Typescript. Includes vita and abstract. Includes bibliographical references (leaves 110-120). Also available online in Scholars' Bank.

Thesis (doctoral)--Ludwig-Maximilians-Universität München, 2005. / Title from PDF title page (viewed on May 10, 2006). Includes articles written with other authors. In abstract, "b̳g̳" in "Kb̳g̳" appears as subscript. Includes bibliographical references.

Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (p. 108-112). Also available via the World Wide Web.

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Made available in DSpace on 2014-08-13T14:50:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-10-15Bitstream added on 2014-08-13T18:01:29Z : No. of bitstreams: 1 000747128_20150101.pdf: 686807 bytes, checksum: 2278e4a68ffc2a3a2e05e2b439aa4abb (MD5) Bitstreams deleted on 2015-01-05T11:00:51Z: 000747128_20150101.pdf,Bitstream added on 2015-01-05T11:01:48Z : No. of bitstreams: 1 000747128.pdf: 1781712 bytes, checksum: 14ce71d762a0054f37d5707681893a36 (MD5) / Os ácidos urônicos, D-galacturônico e D-glucurônico são encontrados em materiais lignocelulósicos e podem ser utilizados na indústria de alimentos e química. Estão presentes na estrutura fibrosa do bagaço de cana-de-açúcar e não são oxidados eletroquimicamente em eletrodos de carbono vítreo. Para isto foi desenvolvido um detector modificado com nanopartículas de cobre através da eletrodeposição potenciostática. Os ácidos D-galacturônico e D-glucurônico se oxidam de modo irreversível em potenciais de 0,45 e 0,48 V vs Ag/AgCl, respectivamente em voltametria cíclica. Outras técnicas voltamétricas tais como voltametria de pulso diferencial e voltametria de onda quadrada também foram estuda e o limite de deteção foi na ordem de 10-5 mol L-1 e a sensibilidade amperométrica na ordem de 104 μA mol L-1. O eletrodo desenvolvido foi utilizado em cromatografia com detecção amperométrica pulsada em célula wall-jet. Uma coluna de troca aniônica Carbo Pac Pa10 foi utilizada para separação dos ácidos urônicos em condições isocráticas, em fase móvel contendo 0,1 mol L-1 de NaOH com 0,280 mol L-1 de CH3COO-Na+ , potencial de detecção de 0,45 V vs Pd e fluxo de 1,0 mL min-1. A separação dos ácidos foi realizada em menos de 15 min. O limite de deteção ficou entre 5,8x10-7 e 7,3x10-7 mol L-1 e a sensibilidade amperométrica foi de 3,6±1,8 x106 μA mol L-1 e de 1,9±1,0x106 μA mol L-1 para os ácidos D-galacturônico e D-glucurônicos, respectivamente. O método foi aplicado em amostras reais de bagaço de cana-de-açúcar hidrolisado e a quantidade encontrada nesta amostra foi de 15,8±0,5 g/kg de ácido D-galacturônico e 12,5±0,5 g/kg para o ácido D-glucurônico. Os resultados demonstram que o método proposto pode ser utilizado para a detecção desses ácidos sem a necessidade de derivatização com as vantagens de ter menos interferentes, mantendo adequadas precisão e exatidão. / Uronic acid, D-glucuronic acid and D-galacturonic are found in lignocellulosic materials and can be used in the food industry and chemical industry. They are present in the fibrous structure of the sugarcane bagasse and are not oxidized at glassy carbon electrodes. For this we developed a detector modified with copper nanoparticles by potentiostatic electrodeposition. D-galacturonic acid and D-glucuronic irreversibly oxidize at potentials of 0.45 and 0.48 V vs. Ag/AgCl, respectively in cyclic voltammetry. Other voltammetric techniques such as differential pulse voltammetry and square wave voltammetry were also studied and the detection limit was in the order of 10-5 mol L-1 and amperometric sensitivity in the order of 10-4 mol L-1. The developed electrode was used in chromatography with pulsed amperometric detection in wall-jet cell. An anion exchange column, Carbo Pac PA10, was used for separation of uronic acids in isocratic conditions, mobile phase containing 0.1 mol L-1 NaOH and 0.28 mol L-1 CH3COO-Na+, the detection potential of 0.45 V vs. Pd and flow rate of 1.0 mL min-1. The separation of the acids was complete within 15 min. The detection limit was between 5.8x10-7 and 7.3x10-7 mol L-1, the amperometric sensitivity was 3.6 ± 1.8x106 and 1.9 ±1,0 x 106 mol L-1 to D-galacturonic acid and D-glucuronic, respectively. The method was applied to real samples of 300 mg of hydrolyzate bagasse. The value found in this sample was 15.8±0.5 g/kg of D-galacturonic acid and 12.5±0.5 g/kg to D-glucuronic acid. The results demonstrate that the proposed method can be used to detect these acids without the need for derivatization with the advantage of having fewer interfering, considerable accuracy.

Orientador: Alessandro de Mello Varani / Coorientador: Lucia Maria Carareto Alves / Banca: Victor Satler Pylro / Banca: Jackson Antonio Marcondes de Souza / Resumo: A indústria sucroalcooleira gera elevado número de resíduos de origem da biomassa lignocelulósica que apresentam grande potencial para produção de biocombustíveis, em particular o etanol de segunda geração. Uma das formas promissoras para a desconstrução da biomassa lignocelulósica é através da utilização de consórcios bacterianos que produzem enzimas altamente específicas com a capacidade de quebrar a estrutura da lignocelulose. Porém, para a otimização desse processo é importante entender as funções metabólicas presentes nesses consórcios degradadores de biomassa. Portanto, esse estudo objetivou identificar e classificar a composição de uma comunidade bacteriana proveniente de consórcio oriundo de solo contendo bagaço de cana-de-açúcar em decomposição e avaliar sua capacidade metabólica através de sequenciamento genômico de alto rendimento e análises de bioinformática. Esse consórcio foi cultivado durante vinte semanas, sendo que amostras de DNA foram extraídas para sequenciamento a cada sete dias. O sequenciamento da subunidade 16S do operon ribossomal (16S rRNA) foi realizado utilizando a plataforma Ion PGM™, enquanto que o sequenciamento do DNA total foi realizado na plataforma HiSeq 2500, Illumina®. Os resultados do sequenciamento do 16S rRNA indicam 5 diferentes famílias bacterianas ao longo das 20 semanas, sendo Burkholderiaceae (73%) e Rhodanobacteraceae (24%) as mais abundantes. Análises do potencial funcional do consórcio realizadas através dos programas PICRUSt e ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The sugarcane ethanol industry generates a number of residues related to the lignocellulosic biomass which exhibit potential for the production of biofuels, in particular second generation ethanol. One of the promising ways for the deconstruction of lignocellulosic biomass to valuable products is through the use of bacterial consortia. These consortia encode a specific set of enzymes capable to metabolize and decompose the lignocellulose structure. However, to optimize this process, the metabolic functions present in a biomass-degrading consortia must be well known. Therefore, this study aimed to unravel the taxonomic composition, and to evaluate the metabolic profile of a bacterial consortium from a sugar-cane derived soil containing decomposing straw, through high-throughput genomic sequencing and bioinformatics analyzes. The selected consortium was cultivated in laboratory for twenty weeks, and DNA samples were extracted for sequencing every seven days. The 16S subunit of the ribosomal operon (16S rRNA) and total DNA sequencing were performed through the Ion PGM™ (Thermo Fischer) and HiSeq 2500 (Illumina) platforms, respectively. The 16S rRNA sequencing indicate at least 5 different bacterial families during the 20 weeks of cultivation. The Burkholderiaceae (73%) and Rhodanobacteraceae (24%) are the most abundant. Functional analyses, indicate an enrichment of the transporter-related function, including ABC-transporters mainly in the first week of cultivation, suggesting a probable role related with the decomposing of the lignocellulolytic material. The whole metagenome sequencing uncover the genomic sequence of one of the most abundant organisms present in the consortium (abundance ~24% of the sequenced reads). This genome was finished and circularized, exhibiting 4,758,639 bp, GC% of 65.25, a... (Complete abstract click electronic access below) / Mestre

Orientador: Clóvis Augusto Ribeiro / Banca: Arnaldo Sarti / Banca: José Fernando de Andrade / Resumo: O Brasil é um país rico em diversas biomassas, como resíduo de cana de açúcar, bagaço de laranja, entre outros. Uma fonte de biomassa são os resíduos de poda de árvores, o qual toda cidade possui. Para garantir a saúde pública, o tratamento de água para o abastecimento de uma cidade é fundamental. Nas ETAs, estações de tratamento de água, o processo de tratamento gera um resíduo, o lodo, cuja destinação é precária e muitas vezes inadequada. De acordo com a Lei Federal Brasileira No 12.305/2010, Política Nacional de Resíduos Sólidos, deve haver aproveitamento de resíduos de forma economicamente viável e ambientalmente correta dos resíduos sólidos e disposição apropriada quando não possível tal aproveitamento. Assim, o objetivo deste trabalho foi produzir um biocarvão da união destes dois resíduos, de forma a propor possível substituição do carvão antracitoso, utilizados nas ETAs. Desta forma foram coletadas amostras de serragem de poda de árvores e lodo de ETA. Estes materiais foram com- binados (blendas) nas proporções 10 % a 80 % em massa de lodo (LD) por massa de poda (BM) e submetidos à pirólise sob baixa temperatura (torrefação)(260 ◦C). Todas as amostras foram submetidas à análise termogravimétrica e através da estabilidade térmica em meio aquoso, e peletização, o biocarvão BB20 (20% de LD e 80% de BM) apresentou os melhores resultados e foi selecionado dentre as misturas. Foram efetua- das caracterizações por AI, FTIR, densidade, MEV, EDS, análise elementar, isotermas d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is a country rich in several biomasses, such as sugarcane residue, orange bagasse, among others. A source of biomass is pruning waste of trees, which every city has. To ensure public health, the water treatment for supplying a city is crucial. In the WTPs, water treatment plants, the treatment process generates a residue, the sludge, whose destination is precarious and often inadequate. According to the Brazilian Federal law number 2010/12.305, National Solid Waste Policy, should use of waste in an economically viable and environmentally sound way of solid waste and appropriate disposal where such use is not possible. Thus, the objective of this work was to produce a biochar of the union of these two residues, in order to propose possible substitution of the anthracyte coal, used in the WTPs. In this way, samples of sawing of trees pruning and WTP sludge was collected. These materials were combined (blends) in the proportions 10% to 80% by mass of sludge (LD) per mass of pruning sawdust (BM) and subjected to pyrolysis at low temperature (torrefaction) (260 C). All samples were submitted to thermogravimetric analysis and thermal stability in aqueous medium, and pelletizing, BB20 (20% of LD and 80% BM) showed the best results and was selected of the blends. Characterizations were performed by AI, FTIR, density, SEM, EDS, elemental analysis, nitrogen adsorption isotherms, porosity by mercury intrusion and adsorption tests with methylene blue. The density was of 0.3 g cm−... (Complete abstract click electronic access below) / Mestre

A busca por segurança energética tem feito com que a maioria dos países empenhe-se na busca por fontes alternativas de energia, procurando mitigar problemas econômicos, sociais e ambientais. Espera-se que a biomassa, disponível de forma geograficamente dispersa, venha a tornar-se um dos principais recursos renováveis na produção de alimentos, materiais, produtos químicos, combustíveis e energia. Nesse cenário, o desenvolvimento de biorrefinarias representa a chave para uma produção integrada, combinando rotas de conversões químicas, bioquímicas e termoquímicas, no processamento da biomassa, visando à utilização otimizada dos recursos disponíveis. As biorrefinarias com estruturas descentralizadas são uma alternativa à centralização de produções em grandes plantas industriais e à monocultura, pois utilizam biomassas disponíveis regionalmente, integram sistemas de produção, potencializando os recursos locais, reduzem custos com logística e impactos ambientais, além de melhorarem a distribuição da renda. O presente trabalho apresenta uma revisão da disponibilidade de biomassa no Brasil e no mundo, com especial interesse no aproveitamento de microalgas e resíduos orgânicos, dos principais produtos de interesse e conceitos de biorrefinarias existentes. O objetivo é discutir qual é o conceito que melhor se adapta às necessidades do cenário brasileiro, bem como propor um modelo com estrutura descentralizada em duas ou três etapas, visando à otimização de um processamento sustentável de biomassa para obtenção de vários produtos comerciáveis e energia, além de delinear diretrizes para investimentos na área. É apresentada uma metodologia para a tomada de decisões na concepção e análise de viabilidade do projeto conceitual de uma biorrefinaria, considerando-se também as restrições de ordem ecológica, econômica e tecnológica. Como estudo de caso, é proposta uma biorrefinaria a partir de microalgas. A escolha por microalgas como matéria-prima é baseada nas vantagens que sua utilização apresenta frente à de outras biomassas, dentre elas cita-se a capacidade de produção rápida e durante todo o ano, a captura do CO2 necessário ao seu crescimento, a necessidade de menos água do que plantas terrestres, são cultiváveis em água salobra e terras não aráveis, apresentam elevado teor de óleo, seus nutrientes podem ser obtidos a partir de águas residuais, sua composição bioquímica pode ser modulada por diferentes condições de crescimento e são capazes de produção fotobiológica de bio-hidrogênio. Das alternativas de rotas possíveis para seu processamento, são apresentadas duas que apontam como sendo as mais promissoras: o uso da microalga como substrato de algum outro microorganismo, visando à obtenção de compostos com maior valor agregado, tais como biopolímeros, e o uso do processo de pirólise rápida para obtenção de bio-óleo, que deve ser processado posteriormente, visando à especificação em biocombustível. As vantagens da otimização do cultivo, colheita, rotas viáveis de processamento e a análise do potencial econômico desse modelo, indicam uma excelente oportunidade para obtenção de um espectro de produtos de alto valor agregado e energia e um grande potencial de aplicação. / The search for energy security has been doing with that most of the countries strive to seek alternative sources of energy that allows mitigating economic, social and environmental problems. It is expected that biomass, available on a geographically dispersed way, will become one of the major renewable resources for food, materials, chemicals, fuels and energy production. Additionally, the development of biorefineries represents the key to an integrated production, combining chemical, biochemical and thermochemical conversion routes for biomass processing, aiming the optimized use of available resources. Biorefineries with decentralized structure are an alternative to the centralization of production in large industrial plants and to the monoculture because it uses biomass regionally available, integrates production systems potentiating local resources, reduces logistics costs and environmental impacts, as well as improves income distribution. This work presents a review of: i) biomass availability in Brazil and in the world, focus on the use of microalgae and organic wastes; ii) the main products of interest; and; iii) concepts of existing biorefineries. The objective is to discuss which one is the concept that better fits the needs of the Brazilian scenario and propose a new model with decentralized structure in two or three stages, seeking to an optimized and sustainable biomass processing to obtain various marketable products and energy, and delineate guidelines for investment in the area. It is presented a methodology for making the conceptions decisions and feasibility analysis of the conceptual design of a generic refinery, considering also the ecological, economic and technological constraints. As a case study, it is proposed a biorefinery from microalgae. The choice of microalgae as a raw material is based on the advantages that their use offers over the others biomasses. Among the advantages it can be cited the ability for rapid production and during all the year, the capture of CO2 for its growth, the need for less water than land plants, they can be cultivated in brackish water and non-arable land, have a high oil content, nutrients can be obtained from waste water, their biochemical composition can be modulated by different growth conditions and are capable of producing photobiology bio-hydrogen. Of the possible alternative routes for microalgae processing, are presented two as the most promising: the use of microalgae as a substrate for some other microorganism in order to obtain compounds with high added value, biopolymers as an example, and use the process of fast pyrolysis for obtaining bio-oil, which will be processed later in order to specify biofuels. The advantages of the cultivation optimization, harvesting, processing viable routes and analyzing the economic potential of this model indicate an excellent opportunity to obtain a spectrum of value-added products and energy and its great potential for application.

Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.

The growth and physiology of <i>Saccharomyces cerevisiae</i> GB4918 (baker’s yeast) was studied under glucose-limitation in chemostat culture. Levels of lg/1 (0.1% w /v) glucose allowed cell growth while preventing fermentation in a defined medium (QEMM3). Metabolism of glucose by respiration or fermentation was shown to affect the mean cell volume, with fermentative use of glucose causing an increase in cell size. This was also a major physiological difference between <i>S. cerevisiae </i>GB4918 (a Crabtree positive yeast) and <i>Kliiyveromyces marxianus</i> DBVPG 6165 (a Crabtree negative yeast). The ability of the Crabtree positive yeast to substantially increase its mean cell volume was also reflected in a 5-fold greater consumption of glucose, reduced biomass yield and increased ethanol yield, compared with the Crabtree negative <i>K . marxianus</i>. Growth of both these yeasts was seen in 50g/l glucose in the presence of the respiratory inhibitor, antimycin A. This was evident by the switching to fermentation in <i>K . marxianus</i>, and the complete fermentation of glucose by <i>S. cerevisiae</i>. The growth and physiology of <i>S. cerevisiae</i> GB4918 was also established in glucose-limited chemostat cultures, with special regard to the intracellular macromolecular compounds that are relevant to industrial yeast biomass production. This showed that in respiring cultures of <i>S. cerevisiae</i>, increasing growth rate resulted in decrease in both trehalose and glycogen content, while increasing protein and RNA. This is true until μ_max (in this context the growth rate at which respiro-fermentativemetabolism occurs) when accumulation of trehalose and glycogen is apparent. Once μ_erit (growth rate at which washout of the culture begins) was reached then biomass significantly reduced. In describing the steady-state condition of baker’s yeast it was then possible to describe changes occurring in yeast when subjected to a variety of nutrient perturbations. With a lactic acid (2% v/v) perturbation there were dramatic effects on both growth and metabolism at a growth rate of 0.12h_1, but significant decreases in biomass and protein, and significant increases in trehalose and glycogen. At a higher growth rate (0.22h_1) the effect was much severer on protein content, and on reduced levels of trehalose and glycogen. The effect of perturbing the cultures with elevated levels of calcium was also most significant on reducing yeast trehalose and glycogen levels, probably due to inhibition of the biosynthesis of these compounds. Zinc additions to chemostat cultures acted to increase the levels of protein in the cells,while having little effect on any of the other cellular macromolecules. This suggests that increasing calcium levels during the latter stages of yeast propagations may produce a yeast with reduced stress responses. Increased zinc may also encourage a greater protein content, which would, in turn, provide a better nutritive content for both protein and amino acids in yeasts destined for use as a food additive.