Dissertations / Theses on the topic 'Sugars and lignin'

Sustainable waste treatment and lignin development strategies targeted for biorefineries will benefit industry, consumers, and the environment. This dissertation demonstrates the feasibility of a novel biochemical pathway capable of converting sugars and lignin sourced from biorefinery waste streams into microbial oils suitable for biodiesel, cosmetic, and biopharmaceutical applications. This biochemical pathway also presents interesting avenues for the commercial production of higher-value intermediate metabolites such as catechol, protocatechuate, pyruvate, and succinate. Alternatively, this dissertation also demonstrates a unique polymerization strategy for lignin that can be adopted towards the production of green polymeric biomaterials. Overall, these strategies jointly present intriguing routes for lignin valorization.

Lignocellulosic materials (LM) are an ever present renewable and available energy source. The energy stored by photosynthesis in the form of vegetation is about ten times more than world's annual energy consumption (Zsuffa, 1982). This source is the only alternative for chemical production after fossil fuels. Formation of organic acids (mainly acetic acid) from hemicellulose during steam treatment of LM leads to acid hydrolysis of cell wall components. Solubilization of hemicellulose and depolymerization of lignin are the most important changes that occur during the process. During hydrolysis of LM appreciable amounts of sugar degradation products, organic acids and phenolics are produced. Inhibitory effects of the compounds on yeast during alcoholic fermentation have been reported and several methods have been proposed to overcome the problem. Among the new compounds phenolics derived from lignin depolymerization have received most attention. Another problem during enzymic saccharification of cellulose is partial inactivation of cell free enzymes. The above mentioned constraints were investigated in this study.

Lignocellulosic bioethanol is currently being explored as a substitution to fossil fuels. Many lignocellulosic materials are being examined but the importance is to find those with attractive agro-energy features. Producing lignocellulosic ethanol is challenging because lignocellulosic biomass is resistant to chemical and biological degradation. To reduce biomass recalcitrance, a pretreatment stage is required. Pretreatment is considered to be the most intensive operating/operating cost component of cellulosic ethanol production. Therefore, research is heavily focused on understanding the effect of pretreatment technologies on the fundamental characteristics of lignocellulosic biomass. The first study in the thesis investigates Buddleja davidii as a potential biomass source for bioethanol production. The work focuses on the determination of ash, extractives, lignin, hemicellulose, and cellulose content in this plant, as well as detailed elucidation of the chemical structures of both lignin and cellulose by NMR spectroscopy. The study showed that B. davidii has several unique agro-energy features as well as some undesired characteristics. The second study presents research on the ethanol organosolv pretreatment (EOP) of B. davidii and its ability to produce enzymatically hydrolysable substrates. It was concluded that the removal of hemicellulose, delignification, reduction in the degree of polymerization (DP) of cellulose, and the conversion of crystalline cellulose dimorphs (Iα/Iβ) to the easily degradable para-crystalline and amorphous celluloses were the characteristics accounted for efficient enzymatic deconstruction of B. davidii after EOP. The third study provides a detailed elucidation of the chemical structure of ethanol organosolv lignin (EOL) of B. davidii by NMR spectroscopy. Such research was needed to understand the pretreatment mechanism in the context of delignification and alteration of the lignin structure. Future applications of the resulted EOL will be valuable for industrially viable bioethanol production process. EOP mainly cleaved β-O-4' interlinkages via homolysis, decreased the DP of lignin, and increased the degree of condensation of lignin. EOL had low oxygen content, molecular weight, and aliphatic OH as well as high phenolic OH, which are qualities that make it suitable for different co-product applications. The last study provides information on the anatomical characteristics of pretreated B. davidii biomass after EOP. The importance of this research was to further understand the alterations that occur to the cellular structure of the biomass which can then be correlated with its enzymatic digestibility. The results concluded that the physical distribution of lignin within the biomass matrix and the partial removal of middle lamella lignin were key factors influencing enzymatic hydrolysis.

Effective visible light photocatalysts for achieving organic reactions under mild conditions are long sought after and a rarely achieved aim in modern catalyst chemistry. Here, metal complexes and plasmonic metal NPs were assembled and used systematically for the first time as a novel photocatalyst to achieve this target. The new photocatalytic system was designed, established, and proved to be efficient in driving C-O bond cleavage of lignin model compounds and sugars dehydration to produce 5-HMF under visible light irradiation.

Os métodos analíticos empregados atualmente para a caracterização química de materiais lignocelulósicos foram desenvolvidos para a madeira e são empregados com pequenas modificações ao bagaço e à palha da cana-de-açúcar. A não existência de metodologia específica para estes materiais leva a obtenção de resultados inadequados e dificultam tanto o planejamento quanto a interpretação de resultados. Sendo assim, o objetivo principal deste trabalho é desenvolver metodologias analíticas específicas para a caracterização química da palha e do bagaço de cana-de-açúcar. A determinação de lignina foi estudada a partir da hidrólise e solubilização da celulose e hemiceluloses em solução de ácido sulfúrico. A fração insolúvel foi analisada por análise elementar, espectroscopia no infravermelho, espectrometria de ressonância magnética nuclear de C13 no estado sólido e análise termogravimétrica (TGA). Os açúcares hidrolisados e produtos derivados destes foram analisados por meio de cromatografia líquida de alta eficiência (CLAE). Foi realizada uma análise de holocelulose que é complementar à determinação de lignina. O procedimento consiste no tratamento do material lignocelulósico (pré-extraído com cicloexano/etanol) com solução de clorito de sódio em meio ácido. Os resultados obtidos não apresentaram similaridade nas correlações entre os métodos analíticos, entretanto mostraram que o bagaço integral e suas frações separadamente apresentam comportamentos diferentes, frente ao tratamento ácido, o que ressalta a necessidade de métodos analíticos específicos.
The analytical methods currently used for chemical characterization of lignocellulosic materials were developed for wood and are applied with minor modifications for sugar cane bagasse and straw analysis. The lack of specific methodology for these materials leads to inadequate results and hamper both the planning and the interpretation of results. Thus, the main aim of this work is to develop specific analytical methodologies to the chemical characterization of sugar cane bagasse and straw. The determination of lignin was studied by the hydrolysis and dissolution of the polysaccharide fraction in sulfuric acid solution. The insoluble fraction was analyzed by elemental analysis, Fourier Transform Infrared (FT-IR), Carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), Gel permeation chromatography (GPC) and Thermogravimetric analysis (TGA). The sugars and derivatives of these hydrolysates were analyzed by High performance liquid chromatography (HPLC). It was also performed a complementary analysis from the holocellulose content determinations in order to check the values obtained by the klason procedure. The results showed the dependence of sulfuric acid concentration on lignin content determinations and the role of condensation reactions in the lignin characteristics. Despite the similarities in chemical composition, klason lignins obtained from straw exhibited very low molar masses. Preliminary results obtained from holocellulose determinations showed also the need for optimized oxidation procedures in order to be successful applied to sugar cane bagasse analysis.

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O Brasil é o maior produtor mundial de cana-de-açúcar, e com isso é também o maior gerador de biomassa residual – bagaço e palha. Uma grande parte dessa biomassa é utilizada na co-geração de energia, sendo queimada nas caldeiras das usinas, porém ainda há um enorme excedente, gerando problemas ambientais e sociais. Por isso, é necessário desenvolver projetos para utilização desse material, com valor agregado. Uma das maneiras é a utilização dos compostos que compõem a fibra do bagaço: celulose, hemicelulose e lignina. Para viabilizar a utilização desses compostos são necessárias técnicas pouco nocivas e com custo reduzido. Além disso, é importante que durante o processo de extração, haja pouca alteração estrutural dos compostos, ou que as alterações sofridas sejam benéficas para sua utilização posterior. O presente trabalho visou desenvolver métodos diferentes de extração de uma das frações dessa fibra, a lignina, avaliando as alterações sofridas durante os processos de extração para um posterior uso dessas ligninas de acordo com suas características. Os três métodos foram Organossolv utilizando uma mistura de dioxano e ácido clorídrico, Organossolv utilizando etanol e o Álcali. A caracterização das ligninas extraídas foi realizada através de técnicas de análise térmica (TG-DTG/DTA), microscopia eletrônica de varredura com aplicação de campo (MEV-FEG), espectroscopia de infravermelho (FTIR), e ressonância magnética nuclear (RMN). Através dos resultados obtidos nas análises evidenciou-se uma alteração maior na lignina extraída pelo método Álcali, com maiores rupturas nas ligações aromáticas durante o processo de extração quando comparado com as ligninas obtidas pelos dois métodos Organossolv. As três ligninas contêm estruturas carbônicas diferentes entre si, sendo que a que mais se aproxima da lignina de origem é a obtida pelo método Organossolv com dioxano.
Brazil is the huge producer of sugarcane worldwide, and it is also the largest residual biomass generator - bagasse and straw. A large part of this biomass is used for energy co-generation, being burnt in the boilers of the plants, but there is still a huge surplus, generating environmental and social problems. So it is necessary to develop projects to use this material with aggregate value. One way is the use of compounds that make up the fiber of bagasse: cellulose, hemicellulose and lignin. To enable the use of these compounds are required little harmful techniques and low cost. Moreover, it’s important that during the extraction process there is little structural change of the compounds or that suffered changes are beneficial for later use. This study aimed to develop different methods of extracting a fraction of this fiber, the lignin, evaluating the changes done by the extraction processes for later use these lignins according to their characteristics. The three methods were Organossolv using a mixture of dioxane and hydrochloric acid, Organossolv using ethanol and Alkali. The characterization of the extracted lignins was performed by thermal analysis techniques (TG-DTG / DTA), scanning electron microscopy with field application (SEM-FEG), infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results obtained in the analysis revealed a greater change in the lignin extracted by the alkali method with larger breaks in aromatic bonds during the extraction process compared with the lignins obtained by the two methods Organossolv. The three lignins contain carbonic structures different from each other, and that is closest to the origin of lignin is obtained by Organossolv method with dioxane.

Universidade Federal do CearÃ
The present work aimed at the production of lignosulfonate, based in the lignin extracted from sugarcane bagasse-cane for using in phenolic resins. The extraction of lignin was carried out using the acetosolv process, which was optimised with a central composite design 22 to evaluate the effects of reaction time and temperature on the extraction yield, weight-average (M ̅w) and number-average (M ̅n) molecular weights, relative content of total hydroxyl, phenolic hydroxyl and methoxyl groups. The lignins obtained under conditions that maximized the extraction yield and showed better structural and thermal characteristics were sulfonated to obtain the lignosulfonates. The structural and thermal characteristics of the lignins and lignosulfonates were determined by FT-IR, GPC, 1H-NMR and 13C-NMR, DSC and TGA. The results show that the best extraction yield (64.5%) was obtained with 95% (w/w) of acetic acid, the addition of 0.1% HCl, at a temperature of 187 ÂC and reaction time of 40 min. However, with the same concentration of acetic acid and reaction time of 15 min at 187 ÂC, the extraction yield decreased to 55.6% Â 4.5%, without significant reduction. Furthermore, the increase in temperature of 187 ÂC to 205 ÂC was not enough to cause a significant increase in the relative content of hydroxyls and reduction of the relative content of methoxyl. These results show that the most appropriate conditions for adequate extraction of lignin for application in resins are: 95% (w/w) of acetic acid, addition of 0.1% of HCl, temperature of 187 ÂC and reaction time of 15 min. The acetosolv lignins showed p-hidroxifenila units as major constituent, higher thermal stability and higher purity than the commercial Kraft lignin. The glass transition temperature of the Kraft lignins was lower than that of the acetosolv lignin. This is due to the hydrophilic character and the presence of carbohydrates in the Kraft lignin. The lignosulfonates obtained in this study showed structural characteristics suitable for application in phenolic resins, because they showed high reactivity due to the greater presence of p-hidroxifenila units as major constituent, low molecular weights (40234878 g/mol), greater stability and greater purity compared to commercial sodium lignosulfonate. Therefore, lignosulfonates obtained in this work are more suitable for use in phenolic resins than commercial sodium lignosulfonate used for comparison.
O presente trabalho teve por objetivo a produÃÃo de lignossulfonato, a partir da lignina extraÃda do bagaÃo da cana-de-aÃÃcar para aplicaÃÃo em resinas fenÃlicas. Foi realizada a otimizaÃÃo da extraÃÃo da lignina do bagaÃo de cana-de-aÃÃcar utilizando o processo acetosolv. Para tanto, empregou-se um delineamento composto central 22 para analisar os efeitos do tempo de reaÃÃo e da temperatura no rendimento de extraÃÃo, massa molar ponderal mÃdia, massa molar numÃrica mÃdia, e conteÃdo relativo de hidroxilas totais, hidroxilas fenÃlicas e metoxilas. As ligninas obtidas nas condiÃÃes que maximizaram o rendimento de extraÃÃo e que mostraram melhores caracterÃsticas estruturais e tÃrmicas foram sulfonadas para obtenÃÃo dos lignossulfonatos. As caracterÃsticas estruturais e tÃrmicas das ligninas e dos lignossulfonatos foram determinadas por FT-IR, GPC, RMN-1H e 13C, TGA e DSC. Os resultados mostram que o melhor rendimento de extraÃÃo (64,5 % 4,2%) foi obtido com 95% (m/m) de Ãcido acÃtico, adiÃÃo de 0,1% de HCl, a uma temperatura de 187 C e tempo de reaÃÃo de 40 min. No entanto, com a mesma concentraÃÃo de soluÃÃo de Ãcido acÃtico e com tempo de reaÃÃo de 15 min a 187ÂC, o rendimento de extraÃÃo diminuiu para 55,6%  4,5%, nÃo sendo significativa esta reduÃÃo. AlÃm disto, a elevaÃÃo da temperatura de 187ÂC para 205ÂC nÃo foi suficiente para causar um aumento significativo no conteÃdo relativo de hidroxilas e reduÃÃo do conteÃdo relativo de metoxila. Esses resultados mostram que as condiÃÃes mais adequadas para extraÃÃo da lignina a ser aplicada em resinas sÃo: 95% (m/m) de Ãcido acÃtico, adiÃÃo de 0,1% de HCl, temperatura de 187 C e tempo de reaÃÃo de 15 min. As ligninas acetosolv apresentaram unidades p-hidroxifenila como constituinte majoritÃrio, maior estabilidade tÃrmica e maior pureza em relaÃÃo à lignina Kraft comercial. A temperatura de transiÃÃo vÃtrea da lignina Kraft foi menor do que à das ligninas acetosolv, devido à sua caracterÃstica hidrofÃlica e à presenÃa de carboidratos na lignina Kraft. Os lignossulfonatos obtidos no presente trabalho apresentaram caracterÃsticas estruturais adequadas para aplicaÃÃo em resinas fenÃlicas, pois mostraram alta reatividade devido a maior presenÃa de unidades p-hidroxifenila como constituinte majoritÃrio, baixas massas molares (4023 a 4878 g/mol), maior estabilidade e uma maior pureza em relaÃÃo ao lignossulfonato de sÃdio comercial. Portanto, os lignossulfonatos obtidos no presente trabalho sÃo mais adequados para aplicaÃÃo em resinas fenÃlicas do que o lignossulfonato de sÃdio comercial utilizado no presente trabalho.

Anaerobic bioreactor landfills are the landfills with an increased moisture content inorder to achieve a better biodegradation. Many Bioreactor landfills accept outside liquid wastes to achieve a higher moisture content . But the effect of these wastes on the degradation of landfill components is not known. In this study, the effect of sugar waste, surfactant waste and paint waste on the degradation of landfill components was investigated. Sugar waste, surfactant waste and paint wastes in different concentrations were added to the combination of paper, cardboard, office paper and plastic with a total moisture content of 70%. The samples were incubated, sampled and analytical parameters analyzed. Sugar waste having a COD of 250,000 mg/L in a concentration of even 5% of the total weight was found inhibitive due to a drop in pH and accumulation of volatile fatty acids. Reactors with surfactant concentrations ranging from 50 mg/L to 500 mg/L showed that a higher concentration of 500 mg/L or above may be inhibitive in nature and the inhibition increases with increase in the concentration of surfactant. However, paint waste with a concentration of even 7.5% highly inhibited the degradation in the reactors. This could possibly be because of some toxicity.
Master of Science

The Queensland University of Technology (QUT) allows the presentation of a thesis for the Degree of Doctor of Philosophy in the format of published or submitted papers, where such papers have been published, accepted or submitted during the period of candidature. This thesis is composed of Seven published/submitted papers and one poster presentation, of which five have been published and the other two are under review. This project is financially supported by the QUTPRA Grant. The twenty-first century started with the resurrection of lignocellulosic biomass as a potential substitute for petrochemicals. Petrochemicals, which enjoyed the sustainable economic growth during the past century, have begun to reach or have reached their peak. The world energy situation is complicated by political uncertainty and by the environmental impact associated with petrochemical import and usage. In particular, greenhouse gasses and toxic emissions produced by petrochemicals have been implicated as a significant cause of climate changes. Lignocellulosic biomass (e.g. sugarcane biomass and bagasse), which potentially enjoys a more abundant, widely distributed, and cost-effective resource base, can play an indispensible role in the paradigm transition from fossil-based to carbohydrate-based economy. Poly(3-hydroxybutyrate), PHB has attracted much commercial interest as a plastic and biodegradable material because some its physical properties are similar to those of polypropylene (PP), even though the two polymers have quite different chemical structures. PHB exhibits a high degree of crystallinity, has a high melting point of approximately 180°C, and most importantly, unlike PP, PHB is rapidly biodegradable. Two major factors which currently inhibit the widespread use of PHB are its high cost and poor mechanical properties. The production costs of PHB are significantly higher than for plastics produced from petrochemical resources (e.g. PP costs $US1 kg-1, whereas PHB costs $US8 kg-1), and its stiff and brittle nature makes processing difficult and impedes its ability to handle high impact. Lignin, together with cellulose and hemicellulose, are the three main components of every lignocellulosic biomass. It is a natural polymer occurring in the plant cell wall. Lignin, after cellulose, is the most abundant polymer in nature. It is extracted mainly as a by-product in the pulp and paper industry. Although, traditionally lignin is burnt in industry for energy, it has a lot of value-add properties. Lignin, which to date has not been exploited, is an amorphous polymer with hydrophobic behaviour. These make it a good candidate for blending with PHB and technically, blending can be a viable solution for price and reduction and enhance production properties. Theoretically, lignin and PHB affect the physiochemical properties of each other when they become miscible in a composite. A comprehensive study on structural, thermal, rheological and environmental properties of lignin/PHB blends together with neat lignin and PHB is the targeted scope of this thesis. An introduction to this research, including a description of the research problem, a literature review and an account of the research progress linking the research papers is presented in Chapter 1. In this research, lignin was obtained from bagasse through extraction with sodium hydroxide. A novel two-step pH precipitation procedure was used to recover soda lignin with the purity of 96.3 wt% from the black liquor (i.e. the spent sodium hydroxide solution). The precipitation process is presented in Chapter 2. A sequential solvent extraction process was used to fractionate the soda lignin into three fractions. These fractions, together with the soda lignin, were characterised to determine elemental composition, purity, carbohydrate content, molecular weight, and functional group content. The thermal properties of the lignins were also determined. The results are presented and discussed in Chapter 2. On the basis of the type and quantity of functional groups, attempts were made to identify potential applications for each of the individual lignins. As an addendum to the general section on the development of composite materials of lignin, which includes Chapters 1 and 2, studies on the kinetics of bagasse thermal degradation are presented in Appendix 1. The work showed that distinct stages of mass losses depend on residual sucrose. As the development of value-added products from lignin will improve the economics of cellulosic ethanol, a review on lignin applications, which included lignin/PHB composites, is presented in Appendix 2. Chapters 3, 4 and 5 are dedicated to investigations of the properties of soda lignin/PHB composites. Chapter 3 reports on the thermal stability and miscibility of the blends. Although the addition of soda lignin shifts the onset of PHB decomposition to lower temperatures, the lignin/PHB blends are thermally more stable over a wider temperature range. The results from the thermal study also indicated that blends containing up to 40 wt% soda lignin were miscible. The Tg data for these blends fitted nicely to the Gordon-Taylor and Kwei models. Fourier transform infrared spectroscopy (FT-IR) evaluation showed that the miscibility of the blends was because of specific hydrogen bonding (and similar interactions) between reactive phenolic hydroxyl groups of lignin and the carbonyl group of PHB. The thermophysical and rheological properties of soda lignin/PHB blends are presented in Chapter 4. In this chapter, the kinetics of thermal degradation of the blends is studied using thermogravimetric analysis (TGA). This preliminary investigation is limited to the processing temperature of blend manufacturing. Of significance in the study, is the drop in the apparent energy of activation, Ea from 112 kJmol-1 for pure PHB to half that value for blends. This means that the addition of lignin to PHB reduces the thermal stability of PHB, and that the comparative reduced weight loss observed in the TGA data is associated with the slower rate of lignin degradation in the composite. The Tg of PHB, as well as its melting temperature, melting enthalpy, crystallinity and melting point decrease with increase in lignin content. Results from the rheological investigation showed that at low lignin content (.30 wt%), lignin acts as a plasticiser for PHB, while at high lignin content it acts as a filler. Chapter 5 is dedicated to the environmental study of soda lignin/PHB blends. The biodegradability of lignin/PHB blends is compared to that of PHB using the standard soil burial test. To obtain acceptable biodegradation data, samples were buried for 12 months under controlled conditions. Gravimetric analysis, TGA, optical microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), FT-IR, and X-ray photoelectron spectroscopy (XPS) were used in the study. The results clearly demonstrated that lignin retards the biodegradation of PHB, and that the miscible blends were more resistant to degradation compared to the immiscible blends. To obtain an understanding between the structure of lignin and the properties of the blends, a methanol-soluble lignin, which contains 3× less phenolic hydroxyl group that its parent soda lignin used in preparing blends for the work reported in Chapters 3 and 4, was blended with PHB and the properties of the blends investigated. The results are reported in Chapter 6. At up to 40 wt% methanolsoluble lignin, the experimental data fitted the Gordon-Taylor and Kwei models, similar to the results obtained soda lignin-based blends. However, the values obtained for the interactive parameters for the methanol-soluble lignin blends were slightly lower than the blends obtained with soda lignin indicating weaker association between methanol-soluble lignin and PHB. FT-IR data confirmed that hydrogen bonding is the main interactive force between the reactive functional groups of lignin and the carbonyl group of PHB. In summary, the structural differences existing between the two lignins did not manifest itself in the properties of their blends.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
The vegetable fibers has great variation according to the environment in which they develop and usually consist of about 50% cellulose, lignin 20%, 28% hemicellulose and 2% ash and other compounds. Among these, lignin represents one of the main obstacles to the process of enzymatic hydrolysis. In the production of cellulosic ethanol, lignin hinders access of hydrolytic enzymes to fermentable carbohydrates. The objective of this work was to quantify the amount of fiber and lignin content in clones ad varieties of sugar cane, and study the interaction for the characteristics: fiber content, yield and lignin content. So, ten clones and varieties of sugar cane were evalueted in a randomized block with six replicates in three regions of Minas Gerais, respectively Oratorios (CECA), João Pinheiro (Distillery WD) and Pompeu (Distillery Agropeu). The lignin content evaluation was performed in six replicates, whereas the yield and fiber content in three. The plots consisted of four ridges of 5 metres, with spacing of 1.40 metres. Genotypes x environments were not significant for the lignin content. There was no significant difference from the average effect of lignin content, the clones and varieties in the study sites, by Scott-Knott test at 5%probability. Significant effect of genotypes and environments, as well as the genotypes x environments interaction for the fiber content. There was significanteffect of genotype, environment and cutting, as well as their interactions to yield.
As fibras vegetais possuem grande variação de acordo com o ambiente no qual se desenvolvem e usualmente são constituídas por aproximadamente 50% de celulose, 20% de lignina, 28% de hemicelulose e 2% de cinzas e outros compostos. Dentre estes, a lignina representa um dos principais entraves ao processo de hidrólise enzimática, pois dificulta o acesso das enzimas aos carboidratos fermentáveis, no processo de fabricação de etanol celulósico. O objetivo deste trabalho foi quantificar o teor de fibras e lignina em clones e variedades de cana-de-açúcar, bem como avaliar as interações para as características: teor de fibra, produtividade e teor de lignina. Para tal, dez clones e variedades foram avaliados em blocos casualizados, com seis repetições em três regiões do estado de Minas Gerais, respectivamente, Oratórios (CECA), João Pinheiro (Destilaria WD) e Pompéu (Destilaria Agropéu). A avaliação do teor de lignina foi realizada em seis repetições, enquanto a produtividade e o teor de fibras em três. As parcelas foram constituídas de 4 sulcos de 5 metros, com espaçamento entre linhas de 1,40 metros. A interação genótipos x ambientes é não significativa para o teor de lignina. Não houve diferença significativa do efeito de médias do teor de lignina, dos clones e variedades nos ambientes estudados, pelo teste de Scott-Knott a 5% de probabilidade. Houve efeito significativo de genótipos e de locais, bem como da interação genótipos x ambientes para o teor de fibra. Houve efeito de genótipo, ambiente e corte, bem como de suas interações para produtividade (TCH).

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Objetivou-se, mediante o presente estudo, avaliar a eficácia da aplicação foliar de boro (B) associado, ou não, aos maturadores etil-trinexapac, etefon e sulfometuron metil na pré colheita da cana-de-açúcar, as alterações fisiológicas e suas implicações na qualidade e produtividade de colmos. O presente projeto foi composto de três subprojetos, sendo o primeiro abordando o uso de B associado ao etil-trinexapac, o segundo ao etefon e o terceiro ao sulfometuron metil. Para cada subprojeto foram conduzidos 4 experimentos em início e 4 em final de safra (2 locais e 2 anos), totalizando 12 experimentos em início de safra e 12 em final de safra, ou seja, 24 experimentos. Nos experimentos em início de safra, foi utilizada a variedade de cana-de-açúcar RB855453 (maturação precoce) nos dois locais e em final de safra foi utilizada a variedade SP80-3280 (maturação tardia) no Grupo Raízen e a variedade RB867515 (maturação média-tardia) no Grupo Tereos. Os tratamentos foram constituídos da aplicação dos maturadores etil-trinexapac, etefon, sulfometuron metil e do controle (maturação natural), associados à aplicação de B foliar. As doses empregadas foram, respectivamente, 200 g i.a. ha-1 (0,8 L p.c. Moddus ha-1), 480 g i.a. ha-1 (0,66 L p.c. Ethrel ha-1), 0,15 g i.a. ha-1 (0,20 g p.c. Curavial ha-1) e para o B, a dose foi 0,18 kg ha-1 (1060 g ácido bórico ha-1). Foram avaliados os parâmetros bioquímicos, biométricos, tecnológicos e nutricionais. Concluiu-se que a deficiência de B limita o acúmulo de sacarose em início e final de safra; a aplicação de maturadores em início de safra, isoladamente ou em associação ao B, possibilitou antecipação no corte da matéria-prima em cerca de 15 dias e o B aplicado isoladamente foi ainda mais eficiente, antecipando a maturação em cerca de 18 dias; em final de ...
The aim, through this study, was to evaluate the effectiveness of foliar application of boron (B), associated or not to the ripeners trinexapac-ethyl, ethephon and sulfometuron methyl in pre harvest of sugarcane, the physiological changes and their implications on quality and stalk yield. This project was composed of three subprojects, the first evaluating the use of B associated with trinexapac-ethyl, the second to ethephon and the third to sulfometuron methyl. For each subproject 4 experiments were carried out at the early and at the late season (2 places and 2 years), so were 12 experiments at early season and 12 at late season, totaling 24 experiments. In the experiments at early season, was used the variety of sugarcane RB855453 (early ripening) in both locations and at late season was used the variety SP80-3280 (late ripening) in Raízen Group and variety RB867515 (middle-late season) in Tereos group. The treatments consisted in the application of the ripeners trinexapac-ethyl, ethephon, sulfometuron methyl and control (natural ripening) associated with the application of B. The doses used were, respectively, 200 g i.e. ha-1 (0,8 L c.p. Moddus ha-1), 480 g i.e. ha-1 (0,66 L c.p. Ethrel ha-1), 0,15 g i.e. ha-1 (0,20 g c.p. Curavial ha-1) and for B the dose was 0,18 kg ha-1 (1060 g boric acid ha-1). Biochemical, biometric, technological and nutritional parameters were evaluated. It was concluded that B deficiency in pre-harvest of sugarcane limits the accumulation of sucrose at early and at late season; at early season the ripeners applied alone or in association with B enabled anticipation in the raw material harvesting in about 15 days and B applied alone was even more efficient, anticipating in about 18 days; at late season the ripeners were effective in maintaining the high sucrose concentration longer than control treatment, as well as B applied alone or in association with ...

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro
Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica, Niterói, RJ.
Este trabalho teve como objetivo avaliar as condições atuais do impacto da cana-de-açúcar nos sedimentos superficiais do Sistema Lagunar Mundaú- Manguaba, estado de Alagoas, litoral nordeste do Brasil. Nas ultimas três décadas, aproximadamente metade das bacias de drenagem no entorno do sistema estiveram cobertas por lavouras de cana. A utilização de marcadores geoquímicos orgânicos na determinação da origem da matéria orgânica tem-se mostrado uma ferramenta importante na avaliação da magnitude da poluição de sistemas lagunares por atividades agrícolas. Análises da composição elementar do carbono e nitrogênio orgânico (razão C:N) e isotópica do carbono (d13C), associadas à determinação de carboidratos e ligninas foram realizadas em 30 amostras de sedimentos totais ao longo das duas lagunas, canais e principais rios, bem como nas frações fina e grossa dos sedimentos. Além disso, foram analisadas 8 amostras de solo, procurando abranger todos os estágios de plantio da cana. A distribuição dos compostos analisados evidenciou a compartimentação do sistema em setores distintos, sugerindo que ocorram diferentes padrões de produção, introdução e degradação de matéria orgânica em cada região. De uma maneira geral, os valores de C:N e d13C indicam a presença de material autóctone nas partes centrais das lagunas e nos canais, a influência de fontes terrestres nos rios e uma mistura entre os dois tipos de material nas saídas dos rios. Nas amostras de solo foram verificadas o sinal característico de plantas C4, como a cana, com d13C próximo a -15‰ e razão C:N de 16, em média. A baixa razão C:N dos solos pode ser resultado, principalmente, da introdução de fertilizantes nitrogenados. As razões carboidrato:carbono foram mais elevadas nos solos e rios, indicando a presença de material vegetal. Da mesma forma, as maiores concentrações de ligninas (?) foram encontradas nas desembocaduras dos rios, evidenciando o aporte de material terrestre nesses locais. A distribuição das razões dos grupos fenólicos (S/V e C/V) não se mostrou muito distinta entre as estações, mas na maioria das amostras apresentou valores elevados da razão C/V, indicando a contribuição de angiospermas não lenhosas, tais como a cana, na composição de ligninas. Foi verificada a evidência de contribuição alóctone nas partes medianas das lagunas, mas os altos valores da relação entre as formas ácida e aldeídica do grupo vanilina [(Ad/Al)v] identificam o estágio avançado da degradação desse material, mascarando sinais específicos da cana. A entrada de matéria orgânica nas lagunas contribui para o aumento da produtividade primária, fato evidenciado pelas maiores concentrações de carboidratos nas regiões centrais. De uma maneira geral, as frações finas apresentaram-se enriquecidas em carbono e carboidratos, enquanto que valores elevados de ligninas e C:N, associados a valores de d13C mais leves, indicam que a fração grossa dos rios e região montante das lagunas é constituída principalmente por fragmentos vegetais. Os rios Paraíba do Meio e Mundaú apresentaram maior participação de cana em seus sedimentos, com 44% e 39%, respectivamente, enquanto que o rio Sumaúma apresenta aproximadamente 15% de cana em sua estação após a usina. O material lixiviado das bacias de drenagem provavelmente já é introduzido nos rios bastante processado, devido ao constante revolvimento e manejo dos solos.
This work aims to evaluate the actual conditions of sugar cane impact on the superficial sediments of Mundaú-Manguaba Lagoon System, State of Alagoas, Northeastern Brazil. During the last three decades, almost half of catchments areas around the system have been covered by sugar cane crops. Organic geochemistry tracers are currently used for the determination of organic matter origin as important tools for the pollution evaluation in lagoon systems affected by agricultural activities. Organic carbon and nitrogen analysis (ratio C:N), carbon isotopic analysis and carbohydrates and lignins determination were performed among 30 samples of course and fine fractions from two lagoons, channels and main rivers. Eight soil samples were also analyzed in order to represent all sugar cane cultivation stages. The compounds distribution showed the system partition to distinct sectors suggesting that different patterns of organic matter production, introduction and degradation occur in each regions. Overall, C:N e d13C values indicate presence of autochthonous material along central parts of lagoons and channels, influence of terrigenous source in rivers and a mixture of both materials at rivers outlets. The characteristic signal of C4 plants like sugar cane, were found in soil samples: d13C near to -15‰ and C:N ratio average 16. Lower C:N ratios may result, mainly, from the introduction of nitrogen fertilizers. Carbohydrate:carbon ratios were higher in soil and rivers, which indicate the presence of vegetal fragments. In the same way, higher lignin (?) concentrations were found at rivers outlets, showing the input of terrigenous sources at these locations. The distribution of phenoic groups ratios (S/V e C/V) were not significantly distinct between samples, but most of them had high values of C/V ratio, which indicates the contribution of non-woody angiosperms to lignins composition. There is an evidence of alochthonous contribution at median sectors, but high values of the acid:aldehyde ratios of vanillyl group [(Ad/Al)v] able the identification of advanced degradation stage of this material, hiding the specific signature of sugar cane. The input of organic matter in the lagoons improves the primary production, as showed by higher concentrations of carbohydrates in central sectors. In general, fine fractions had higher carbon and carbohydrate content. Meanwhile, higher values of lignins and C:N associated with lighter values of d13C indicate that the course fraction from rivers and month lagoons sector is constituted mainly by vegetal fragments. Paraíba do Meio and Mundaú rivers sediments presented higher sugar cane content, with 44% and 39% respectively, while sugar cane content was close to 15% in the station close to the plant in Sumaúma River. The leaching material from the cachtment area already reaches the rivers in a highlyprocessed form due to the constant mixture and management of the soils.

A biomassa lignocelulósica é um dos principais recursos energéticos alternativos para lidar com os problemas de aquecimento global e depleção dos recursos de combustíveis fósseis. O bagaço de uva é um exemplo de biomassa lignocelulósica que é composta por celulose, hemicelulose, lignina e outros compostos (ceras, taninos, etc.).. Assim, a valorização integral da biomassa do bagaço de uva branca e vermelha foi realizada de forma a maximizar o seu valor económico, para a produção de bio-açúcares, lignina, compostos fenólicos e nanocelulose. O processo foi iniciado com o fracionamento dos extrativos por Soxlet no qual foi possível verificar que independentemente do processo de extração aplicado, a % de extrativos é consideravelmente maior em bagaço de uva branca do que em uva vermelha (ca. 20%). A remoção da lignina para aumentar a acessibilidade aos açúcares e digestibilidade foi realizada através de uma reação alcalina. As concentrações de lignina mais elevadas (ca. 50 %) foram obtidas utilizando 1 % NaOH durante 60 min. Posteriormente, de forma a obter açucares fermentáveis (bio-açúcares), foram testadas hidrólises ácida e enzimática (celluclast e β-glucosidase) no material deslignificado. A hidrólise com ácido sulfúrico a 3,5% permitiu obter uma concentração máxima de glicose (3,22 g/L), xilose (7,29 g/L) e arabinose (0,91 g/L). No entanto, as concentrações mais elevadas de açúcares foram obtidas por hidrólise enzimática do que por hidrólise ácida diluída, com valores de glicose com 6,06 g/L e xilose com 8,08 g/L. De forma, a validar a fermentabilidade dos açucares, estirpes de Pichia stipitis e Saccharomyces cerevisiae foram avaliadas, e caracterizadas quanto à produção de etanol em meios produzidos com açucares provenientes de ambas as hidrolises ácidas e enzimáticas. Pichia stipitis mostrou ser a estirpe de levedura com o melhor crescimento e produção de etanol nos meios de cultura preparados com os açucares derivados da hidrólise enzimática. Foram obtidos rendimentos de etanol de cerca de 0,22 g/L ao longo dos estudos de fermentação. Saccharomyces cerevisiae foi capaz de produzir etanol em ambos os tipos de meio produzidos com açúcares obtidos das hidrólises ácidas e enzimáticas, mas no geral o rendimento de etanol foi baixo ca. 0,14 g/L e 0,005 g/L respectivamente. Desta forma, foi possível concluir que a fermentação com os meios com açucares derivados da hidrolise enzimática e com a estirpe Pichia stipitis, foram as melhores condições encontradas para produzir etanol. Por fim, a parte cristalina da celulose que não sofreu hidrólise foi valorizada para produção de nanocelulose. Foi possível produzir nanocelulose com tamanhos de ca. 295nm e um potencial zeta de -37 mv. Pela primeira vez, a biomassa de bagaço de uva é reportada como uma fonte de nanocelulose, eventualmente potenciando o seu valor
Lignocellulosic biomass is one of the potential and key alternative energy resources to deal with the problems of global warming and depletion of fossil fuel resources. Grape stalk is an example of lignocellulosic biomass which is composed of cellulose, hemicellulose, lignin and other compounds (waxes, tannins, etc.). Thus, the integral recovery of the biomass of the white and red grape stalk was carried out in order to maximize its economic value for the production of bio sugars, lignin, phenolic compounds and nanocellulose. The process was started with the fractioning of the extractives by Soxhlet, in which it was possible to verify that, regardless of the extraction process applied, the% of extractives is considerably higher in white grape stalk than in red grape stalk (ca. 20 %). Removal of lignin to increase the accessibility to sugars and digestibility was performed by alkaline reaction. The highest lignin concentrations (ca. 50 %) were obtained using 1 % NaOH during 60 min. Subsequently, to obtain fermentable sugars (bio sugars), acid and enzymatic hydrolysis (celluclast and β-glucosidase) were tested in the delignified material. Hydrolysis with 3.5% sulfuric acid yielded a maximum concentration of glucose (3.22 g/L), xylose (7.29 g/L) and arabinose (0.91 g/L) during 60 min. However, higher concentrations of sugars were obtained by enzymatic hydrolysis than by dilute acid hydrolysis, with glucose values of 6.06 g/L and xylose with 8.08 g/L. In order to validate the fermentation of the sugars, strains of Pichia stipitis and Saccharomyces cerevisiae were evaluated, and characterized in the ethanol production in media produced with sugars from both acidic and enzymatic hydrolysis. Pichia stipitis showed to be the yeast strain with the best growth and ethanol production in the culture media prepared with sugar derived from enzymatic hydrolysis. Ethanol yields of about 0.22 g/L were obtained throughout the fermentation studies. Saccharomyces cerevisiae was able to produce ethanol from in both types of media produced with sugars from enzymatic and acid hydrolysis, but overall ethanol yields were lower ca. 0.14 g/L and 0.005 g/L respectively. In this way, it was possible to conclude that the fermentation with the media with sugars derived from enzymatic hydrolysis and with the strain Pichia stipitis were the best conditions found to produce ethanol. Finally, the crystalline part of the cellulose that did not undergo hydrolysis was valued to produce nanocellulose. It was possible to produce nanocellulose with sizes ca. 295 nm and zeta potential of -37 mv. For the first time, grape stalk biomass is reported as a source of nanocellulose, eventually boosting its value.

SOMMARIO Gli incendi interessano vaste aree di superficie terrestre, più di ogni altro fattore naturale di disturbo. Essi sono un fattore ecologico primario nella formazione e nell’evoluzione degli ecosistemi forestali. Gli incendi hanno un forte impatto sulla sostanza organica del suolo, sulla sua abbondanza ma anche sulla sua composizione, che può subire profonde alterazioni. Durante la combustione hanno luogo reazioni che portano alla neo-formazione di composti aromatici, più o meno condensati, ad elevata recalcitranza. Nonostante gli studi intrapresi da tempo sul tema, ad oggi rimangono molte incertezze sui cambiamenti indotti dagli incendi sulla quantità, composizione e recalcitranza della sostanza organica del suolo. Gli obbiettivi di questa ricerca sono stati: (i) attestare l’impatto, nel brevissimo periodo, che hanno due fuochi di differente intensità sulla composizione e la quantità della sostanza organica del suolo; (ii) valutare l’applicazione complementare di tecniche spettroscopiche e termiche nello studio dei cambiamenti indotti da un incendio sulla sostanza organica del suolo; (iii) stimare, sul lungo periodo, l’effetto che ha un’elevata frequenza degli incendi sulla composizione e la permanenza della sostanza organica del suolo. Le analisi svolte in questa tesi hanno prodotto diversi dati utili, contribuendo alla comprensione dell’impatto degli incendi sulla sostanza organica del suolo. Per questo studio sono stati selezionati diversi siti forestali che, recentemente o in passato, sono stati percorsi da uno o più incendi. I primi due siti studiati sono stati Orentano (Italia) e Mount Gordon (Australia). Questi due siti sono stati paragonati per mettere in risalto l’effetto di incendi di differente intensità sulla quantità e sulla composizione della sostanza organica del suolo. I risultati sono stati analizzati cercando di trovare un indice di facile utilizzo in grado di definire sinteticamente l’intensità dell’incendio percepita al livello del suolo e il grado di deterioramento di quest’ultimo. Lo studio dei principali componenti della lettiera, come gli zuccheri e la lignina, e la composizione della sostanza organica totale rilevata con analisi all’NMR, non hanno fornito alcun parametro utile a risalire al grado di intensità dell’incendio a cui il suolo è stato soggetto. A Roccastrada, Toscana, è stato analizzato un suolo bruciato utilizzando contemporaneamente tecniche termiche e spettroscopiche contraddistinte dall’essere rapide e relativamente economiche. In questo modo è stato possibile caratterizzare efficacemente alcuni importanti cambiamenti della composizione della sostanza organica del suolo indotti dal passaggio del fuoco. Il passaggio del fuoco ha comportato una significativa riduzione della frazione organica, meno resistente alla degradazione biochimica, ed un relativo arricchimento di quella più recalcitrante. In più, il passaggio del fuoco ha portato alla formazione di composti contenenti azoto re-arrangiati in strutture relativamente resistenti alla degradazione. Infine è stata analizzata una sequenza climatica/altitudinale di suoli sull’Etna per valutare l’effetto di lungo termine degli incendi sulla composizione e la stabilità della sostanza organica del suolo. Sull’Etna, alle altitudini meno elevate, dove la frequenza degli incendi è maggiore, il tempo di residenza della frazione stabile della sostanza organica, carbone compreso, si è rivelato minore che alle quote superiori, mentre è stato rilevato un accumulo della frazione meno resistente e più facilmente degradabile. Ciononostante, in alcuni casi il carbone (macroscopico) contribuiva significativamente allo stock di carbonio totale nell’intero profilo del suolo, con tempi di permanenza stimati, con la tecnica del radiocarbonio, fino a 1400-1500 anni. Quindi un’elevata frequenza degli incendi sembra avere un “potere ringiovanente” sulla sostanza organica, rimuovendo, dalla superficie dei suoli in maniera non selettiva, parte della frazione con elevati tempi di residenza e biologicamente più recalcitrante. SUMMARY Fire affects more land surfaces than any other natural disturbance. It is a major driving factor in forest ecosystems formation and evolution. It has a strong impact on soil organic matter, primarily by changing its abundance. Also, soil organic matter composition is substantially affected by fire. During the combustion, many reactions take place, leading to the formation of thermally-condensed aromatic compounds characterised by high recalcitrance. However, there are still many uncertainties and contrasting results dealing with fire-induced changes in soil organic matter abundance, composition and recalcitrance. The aims of this study were: (i) assessing the immediate impact of two wildfires of different severity on soil organic matter composition and abundance; (ii) evaluating the complementary application of thermal and spectroscopic techniques to assess fire-induced changes to soil organic matter; (iii) estimating the long-term effect of a high fire frequency on soil organic matter composition and stability. This investigation provided useful information and contributes to the understanding of the overall impact of fire on soil organic matter. To carry out this study, we selected some forest sites that have been affected by one or more recent or past wildfires. Two sites, Orentano (Italy) and Mount Gordon (Australia), were contrasted to highlight the effect of wildfires of different severity on soil organic matter abundance and composition. The results were further analysed to find a possible reliable index of fire severity in soil, eventually useful to define the damage degree of soil quality or charring degree of necromass. Biogeochemical parameters, such as soil sugar and lignin contents and composition, as well as the black carbon spectroscopic properties, did not result useful for this purpose. At Roccastrada, Tuscany, Italy, the soil of a burnt pine forest was investigated by using a set of thermal and spectroscopic – rapid and cheap – techniques, that efficaciously characterised some important fire-induced changes in soil organic matter composition. They provided indications also on the burning temperatures occurred in soil. Fire produced a substantial reduction in the most labile organic fraction and a relative enrichment in recalcitrant organic matter. Additionally, the fire led to the formation of nitrogen-bearing compounds characterised by a fairly resistant structure. A topo-climosequence on Mt. Etna was finally analysed for estimating the long-term effect of wildfires on soil organic matter composition and stability. The residence time of the stable soil organic matter fraction – charcoal included – decreased from high to lower elevations, where fire frequency is higher. At lower elevations, labile organic matter, more easily degradable, accumulated in the mineral soil. Macroscopic charcoal fragments were present in significant amounts in the soil profile, showing radiocarbon ages up to 1400-1500 years. High fire frequency resulted to act as a powerful rejuvenating factor to soil organic matter, removing part of the very old, biologically recalcitrant organic matter from the surface horizons.

Fungus-derived glucose dehydrogenases (GDHs) are FAD-dependent enzymes belonging to the glucose-methanol-choline (GMC) oxidoreductase superfamily. GDHs are the most popular enzymes used in glucose sensor strips manufactured for glycemic control by diabetic patients. These enzymes are classified in the “Auxiliary activities” of the Carbohydrate-Active Enzymes (CAZy) database, since they act together with laccases in the process of lignocellulose degradation. Among fungi, the Basidiomycota Pycnoporus cinnabarinus is able to completely degrade lignin. We solved the crystal structure of GDH from P. cinnabarinus in the ligand-free form and in complex with glucose. The glucose-bound structure revealed two glucose molecules in close proximity to the FAD cofactor. Their orientation guided us to investigate the activity of the enzyme towards the disaccharide laminaribiose. Structural data on the laminaribiose-bound GDH showed a well-defined orientation of the disaccharide in the active site. Remarkably, the functional analysis revealed that the preferential substrate of this enzyme is indeed laminaribiose, with a 90% higher activity compared to glucose. Since beta-1,3 glucans are products of lignocellulose degradation, our structure-function analysis is consistent with the hypothesis of a fine tuning of the gene regulation and expression to adapt fungal organisms to the diversity of their natural substrates.