic hydrolysis. Alkaline (NaOH) is found to be the worst option compared to dilute acid and organosolv. In addition, higher chemical concentrations and longer treatment times do not guarantee higher enzymatic hydrolysis yield. Process modifications such as fiber washing and multistage enzymatic hydrolysis are observed to be effective at increasing yield. However, more research is required to bring the enzymatic hydrolysis yield to a level where commercialization is feasible.

Bioethanol is an appealing alternative to petroleum-based liquid fuel due to drivers such as environmental regulations and government mandates. Second generation lignocellulosic feedstocks are abundant, but their resistance to hydrolysis continues to be problematic. Different pretreatments have been proposed to increase cellulose reactivity. Softwood pine autohydrolyzed at different severities was subjected to further treatment to increase fibre reactivity. Liquid hot water is most effective at removing barriers, with the highest increase in sugar yield after enzymatic hydrolysis. Alkaline (NaOH) is found to be the worst option compared to dilute acid and organosolv. In addition, higher chemical concentrations and longer treatment times do not guarantee higher enzymatic hydrolysis yield. Process modifications such as fiber washing and multistage enzymatic hydrolysis are observed to be effective at increasing yield. However, more research is required to bring the enzymatic hydrolysis yield to a level where commercialization is feasible.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-24T16:05:47Z No. of bitstreams: 1 DOUGLAS ALEXANDRE SARAIVA LEÃO - TESE PPGEP 2014..pdf: 1444579 bytes, checksum: 17272fc64c2d76578d08692395e65bfe (MD5) / Made available in DSpace on 2018-04-24T16:05:47Z (GMT). No. of bitstreams: 1 DOUGLAS ALEXANDRE SARAIVA LEÃO - TESE PPGEP 2014..pdf: 1444579 bytes, checksum: 17272fc64c2d76578d08692395e65bfe (MD5) Previous issue date: 2014-08-29 / A matriz energética brasileira é uma das mais limpas do mundo e, atualmente, mais de 45% de toda energia consumida no país provém de fontes renováveis. O álcool é um combustível que já tem o seu lugar assegurado nessa matriz, diante disso, o etanol de segunda geração pode se tornar uma fonte de energia para o Brasil e o mundo. Uma planta promissora na produção de bioetanol é o sisal, pois possui 90 % de açúcares fermentáveis e 10 % a mais de celulose que a cana-de-açúcar, além disso, o Brasil é o maior produtor de sisal do mundo. O objetivo do trabalho foi caracterizar a fibra do sisal, quanto à concentração de açucares por CLAE e a composição físico-química e térmica por meio de métodos convencionais e das técnicas de DRX, TG, DSC e MEV; determinar as melhores condições para o pré-tratamento ácido seguido de básico e realizar a hidrólise ácida e enzimática. Além de fermentar o licor hidrolisado de maior concentração de glicose. Para avaliar o pré-tratamento e a hidrólise ácida, usou-se duas granulometrias 0,21 e 0,49 mm da fibra e verificou-se os efeitos da temperatura e concentração de ácido na produção da xilose e glicose, utilizando como ferramenta um planejamento experimental fatorial. Para avaliar a hidrólise enzimática, verificou-se, por meio da aplicação de um planejamento experimental fatorial, o efeito da carga enzimática e a razão massa seca de fibra de sisal e extrato enzimático. Foram usadas as enzimas comerciais Celluclast 1.5L da Novozyme e betaglicosidase da Proenzyme. O pré-tratamento ácido seguido de básico mostrou-se bastante eficiente em concentrar a celulose, pela retirada da hemicelulose e lignina, provocando um aumento da celulose de 54 para 83%. Evidenciou-se a cristalinidade da fibra de sisal, comprovada por Difração de Raios X, modificou-se a morfologia da fibra, verificada por Microscopia Eletrônica de Varredura, e, por meio da Termogravimetria e Calorimetria Exploratória Diferencial comprovou-se a degradação da hemicelulose e lignina. Com o material pré-tratado, o processo de hidrólise enzimática foi mais eficiente na sacarificação, não ocorrendo eficácia para a hidrólise ácida. A hidrólise ácida com o material sem prétratamento provocou a sacarificação da celulose, no entanto, os valores obtidos de glicose são menores do que os obtidos na hidrólise enzimática que foi de 39000 ± 2700 mg.L-1. O licor hidrolisado enzimaticamente foi usado para a produção de etanol por meio de fermentação submersa, utilizando S. cerevisiae (Y904), desta forma, obteve-se uma produção de etanol de 19,4 g.L-1 em 7,3 h de fermentação. O monitoramento da cinética fermentativa em reator de batelada permitiu a avaliação do consumo de glicose, produção de etanol e massa microbiana. Em nível laboratorial a taxa especifica máxima de crescimento foi de 0,3 h-1, 96% de rendimento e produtividade de 2,7 g. L-1.h-1. / The Brazilian energy matrix is one of the cleanest in the world and currently more than 45% of all energy consumed in the country comes from renewable sources. The alcohol is a fuel already has its place assured in the Brazilian energy matrix, therefor the second-generation ethanol can become a source of energy for Brazil and the world. A promising plant to produce bioethanol is the sisal because it has 90% of fermentable sugars and 10% more cellulose than sugar cane, in addition to Brazil is the world's largest sisal producer. The objective was to characterize the sisal fiber, as the concentration of sugars by HPLC and the physicochemical composition chemical and thermal by means of conventional methods and techniques XRD, TG, DSC and MEV; determine the best conditions for the pre-treatment followed by acid perform basic and acidic and enzymatic hydrolysis. In addition to ferment the hydrolyzate liquor higher concentration of glucose. To evaluate the pre-treating and the acid hydrolysis it was used two grain sizes 0.21 and 0.49 mm fiber and found the effects of temperature and the concentration of acid in the production of xylose and glucose using as a tool factorial design. To assess the enzymatic hydrolysis was verified by applying a factorial design, the load effect enzyme and the dry weight ratio of sisal fiber and enzyme extract. The were used commercial enzymes of Celluclast 1.5L and Novozyme beta-glucosidase proenzyme. The pretreatment followed basic acid proved to be very effective in concentrating cellulose, by removing the hemicellulose and lignin, resulting in an increase in cellulose from 54 to 83%. Revealed a crystallinity of sisal fiber, proven by X-ray diffraction, has changed the morphology of the fiber, verified by microscopy Scanning Electron, and by Thermogravimetry and Scanning Calorimetry Differential proved the degradation of hemicellulose and lignin. With the material pretreated the enzymatic hydrolysis process was more efficient in saccharification, not occurring efficiency for acid hydrolysis. Acid hydrolysis of the material without pretreatment caused saccharification of cellulose however the values obtained glucose are smaller than those obtained in the enzymatic hydrolysis was 39000 ± 2700 mg l-1. The enzymatically hydrolysed liquor was used to produce ethanol by through submerged fermentation using S. cerevisiae (Y904), this way was obtained an ethanol yield of 19.4 gL1 in 7.3h of fermentation. The monitoring fermentation kinetics in batch reactor allowed assessment of glucose uptake, ethanol and microbial mass. In laboratory level the maximum specific rate growth was 0.3 h-1, 96% yield and productivity 2.7 g.L-1.h-1.