O crescimento do potencial energético a partir da biomassa estimula o desenvolvimento e a criação de novas tecnologias neste setor. Neste trabalho realizou-se uma ampla pesquisa da produção, compressão e acondicionamento do biogás. Constatou-se durante essa pesquisa a necessidade da busca por alternativas que possibilitem a utilização eficiente deste biocombustível. Analisou-se a possibilidade da fabricação de um compressor alternativo para biogás que possa ser aplicado em pequenas unidades de produção por meio da modelagem das partes componentes. Primeiro efetuou-se a escolha do material considerando-se as características adequadas para construção do sistema de compressão. Depois disto dimensionou-se a camisa de compressão e a sua modelagem tridimensional com software Inventor 2010 (versão Student), além de válvulas e matrizes para fabricação. Complementarmente foi simulado o funcionamento do compressor (gráfico do deslocamento, velocidade e força com o software FluidSim da Festo Didatic). Por último executou-se o projeto eletropneumático, energização e lista de dispositivos necessários para montagem do compressor. Observou-se que essa tecnologia pode ser aplicada em pequenas plantas de produção de biogás. A comparação com outros sistemas de compressão revelou vantagens como a não haver contaminantes na compressão e acionamento, além da compressão poder se dar em ambiente separado do seu acionamento. / The growth of the energy potential from the biomass stimulates development and creation of new technologies in this sector. In this work is carried out extensive research in production, compression and biogas bottling. The need to search for alternatives has been evidenced during the research to make possible the efficient use of biofuel. After it analyzed the possibility of manufacturing of an alternative compressor for biogas which can be applied in small production units through the modeling of the contracting parties. At first it was effected the material choice considering the characteristics for the construction of the compression system. After this, was dimensioned a compression jacket, valves and matrices with the Student software Inventor 2010. Moreover the functioning of the compressor was simulated (its graphical of the displacement, speed and force with a FluidSim software from Festo Didatic). Finally was made a pneumatic project and was executed a list of necessary devices for the compressor assembly. It was observed to that this technology can be applied in small plants of production of biogas. The comparison with other systems of compression demonstrates that tis compressor haven’t contaminants, beyond the compression to be able to give itself in separate environment of its drive.

Microrganismos simbiontes são essenciais para a exploração de dietas de baixo valor nutricional, o desenvolvimento, crescimento e a reprodução de seus hospedeiros. Insetos que se alimentam de dieta rica em materiais celulósicos, como é o caso de cupins, apresentam protozoários e/ou bactérias associadas ao trato digestivo que auxiliam na quebra do polímero de celulose e na fixação de nitrogênio. A celulose e a hemicelulose são polímeros estruturais formados por unidades de glicose, sendo a hidrólise desses polímeros de grande interesse industrial para a produção de etanol. O modo mais eficiente de hidrolisar a celulose é pelo uso de enzimas, as celulases. Os cupins apresentam grande eficiência na digestão de celulose e hemicelulose, sendo que a compreensão do processo de digestão de celulose por esses insetos pode facilitar o desenvolvimento de tecnologia mais eficiente para a quebra desse polímero. Assim, este trabalho buscou i) isolar, identificar e caracterizar microrganismos associados ao trato digestivo dos cupins Armitermes euamignathus (Isoptera: Termitidae) e Coptotermes gestroi (Isoptera: Rhinotermitidae); ii) verificar o potencial da microbiota na degradação dos principais componentes da lignocelulose (celulose, xilana e pectina); iii) caracterizar o potencial hidrolítico e determinar as condições ótimas de hidrólise (pH e temperatura das diferentes enzimas produzidas). A análise da microbiota cultivável levou à identificação de 14 filotipos para A. euamignathus e de 11 para C. gestroi, distribuídos nos quatro principais filos, Proteobacteria, Firmicutes, Bacteroidetes e Actinobacteria. A caracterização da microbiota não-cultivável levou à identificação de 17 filotipos em operários e três em soldados de A. euamignathus, enquanto que em C. gestroi foi possível identificar seis filotipos em operários e oito em soldados. O filo Firmicutes foi o mais abundante em A. euamignathus, enquanto Proteobacteria predominou em C. gestroi. O isolamento de bactérias em meio seletivo para degradação de celulose, xilana ou pectina levou à seleção de oito filotipos para A. euamignathus e cinco para C. gestroi. Extratos brutos obtidos do cultivo dessas bactérias apresentaram atividade de hidrólise de pectina e xilana, mas não celulose. Ensaios para otimização das reações de degradação indicaram a presença de enzimas que atuam em diferentes faixas de pH ótimo. Assim, a microbiota associada aos cupins estudados foi bastante diversa, apresentando ainda diferenças entre as diferentes castas desses insetos. Essa microbiota também atua em parte do processo de degradação da celulose, demonstrando o potencial que bactérias associadas ao intestino de cupins podem apresentar para a identificação de enzimas digestivas que possam ser utilizadas no processamento da celulose. / Symbionts are essential for insect hosts as they enhance the nutritional value of their host diets and support host development, growth and reproduction. Insects that feed on diets rich in cellulose, such as termites, exhibit protozoa and/or bacteria within their digestive tract that aid in breaking the cellulose and in nitrogen fixation. Cellulose and hemicellulose are polymers formed by units of glucose, and the hydrolysis of these polymers is of great industrial interest for the production of ethanol. Cellulases are the most efficient enzymes to break cellulose. Termites have a huge capacity to digest cellulose and hemicellulose; thefore, understanding the process by which they digest cellulose may allow the development of more suitable technologies devoted to the industrial utilization of cellulose. This work aimed to i) isolate, identify and characterize microorganisms associated with the digestive tract of Armitermes euamignathus (Isoptera: Termitidae) and Coptotermes gestroi (Isoptera: Rhinotermitidae), ii) investigate the potential of symbionts in the degradation of the main components of lignocellulose (cellulose, xylan and pectin); iii) characterize the hydrolytic potential and determine the optimum hydrolysis conditions (pH and temperature) for the different enzymes produced. The analysis of culturable microorganisms led to the identification of 14 phylotypes for A. euamignathus and 11 for C. gestroi, which were distributed in four Phyla, Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. The characterization of the non-culturable microbiota led to the identification of 17 phylotypes in workers and three in soldiers of A. euamignathus, while six phylotypes were identified in workers and eight in soldiers of C. gestroi. Firmicutes was the most abundant in A. euamignathus, while Proteobacteria predominated in C. gestroi. The isolation of bacteria in selective medium to degrade cellulose, xylan or pectin led to the selection of eight phylotypes from A. euamignathus and five from C. gestroi. Crude extracts obtained from the cultivation of these bacteria showed hydrolytic activity towards to xylan and pectin, but not cellulose. Assays for optimization of enzymatic reaction indicated the presence of enzymes that act at different pH ranges great. As a conclusion, symbiont diversity was quite different between the termites species and in between the castes of these species. But the microbiota isolated also acts in the degradation of cellulose, demonstrating the potential for the gut-associated bacteria of termites may present for the identification of digestive enzymes which can be used in the processing of cellulose.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-03-08T18:02:48Z No. of bitstreams: 2 Gabriela_Bonassa2017.pdf: 2330035 bytes, checksum: 2e5835687d6a7fb1deae6e756eb079b8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-08T18:02:48Z (GMT). No. of bitstreams: 2 Gabriela_Bonassa2017.pdf: 2330035 bytes, checksum: 2e5835687d6a7fb1deae6e756eb079b8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The sugarcane bagasse fly ash are byproducts generated in the sugar and alcohol industry in energy cogeneration, and due to their alkaline characteristics, abrasive and porous, present great potential to be used as an adsorbent material, such as in cooking oil purification. These residual oil are derived from the process of cooking food, presenting itself as an environmental, economic and social alternative for use as a feedstock for biodiesel production. By considering the high temperatures and multiples utilizations of these oils, which are put into contact with diversified and frozen foods, induce the minimization of their quality due to the high concentration of free fatty acids, moisture and peroxides arising from hydrolysis and oxidation reactions. In this sense, the aim of the present work was the evaluation of the adsorbent potential of sugarcane bagasse fly ash and activated carbon in the purification of waste cooking oil, evaluating operational conditions that may influence the adsorption process. Both materials were characterized by N2 Physisorption, Scanning Electron Microscopy and Dispersive Energy Spectroscopy, for textural, morphological and composition analyzes. In the waste cooking oil treatment step, temperatures rages from 15 to 25 ºC, adsorbent mass from 0,33 to 4,95 g and agitation speed between 50 and 200 rpm, the independent variables were predetermined in an experimental planning of the Rotational Central Composite Design, which aims to optimize the process by reducing the number of tests. It was found statistically in the intervals studied that the different conditions were statistically significant in the reduction of acidity (AV) and peroxide (PV) values and both materials provided near efficiencies in the improvement of residual oil quality, wherein the ashes led to a AV and PV minimizations around 59 and 25 %, respectively, while by using the commercial adsorbent (activated carbon), 57 and 27 %. The utilization of bagasse fly ashes in the waste cooking oil treatment, due to their low cost and be a waste generated in large quantities in Brazil provide positive advantages from the environmental, economic and social point of view. In addition, considering its efficiency to such application which is comparable to the commercial adsorbents, they minimize the expenses relates to the feedstock purification stages for biodiesel synthesis, from residual oils with high levels of oxidation and free fatty acids. / As cinzas de bagaço de cana são subprodutos gerados na indústria sucroalcooleira na cogeração de energia, e devido as suas características alcalinas, abrasivas e porosas, possuem potencial de serem aplicadas como material adsorvente, na purificação de óleo residual. Este é proveniente do processo de cocção de alimentos, apresentando-se como alternativa do ponto de vista ambiental, econômico e social para emprego como matéria-prima na produção de biodiesel. No entanto, as altas temperaturas e múltiplas utilizações do óleo durante a fritura, além do contato com alimentos diversificados e congelados, induzem a minimização de sua qualidade devido à elevada concentração de ácidos graxos livres, umidade e peróxidos que este passa a possuir, provenientes das reações de hidrólise e oxidação. Nesse sentido, o objetivo do presente trabalho foi à avaliação do potencial adsorvente das cinzas de bagaço de cana e carvão ativado na purificação do óleo residual, em diferentes condições operacionais que influenciam no processo de adsorção. Ambos os materiais foram caracterizados por Fisissorção de N2, Microscopia Eletrônica de Varredura e Espectroscopia de Energia Dispersiva, para análises texturais, morfológicas e semi-elementares. Na etapa de tratamento do óleo residual, testaram-se faixas de temperatura de 15 a 25 ºC, massa de adsorvente de 0,33 a 4,95 g e agitações entre 50 a 200 rpm, variáveis independentes pré-determinadas em um planejamento experimental do tipo Delineamento Composto Central Rotacional, que visa a otimização do processo com a redução do número de ensaios. Constatou-se que estatisticamente os intervalos estudados são significativos na redução dos índices de acidez (IA) e peróxido (IP) e ambos os materiais proporcionaram eficiências próximas no aprimoramento da qualidade do óleo residual, com as cinzas as minimizações da concentração de IA e IP chegaram a 59 e 25 %, respectivamente, enquanto que empregando o adsorvente comercial (carvão ativado), 57 e 27 %. A utilização das cinzas de bagaço no tratamento de óleo residual, devido ao seu baixo custo e serem resíduos gerados em grandes quantidades no Brasil proporcionam vantagens positivas do ponto de vista ambiental, econômico e social. Além disso, por possuírem eficiência em tal aplicação comparável a adsorventes comerciais, minimizam os gastos atrelados às etapas de purificação de matérias-primas para síntese de biodiesel, a partir de óleos residuais com elevados teores de oxidação e ácidos graxos livres.

A presente dissertação visa compreender a relação das políticas públicas com o desenvolvimento do setor sucroenergético, tendo em vista as exigências da comunidade internacional em relação à produção de combustíveis sustentáveis sob a ótica do mercado globalizado. Partimos da análise das políticas públicas para agricultura, energia e meio ambiente e da política externa brasileira para os biocombustíveis nos governos Fernando Collor de Mello, Itamar Franco, Fernando Henrique Cardoso e Luís Inácio Lula da Silva. Após isso, analisamos as políticas públicas ambientais e de ordenamento territorial através da compreensão dos três zoneamentos existentes para o setor sucroenergético, com um recorte no estado de São Paulo. Finalmente, discutimos os acordos internacionais para o setor de biocombustíveis. / This work aims to understand the relationship between public policy and the development of sugarcane industry, in view of the international communitys regarding sustainable production of fuels from the perspective of the global market. First, we analyze the public policies for agriculture, energy and environment and foreign policy for biofuels in Brazilian government of Fernando Collor de Mello, Itamar Franco, Fernando Henrique Cardoso and Luís Inácio Lula da Silva. After that, we analyze the public policy for environmental and the land use planning, through the understanding of the three existing zoning for the sugarcane industry, with an indentation in the state of Sao Paulo. Finally, we discuss the international agreements for the biofuels sector.

Orientadores: Arnado Walter, Pita A. Verweij / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T18:29:44Z (GMT). No. of bitstreams: 1 Oliveira_CamilaOrtolanFernandesde_M.pdf: 2988972 bytes, checksum: f3c588b875a6de9627585059b114f30b (MD5) Previous issue date: 2013 / Resumo: A sustentabilidade dos biocombustíveis é uma questão polêmica, que ganhou grande dimensão desde a segunda metade da década passada. Nesse contexto, biodiversidade é um dos aspectos mais mencionados no debate internacional. Em função das pressões de diferentes segmentos sociais, critérios de sustentabilidade foram definidos e têm condicionado a aplicação de políticas de fomento aos biocombustíveis. Na prática, esquemas de certificação têm sido usados de forma crescente e nada indica que essa tendência seja alterada. Assim, a futura produção de etanol de cana de açúcar no Brasil, e a competitividade da produção nacional em mercados internacionais, estarão condicionadas a que sustentabilidade seja uma realidade, e possa ser comprovada. No Brasil, muito pouco se sabe sobre os impactos da produção de cana, e de etanol, sobre a biodiversidade, e foi isso que motivou esta dissertação. Seu objetivo geral é o entendimento da questão biocombustíveis-biodiversidade, incluindo a identificação do conhecimento existente, das diferentes visões, das aspirações, etc. A análise foi feita com foco na produção de etanol de cana, nas condições brasileiras, e de suas perspectivas. Um dos objetivos específicos foi definido na avaliação dos esquemas de certificação, e como neles a biodiversidade tem sido tratada. Uma das conclusões desta dissertação é que, não só no Brasil, ainda pouco se sabe sobre os impactos dos biocombustíveis sobre a biodiversidade. Segundo, biodiversidade é um tema complexo, que tem várias dimensões, e em um esquema de certificação não se pode ter as mesmas ambições de avaliação e monitoramento de trabalhos científicos. Mais ainda, esquemas de certificação são instrumentos de mercado, e precisam ser definidos tendo-se em mente aspectos condicionantes como a praticidade, os custos, e as responsabilidades que podem ser atribuídas ao agente econômico que é avaliado. Entretanto, em geral os esquemas de certificação de biocombustíveis são mais rigorosos do que os esquemas que tratam de produtos florestais e alimentícios, e estão alinhados com os indicadores recomendados para empresas de energia. De qualquer forma, mecanismos de certificação têm um importante papel a cumprir no fomento às iniciativas, na disseminação de informações e na diferenciação de produtores e produtos. As normas devem ser entendidas como complementares à regulação pública e, dessa forma, podem ser muito úteis. Finalmente, conclui-se que as leis e a regulação do uso da terra no Brasil (e.g., o Código Florestal, o Zoneamento Agroecológico e a definição de Áreas Prioritárias de Conservação) podem ser, desde que adequadamente aplicadas, suficientes para que os potenciais impactos sobre a biodiversidade sejam evitados ou minimizados. Com a legislação existente, e com a pressão do mercado e dos segmentos sociais, a produção de etanol de cana no Brasil tem amplas condições de ser cada vez mais sustentável, de uma forma geral, e menos impactante sobre a biodiversidade, em particular / Abstract: The sustainability of biofuels is a controversial issue, which gained large dimension since the second half of last decade. In this context, biodiversity is one of the most mentioned aspects in the international debate. Because of pressure from different social segments, sustainability criteria have been defined and have conditioned the application of policies to promote biofuels. In practice, certification schemes have been increasingly used and there is no indication that this trend will change. Thus, future production of ethanol from sugarcane in Brazil, and the competitiveness of national production in international markets, will depend on the fact that sustainability is a reality, and may be proved. In Brazil, very little is known about the impacts of sugarcane and ethanol production on biodiversity, and that was what motivated this dissertation. Its overall goal is to understand the issue biofuels-biodiversity, including the identification of existing knowledge, the different visions, aspirations, etc. The analysis was focused on the production of ethanol from sugarcane in Brazilian conditions, and perspectives. One of the specific objectives was defined in the assessment of certification schemes, and how biodiversity has been addressed. One of the conclusions of this dissertation is that very little is known about the impacts of biofuels on biodiversity, worldwide. Second, biodiversity is a complex issue that has many dimensions, and through a certification scheme is not possible to assess and monitor biodiversity as in scientific research. Furthermore, certification schemes are market instruments, and must be defined taking into account aspects as practicality, costs, and responsibilities that can be assigned to the economic agent that is certified. However, in general certification schemes of biofuels are stricter than certification schemes of forest and food products, and are aligned with the indicators recommended for energy companies. Anyway, certification mechanisms have an important role to play in fostering initiatives, in disseminating information and on differentiating producers and products. But the standards should be understood as complementary to public regulation, and thus they can be very useful. Finally, a conclusion of this dissertation is that the laws and regulations already available in Brazil regarding land use (e.g., the Forest Code, the Agro-ecologic Zoning and the definition of Priority Areas for Conservation) can be sufficient for avoiding or minimizing the potential impacts over biodiversity but, obviously, depending on their enforcement. With the existing legal and regulatory environment, combined with pressures from the market and from social actors, the sustainability of ethanol production from sugarcane in Brazil can be improved. This can result in even more sustainable production in general, and less impacts over biodiversity, in particular / Mestrado / Planejamento de Sistemas Energeticos / Mestra em Planejamento de Sistemas Energéticos

Orientador: Leila da Costa Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-23T21:25:46Z (GMT). No. of bitstreams: 1 Giesbrecht_Mariliad´Ottaviano_D.pdf: 1234541 bytes, checksum: a7f7ec34d9b6020bb07a19fd691102e2 (MD5) Previous issue date: 2013 / Resumo: Esta pesquisa tem como objetivo analisar o processo de institucionalização e desenvolvimento do Programa Nacional de Produção e Uso do Biodiesel (PNPB) no Brasil, lançado em 2004, com a missão de organizar a cadeia produtiva de biodiesel para sua introdução na matriz energética nacional. Tendo em vista as discussões e controvérsias mais amplas em torno do papel dos biocombustíveis na mitigação dos efeitos associados à mudança climática global, a criação do PNPB parece afirmar a posição favorável do governo brasileiro com relação ao uso e à produção de biocombustível líquido no debate internacional. Ao mesmo tempo, a elaboração do programa do biodiesel se mostrou sensível às questões estruturais da sociedade brasileira, tal como a problemática agrária e a dificuldade de inserção de uma parcela expressiva de pequenos produtores rurais no agromercado, propondo a inclusão deste setor na nascente cadeia produtiva do biodiesel. Uma das hipóteses defendidas por esta pesquisa é a de que a experiência histórica do Proálcool, implementado no Brasil, em 1975, singulariza o debate nacional atual sobre os biocombustíveis e, portanto, influencia fortemente as expectativas sociais, econômicas e ambientais depositadas no programa do biodiesel. Neste sentido, o processo de discussão, criação e institucionalização do PNPB revela também uma dinâmica política onde há, claramente, posições antagônicas no entendimento de como o processo de introdução do biodiesel na matriz energética nacional deve se dar. Há um dilema de interesses e forças que divide tanto as agências governamentais (ministérios e secretarias) envolvidas com o Programa do Biodiesel quanto os atores diretamente relacionados em todo o processo como os fabricantes de biocombustível, sojicultores, agricultores familiares: entre tornar o biodiesel um combustível viável técnica e economicamente ou fazer do biodiesel e sua cadeia produtiva um vetor de inclusão social. Este embate é verificado, sobretudo, na discussão do uso da mamona versus o uso da soja e, em geral, nos dilemas técnicos e científicos que o legitima. Finalmente, trata-se aqui de mostrar a partir do caso do PNPB, como a definição da noção de sustentabilidade é, a rigor, ela própria um móvel em disputa: é construída e significada sempre a partir dos modos como ela é concretamente praticada. Ou seja, a concepção de sustentabilidade é tão variada quanto os contextos políticos em que ela ganha forma, a despeito das inúmeras conceituações teóricas que tendem a cristalizá-la como passível de uma única definição possível / Abstract: This research aims to analyze the process of institutionalization and development of the National Biodiesel Production and Use Program (PNPB) in Brazil, launched in 2004 with the mission of organizing the biodiesel production chain for its introduction into the national energy matrix. In view of the broader discussion and controversy around the role of biofuels in mitigating the effects associated with global climate change, the creation of PNPB seems to affirm a favorable position of the Brazilian government regarding the use and production of liquid biofuel in this debate. At the same time, the development of the biodiesel program proved to be sensitive to structural issues in Brazilian society, as land problems and the difficulty of inserting a significant portion of small farmers in Agribusiness, suggesting the inclusion of this sector in the emerging biodiesel supply chain. One of the hypotheses proposed by this research is that the historical experience of the Alcohol Program, implemented in Brazil in 1975, singles out the current national debate about biofuels and therefore strongly influences the social, economic and environmental expectations deposited in the biodiesel program. The process of discussion, creation and institutionalization of PNPB also reveals a dynamic policy where there are clearly opposing viewpoints in understanding how the process of introduction of biodiesel in the national energy matrix must be given. There is a dilemma that divides both the government agencies (ministries, departments) involved in the Biodiesel Program, but also the actors directly related to the process, such as the manufacturers of biofuel, soybean farmers, family farmers: between making the biodiesel a viable fuel, technically and economically, or to make the biodiesel production and its productive chain an array of social inclusion. This divergence is found mainly in the discussion of the use of castor oil versus soy oil as biodiesel raw material and, in general, in the technical and scientifical dilemmas that supports and legitimizes it. Finally, the aim is to show, based in the PNPB case, how the definition of the notion of sustainability is, by and large, itself a disputed asset: it is always built and signified from the modes in which it is in fact practiced. Namely, the concept of sustainability is so diversified as are the political contexts in which it takes form, notwithstanding the innumerous theoretical conceptualizations that tend to crystalize it as subjected to a single definition / Doutorado / Aspectos Sociais de Sustentabilidade e Conservação / Doutora em Ambiente e Sociedade

The environmental conditions created in the Southwestern deserts of the United States are conducive to the production of green microalgae biomass, for use as a feedstock intended for conversion to carbon neutral liquid biodiesel. One promising heat-tolerant, rapidly-growing, high lipid content species is the chlorophyte, Chlorella sorokiniana (Shihira and Krauss, 1965) (isolate DOE 1412), which has been selected for pilot-scale production as part of a larger algal biofuels project to assess its potential for long-term productivity in open, outdoor monoculture production systems. Molecular analysis exposed the presence of the pathogenic bacterium, Vampirovibrio chlorellavorus (Gromov & Mamkaeva, 1972) causing infection and death of DOE 1412, which occurred most rapidly at air temperatures exceeding 34 °C. This Gram-negative bacterium has been reported to attach to and utilize the cellular contents of several Chlorella species, leading to yellowing and flocculation of algal cells, and death of the host. A quantitative PCR assay was developed to monitor pathogen accumulation using the 16S ribosomal RNA gene, in addition to the algal 18S ribosomal RNA gene for normalization. The assay is highly sensitive, with limits of quantification for the 16S and 18S gene targets calculated to be 19 and 131 copies, respectively. The qPCR assay was used to monitor several outdoor reactors inoculated with the DOE1412, throughout the warm season growth-to-harvest cycle to understand the disease cycle and inform disease management decisions. Further, the bacterium was monitored in paddlewheel DOE 1412 cultures treated with benzalkonium chloride (BAC), a biocide tested for the ability V. chlorellavorus attack of DOE 1412. The treatment resulted in a reduced growth rate for DOE 1412, but prolonged the duration of the production cycle resulting in increased total harvestable yield, compared to untreated control cultures.

>Magister Scientiae - MSc / The negative environmental impact of fossil fuels and growing concerns about petroleum supplies has driven the search for alternative, renewable transportation fuels. An 'ideal' fuel replacement would be a biofuel produced from lignocellulosic biomass. Unfortunately, the presence of lignin in plant cell walls impedes the breakdown of cell wall polysaccharides into simple sugars and the subsequent conversion of these sugars into useable fuels. One of the most common fates of lignin in nature is to be metabolized by lignin peroxidases (LiPs), predominantly of microbial origin. This study aims to isolate and characterise microorganism(s) involved in the degradation of lignocellulose. Thermophilic bacteria were isolated from straw-based compost and screened for lignin peroxidase activity. One isolate, CP11, showed significant lignin peroxidase activity and based on 16S rRNA gene sequence analysis, the isolate was found to be most closely related to Bacillus thermoamylovorans. Morphological, physiological and biochemical characterisation was conducted to determine whether the isolate was a novel species. Morphologically, CP11 was characterised as an endospore-forming, Gram positive rod. In addition, the isolate was found to be a facultative anaerobe, catalase positive and capable of utilising a range of carbon sources including glucose, sucrose and arabinose. Isolate CP11 was moderately thermotolerant and grew between 37°C and 55°C, with an optimum growth temperature of 45°C. Based on its phenotypic characteristics CP11 could be clearly distinguished from its closest phylogenetic neighbours. Preliminary characterisation of the lignin peroxidase was conducted using crude enzyme extract and Azure B dye as the substrate. Activity was detected in the supernatant only and a growth curve was constructed to determine the growth phase of lignin peroxidase production. In order to identify the gene encoding the lignin peroxidase a small insert library was constructed and screened for ligninase activity using Azure B as the substrate. / National Research Foundation

There is a huge global challenge to establish alternative forms of energy in order to cope with the increasing worldwide energy demand, currently based on finite fossil fuel reserves. In the transportation sector, renewable liquid fuels, such as bio-ethanol and biodiesel which are made from biomass and are substitutes for the petroleum-derived gasoline and diesel, have received increasing interest. In spite of their recent development, the biofuel industries cannot compete with conventional liquid fuels because of their higher costs. Decisive changes are required to improve their economic sustainability, such as the establishment of novel processes that utilize their by-products for the production of value-added chemicals. In this study, the bioconversion of glycerol, which is the main by-product of the biodiesel industry, to succinic acid by using the bacterium Actinobacillus succinogenes has been investigated both experimentally and computationally. Initially, the cells were adapted to accept a glycerol rich environment by performing a series of experiments. Cells from the best experiment from each run were used as inocula for the next experiment. Batch fermentations were then performed in small scale anaerobic reactors (SARs) and in lab-scale bench top reactors (B-TRs) by using the new ‘adapted’ strain. The maximum succinic acid yield, productivity and final concentration obtained from this bioprocess were found to be 1.29 g/g, 0.27 g/L/h and 29.3 g/L, respectively. Moreover, cells have also grown successfully in both synthetic and biodiesel-derived crude glycerol, indicating that it is not necessary to remove the impurities that biodiesel-derived glycerol contains. Subsequently, an unstructured model that accounts for substrate and product inhibition was developed in order to predict the behaviour of experiments starting from different initial conditions. Model predictions were found to be in good agreement with experimental data obtained for both systems (SARs and B-TRs). Batch and fed-batch systems were optimized using the developed model to obtain high succinic acid productivity. Optimization results showed that productivity increased by 31% for batch and 79% for fed-batch systems. The corresponding optimal values were computed to be equal to 0.356 g/L/h for batch and 0.488 g/L/h for fed-batch systems. A semi-mechanistic model for the fungal fermentation on solid state rapeseed meal (i.e. the other main by-product of the biodiesel industry) was also constructed for small scale tray bioreactors. This fermentation targets to increase the nutrient factor of the rapeseed meal by decomposing its macromolecules to simple compounds which can then be used as a generic medium. The developed model effectively predicts the fungal growth, the temperature fluctuations and the moisture content inside the bed and the produced extracellular enzymes that break the complex compounds of rapeseed meal (i.e. proteins) to free amino acids. The economic sustainability of biodiesel production was investigated by the construction of a plant model of an integrated biodiesel biorefinery for the production of fuels (biodiesel) and chemicals (succinic acid) in Aspen Plus®. For a biodiesel plant with capacity of 7.8 ktons per year, it was found that the plant’s profitability can be increased by 60% (considering a 20 years plant life and an interest rate of 7%) if a fermentation and recovery process for producing succinic acid is added. The integrated biorefinery scheme demonstrated the highest profits (€ 9.95 M.) when compared with other scenarios which either purified or disposed of the glycerol. These results illustrate the critical role of glycerol when it is utilized as a key renewable building block for the production of commodity chemicals. It is clear, based on this work, that future studies targeting the sustainable development of biodiesel biorefineries should focus their investigation on novel bio-processes, like the succinic acid fermentation, supplementing the production of fuels with the co-production of platform chemicals.

>Magister Scientiae - MSc / Second generation biofuels production requires a suite of lignocellulolytic enzymes, acting synergistically to liberate the fermentable monosaccharides contained within agricultural waste materials. The use of thermostable lignocellulosic enzymes in a high-temperature process represents a number of advantages over their respective mesophilic counterparts, including increased solubility of the polymeric lignocellulosic substrates, enhanced enzyme processivity and reduced risk of bacterial and/or phage contamination during fermentation (Turner et al., 2007; Viikari et al., 2007). Alpha-L-arabinofuranosidases (AFases) participate in the deconstruction of lignocellulosic materials by hydrolysing the arabinofuranosyl bonds contained within the hemicellulosic portion of lignocellulose. In this study, three AFases isolated from compost-derived metagenomic DNA were characterised. Three genes derived from the fosmid metagenomic library constructed from 70°C compost were cloned into the pET21a(+) expression vector and expressed in E. coli BL21. The heterologously expressed proteins, AFase_H4, AFase_E3 and AFase_D3, were subsequently purified and their biochemical characteristics determined. All three AFases were shown to be active between pH 4.0 and 6.0. AFase_H4 and AFase_E3 displayed the highest activity at 60oC, while AFase_D3 had an optimum temperature at 25oC. Furthermore, the three AFases had differing thermostability profiles. In particular, AFase_E3 maintains 100% residual activity following 60 min incubation at 80oC and 24 hour incubation at 60oC. All three AFases have activity upon p-Nitrophenyl-arabinofuranoside and none against a range of alternative p-Nitrophenylglycosidic substrates. Phylogenetic analysis of the catalytic domain, identified within the amino acid sequences of the AFases, suggests that these AFases belong to glycoside hydrolase (GH) family 51. The difference in the AFase primary amino acid sequence motifs were used to infer differences in thermostability. All three AFases indicated similar biochemical and biophysical characteristics. AFase_E3 was determined to be the most thermostable amongst all three AFases. In the assessment of the three AFases respective suitability for inclusion in thermogenic bioethanol production processes, AFase_E3 was concluded as a suitable candidate for hydrolysis and synergistic testing on natural substrates. AFase_D3 possess the potential to be included in novel mesophilic industrialized process.