To mitigate the problems of depleting and soaring price of fossil fuels, the production and use of renewable energy have been vigorously promoted. In Europe, the role of biologically-derived fuels and in particular biodiesel is gradually increasing in prominent. Rapeseed biodiesel is the most widely produced in Europe. As a consequence, enormous amount of by-products from production processes are being generated. Current strategies for managing these by-products (mainly rapeseed meal and crude glycerol) seem not to be economically sustainable. More efficient utilisation could add more value to the production chain which in turn would raise the competitiveness of biodiesel compared to petro-diesel. The aim of the project reported in this thesis was to study the feasibility of producing a value added product, polyhydroxybutyrate (PHB), from by-products generated from rapeseed biodiesel production processes as well as to investigate the effects of methanol, a major impurity in crude glycerol, on growth of Cupriavidus necator, a PHB-producing micro-organism.The preliminary study of C. necator growth in crude glycerol based media revealed that optimum concentration of crude glycerol was in a range 15-25 g/L. It was also found that slight changes in the carbon to nitrogen ratio of the feedstock did not significantly affect the growth while methanol at concentrations beyond 10 g/L did. A model based on a saturation equation was developed and used to successfully predict the inhibition of growth by methanol. From the developed model, mechanisms of the inhibition were proposed. The model could also be used to predict satisfactorily growth or productivity rates in other systems containing short-chain alcohols. The growth in solutions derived from rapeseed meal (designated as hydrolysate) via solid-state fermentation by Aspergillus oryzae followed by hydrolysis of the fermented solids was also studied. The biomass production was found to increase as a function of initial free amino nitrogen (FAN) concentration presented in the hydrolysate. However, at higher initial FAN concentrations, a lower conversion of nitrogen to biomass was observed. PHB production was studied using a feedstock which was a mixture of the hydrolysate and crude glycerol. Total biomass concentration reached 28.8 g/L at 120 h with 86% PHB content. PHB productivity and PHB yield on glycerol were 0.21 g/L•h and 0.32 g/g respectively. These results were comparable with those obtained when pure glycerol and synthetic crude glycerol were used, suggesting that, technically, the use of the generic rapeseed- and crude glycerol-based feedstock to produce PHB is feasible.Overall, the feasibility of producing PHB from rapeseed biodiesel by-products has been demonstrated. The satisfactory result leads to the more important outlook that the generic feedstock derived from rapeseed biodiesel by-products has the potential to be used to produce a wide range of products depending on the micro-organism used. Further development of this process to improve nutrient production efficiency as well as product yields and subsequent integration of the process into the biodiesel production process could well be an important contribution in the development of a sustainable biodiesel industry.

The presented dissertation thesis deals with the polymer polyhydroxybutyrate and other biopolymers as a basic building block for the construction of micro- and nanoscopic structures and materials used in food and cosmetics. In the theoretical part, current literary review is prepared to introduce the basics of this application field. The practical part of the work is composed of three blocks developed during the doctoral study. In the first and most important part are summarized comments to the academic and patent outputs, where among the academic ones it is possible to find two peer-reviewed articles dealing with the electrostatic and wet spinning of PHB and properties of prepared materials. The patent outputs consist of several accepted and applied projects, which summarize results on both PHB spinning methods, but also on general approaches enabling the processing of PHB into forms enabling many applications in food and cosmetics. Second part was focused on the patented composition of the UV protection cream based on the prepared nanoscopic and micro- morphologies of PHB. The third block summarizes results focused predominantly on the electrostatic spinning of PHB and other biopolymers. Finally, a short chapter containing a brief description of projects that were in a way related to the dissertation topic, but rather practical development work in Central Tanzania and West Africa, which draw on knowledge and contacts gained during studies at FCH BUT Brno.

The aim of this work is to study microbial production of polyhydroxyalkanoates (PHA). Theoretical part is focused on production of PHA using microoganisms and transgenic plants. Bacterial strain Cupriavidus necator H16 was used for laboratory production of PHA. Various waste oils were used as sole carbon and energy source. Salt of propionic adic and 1-propanol were used as intermediate for 3-hydroxyvalerate monomer (3HV) unit. Incorporation of 3HV to polymer can improve material features of PHA. The major part of experimental work was focused to study influence of aeration (concentration of dissolved oxygen) to bacterial growth, selected metabolic pathways and formation of PHA. Furthermore, influence of aeration to monomer composition of polymer was evaluated. According to experimental conclusion of this work it was approved dependance between aeration and monomer composition of PHA. Moreover, it was approved that higher concentration of oxygen supports bacterial growth and influences PHA content in cells. In addition, NADPH is one of the substrates influencing flux of acetyl-CoA throughout the metabolism; higher intracellular concentration of NADPH inhibits TCA cycle and enhances accumulation of PHA in cells. For this reason, specific enzymatic aktivity of several selected intracelular enzymes were measured, including those enzymes which can generate NADPH.

No description available.

Os polihidroxialcanoatos (PHAs) são poliésteres acumulados por microrganismos como material de reserva. O conhecimento das vias bioquímicas e enzimas envolvidas na biossíntese e degradação dos PHAs é uma importante ferramenta para auxiliar na produção industrial. A linhagem Burkholderia cepacia IPT64 é capaz de acumular uma blenda composta de P(3HB) e P(3H4PE) a partir de sacarose. Este trabalho está focado em duas das principais enzimas envolvidas na biossíntese de PHAs: a b-cetotiolase (phaA) e a PHA sintase (phaC). A primeira está associada à especificidade pelo substrato, e a segunda é considerada a enzima chave na síntese de PHAs. Neste trabalho a linhagem mutante phaC foi avaliada quanto à atividade enzimática de PHB sintase, que se constatou ter sido perdida. A presença de mais de uma tiolase no genoma de B. cepacia foi detectada. A inativação do gene phaABc identificado anteriormente, bloqueou totalmente a síntese de P(3HB), e não promoveu o aumento da quantidade total de polímero. Este resultado indica que a tiolase identificada é responsável direta do acúmulo de P(3HB). Outra indicação é que não há uma competição das vias de síntese dos dois polímeros P(3HB) e P(3H4PE), já que não houve alteração na quantidade de P(3H4PE) acumulado, mesmo quando P(3HB) deixou de ser acumulado. / The polyhydroxyalkanoates (PHAs) are polyesters accumulated by microorganisms as storage compounds. Knowing the biochemistry pathway and enzymes involved in the biosynthesis and degradation of PHAs is an important tool to help industrial production. The Burkholderia cepacia IPT64 strain is able to accumulate a blend of P(3HB) and P(3H4PE) from sucrose. The focus of this work is on the two main enzymes involved in PHA biosynthesis: the b-ketothiolase (phaA) and the PHA synthase (phaC). The first one is associated with substrate specificity, and the second one is considered the key enzyme in PHA synthesis. In this work a mutant strain phaC was evaluated on its PHB synthase enzymatic activity, that was discovered to have been lost. The presence of other thiolases in the B. cepacia genome was detected. The inactivation of phaABc gene identified previously, blocked totally the P(3HB) synthesis, and didnt increase the polymer content. This result indicates that the identified thiolase is directly responsible for P(3HB) accumulation. Another indication is that the synthesis pathways of the two polymers, P(3HB) and P(3H4PE), dont compete with each other, because the content of P(3H4PE) was not altered, even when the P(3HB) was not accumulated.

A utilização de produtos provenientes de fontes renováveis e livres de substâncias tóxicas é tendência global, prova disso é o constante aumento da demanda por produtos à base de madeira. Segundo o Forest Products Statistics (2015), a produção mundial de painéis de madeira reconstituída, em 2014, foi de 388 milhões de m³, um aumento de 5,5% em comparação com o ano anterior e um aumento de 34% quando comparado com 2010. No entanto, o setor industrial de painéis de madeira há décadas enfrenta um grande desafio com relação às emissões tóxicas vindas dos adesivos convencionais. Diante destes problemas, a proposta do presente trabalho foi testar a viabilidade da produção de painéis aglomerados e painéis OSB, com significativa redução da emissão de formaldeído, a partir de resíduos de madeira de Pinus sp. e Tectona grandis (Teca). Neste sentido, buscou-se contribuir para o aumento do conhecimento científico sobre a utilização do polímero natural polihidroxibutirato (PHB) e do resíduo de tinta à base de resina epóxi como adesivos alternativos. Os painéis foram fabricados variando-se os parâmetros de produção para obtenção de melhores condições de processo, sendo estes: densidade baixa, média e alta; teor de adesivo de 20, 30 e 40%; adição de partículas de Teca nas proporções de 0, 25, 50, 75, 100%. O desempenho físico-mecânico dos painéis foi avaliado com base nas normas ABNT NBR 14810 (2013) e ANSI A208.1 (2009). Realizou-se análise de variância (ANOVA) para testar a influência dos fatores individuais (densidade, percentual de adesivo e fração de Teca), além das interações entre tais fatores nas propriedades físico-mecânicas dos painéis. Os resultados apontaram para excelentes propriedades físicas e mecânicas dos painéis aglomerados de média e alta densidade, tendo resíduo de tinta, principalmente, nas proporções de 30 e 40%. Na maioria dos casos as propriedades de tais painéis foram superiores aos requisitos estipulados pela norma brasileira e pelas internacionais. Assim, ficou confirmada a viabilidade de produção dos aglomerados com pelo menos um dos insumos estudados bem como seu potencial de emprego para as finalidades compatíveis com produtos desta natureza. / The use of products from renewable sources and free of toxic substances is a global trend, the proof is the steady increase in demand for wood-based products. According to the Forest Products Statistics (2015), world production of reconstituted wood panels in 2014 was 388 million cubic meters, an increase of 5.5% compared to the previous year and an increase of 34% compared to 2010. However, the industrial sector of wood panels for decades faces a major challenge with regard to toxic emissions coming from conventional adhesives. Faced with these problems, the purpose of this study was to test the feasibility of production of panels and OSB panels, with significant reduction of formaldehyde emissions from wood waste Pinus sp. and teak (Teak). In this sense, we sought to contribute to the increase of scientific knowledge on the use of natural polymer polyhydroxybutyrate (PHB) and residual ink resin-based epoxy as alternative adhesives. The panels were manufactured by varying the production parameters to obtain the best processing conditions, namely: low density, medium and high; resin content of 20, 30 and 40%; adding particles of Teak in proportions of 0, 25, 50, 75, 100%. The physical-mechanical performance of the panels was evaluated based on the standards NBR 14810 (2013) and ANSI A208.1 (2009). Held analysis of variance (ANOVA) to test the influence of individual factors (density, adhesive percentage and fraction Teak), and the interactions among these factors in the physical-mechanical properties of the panels. The results showed excellent physical and mechanical properties of the panels average clusters and high density, and ink residue, mainly in the proportions of 30 and 40%. In most cases the properties of these boards were superior to the requirements set by the Brazilian and international standards. Thus, it was confirmed production of agglomerates with at least one viability of inputs studied as well as their potential for employment for purposes compatible with products of this nature.

Made available in DSpace on 2016-12-08T17:19:36Z (GMT). No. of bitstreams: 1 Marcia Adriana Tomaz.pdf: 5577367 bytes, checksum: c8f9d4ee034ae6bd90f26bb87ca29b3c (MD5) Previous issue date: 2004-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Aiming the development of high-performance biodegradable polymeric materials, the properties and the processing behavior of poly(3-hydroxibutyrate), PHB, and their blends with poly(ε-caprolactone), PCL, have been investigated. Two sample of PHB obtaneid from sugarcane and characterized by infrared spectroscopy and X-ray diffraction, with molecular weights of 2,4 x 105 g.mol 1, PHB(A) and 3,0 x 105 g.mol 1,PHB(B), were used. Differential scanning calorimetry (DSC) showed that the sample were different regarding the crystallinity degree, 49% for the PHB(A) and 60% for the PHB(B), the glass transition temperature (Tg), 2,0oC (A) and 4,4 oC (B), and the melting temperature, 178oC (A) and 171oC (B). The samples have been processed through high-pressure compacting,solid state extrusion, and injection molding. Cylindrical billets of PHB prepared by compaction at 200 MPa showed high shore hardness, 71,3 (±0,9) D, and compression strength, 51,7 (± 1,0) MPa. The solid state processing was carried out by uniaxial compression, at temperature between the Tg and the melting point, through conical dies with extrusion draw ratio of 25 . It has produced extremely fragile materials with very high crystalline degrees (ca. 90%). Specimens of PHB(B) obtaneid by injection molding showed tensile strength, 24.53 (±0,77) MPa, and modulus ,3.82 (± 0,06) GPa, compatible to diverse type of applications. A small decrease on the tensile strength, 21,88 (± 0,40) MPa, and modulus, 2,17 (±0,25) GPa, and a high increase on the elongation at break, 86.7% (±20,0) were noted for PHB(B)/PCL (70/30) blends prepared by injection molding. DSC analyses of this blend showed two Tg´s, at 10,6oC for the PHB matrix, and at 62,9 oC for the PCL domains. The significant decrease on the Tg of PHB in the blend is possibly related to a partial miscibility of PCL in PHB. Thermal degradation studies of PHB were carried out by thermogravimetric methods, showing that the degradations occurs in only one step and that the presence of oxygen does not interfere in the degradation process. / Visando o desenvolvimento de materiais poliméricos biodegradáveis de alta performance estudaram-se as propriedades e o processamento de poli(3-hidroxibutirato), PHB, e de suas blendas com poli(ε-caprolactona), PCL. Foram utilizadas duas amostras de PHB, obtidas a partir de cana de açúcar,com massas molares de 2,4 x 105 g mol-1, PHB(A) e 3,0 x 105 g mol-1, PHB(B), cujas identidades foram confirmadas por espectroscopia na região do infravermelho. A calorimetria diferencial exploratória (DSC) mostrou que as amostras se diferenciam quanto ao grau de cristalinidade, 49% para o PHB(A) e 60% para o PHB(B), e em relação às temperaturas de transição vítrea, que variaram de 2 oC a 4,4oC, e de fusão, de 178 oC a 171 oC. Os materiais foram processados por compactação a alta pressão, extrusão em estado sólido e injeção em molde. O material compactado a 200 MPa apresentou elevada dureza, 71,30 (±0,9) unidades Shore D, e alta resistência à compressão, 51,7 (± 1,0) MPa. Observou-se que o processamento no estado sólido com razão de extrusão de 25 e em temperaturas até 175oC geram materiais extremamente frágeis, sendo que a caracterização por microscopia eletrônica de varredura mostra que o material não estava consolidado. A análise de DSC deste material revelou um alto grau de cristalinidade (93%), o que provavelmente está relacionado com a grande dificuldade de se obter PHB ou suas blendas com PCL por extrusão sólida. Corpos de prova de PHB(B) obtidos por injeção em molde apresentaram valores de resistência à tração, 24,53 (± 0,77) MPa,compatíveis com diversos tipos de aplicações, enquanto que as blendas de PHB(B)/PCL (70/30) injetadas apresentaram módulo de elasticidade igual a 2,17 (± 0,25) GPa e resistência à tração de 21,88 (± 0,40) MPa. A análise de DSC da blenda apresentou duas Tg´s, uma em -10,6 oC, da matriz de PHB, e outra a 62,9 oC, referente aos domínios de PCL. A diminuição acentuada na Tg do PHB(B) pode estar associada a uma provável solubilidade do PCL em PHB. Estudos da degradação térmica do PHB(B) por análise termogravimétrica, mostram que a degradação ocorre em apenas uma etapa e que a presença de oxigênio não interfere na degradação. Na análise da blenda de PHB(B)/PCL (70/30) é possível observar dois estágios de degradação provenientes do PHB(B) e do PCL e uma diminuição nas temperaturas de início de degradação do PCL e do PHB, quando comparadas com as dos materiais não processados.

Os polihidroxialcanoatos (PHAs) são poliésteres acumulados por microrganismos como material de reserva. O conhecimento das vias bioquímicas e enzimas envolvidas na biossíntese e degradação dos PHAs é uma importante ferramenta para auxiliar na produção industrial. A linhagem Burkholderia cepacia IPT64 é capaz de acumular uma blenda composta de P(3HB) e P(3H4PE) a partir de sacarose. Este trabalho está focado em duas das principais enzimas envolvidas na biossíntese de PHAs: a b-cetotiolase (phaA) e a PHA sintase (phaC). A primeira está associada à especificidade pelo substrato, e a segunda é considerada a enzima chave na síntese de PHAs. Neste trabalho a linhagem mutante phaC foi avaliada quanto à atividade enzimática de PHB sintase, que se constatou ter sido perdida. A presença de mais de uma tiolase no genoma de B. cepacia foi detectada. A inativação do gene phaABc identificado anteriormente, bloqueou totalmente a síntese de P(3HB), e não promoveu o aumento da quantidade total de polímero. Este resultado indica que a tiolase identificada é responsável direta do acúmulo de P(3HB). Outra indicação é que não há uma competição das vias de síntese dos dois polímeros P(3HB) e P(3H4PE), já que não houve alteração na quantidade de P(3H4PE) acumulado, mesmo quando P(3HB) deixou de ser acumulado. / The polyhydroxyalkanoates (PHAs) are polyesters accumulated by microorganisms as storage compounds. Knowing the biochemistry pathway and enzymes involved in the biosynthesis and degradation of PHAs is an important tool to help industrial production. The Burkholderia cepacia IPT64 strain is able to accumulate a blend of P(3HB) and P(3H4PE) from sucrose. The focus of this work is on the two main enzymes involved in PHA biosynthesis: the b-ketothiolase (phaA) and the PHA synthase (phaC). The first one is associated with substrate specificity, and the second one is considered the key enzyme in PHA synthesis. In this work a mutant strain phaC was evaluated on its PHB synthase enzymatic activity, that was discovered to have been lost. The presence of other thiolases in the B. cepacia genome was detected. The inactivation of phaABc gene identified previously, blocked totally the P(3HB) synthesis, and didnt increase the polymer content. This result indicates that the identified thiolase is directly responsible for P(3HB) accumulation. Another indication is that the synthesis pathways of the two polymers, P(3HB) and P(3H4PE), dont compete with each other, because the content of P(3H4PE) was not altered, even when the P(3HB) was not accumulated.

A utilização de produtos provenientes de fontes renováveis e livres de substâncias tóxicas é tendência global, prova disso é o constante aumento da demanda por produtos à base de madeira. Segundo o Forest Products Statistics (2015), a produção mundial de painéis de madeira reconstituída, em 2014, foi de 388 milhões de m³, um aumento de 5,5% em comparação com o ano anterior e um aumento de 34% quando comparado com 2010. No entanto, o setor industrial de painéis de madeira há décadas enfrenta um grande desafio com relação às emissões tóxicas vindas dos adesivos convencionais. Diante destes problemas, a proposta do presente trabalho foi testar a viabilidade da produção de painéis aglomerados e painéis OSB, com significativa redução da emissão de formaldeído, a partir de resíduos de madeira de Pinus sp. e Tectona grandis (Teca). Neste sentido, buscou-se contribuir para o aumento do conhecimento científico sobre a utilização do polímero natural polihidroxibutirato (PHB) e do resíduo de tinta à base de resina epóxi como adesivos alternativos. Os painéis foram fabricados variando-se os parâmetros de produção para obtenção de melhores condições de processo, sendo estes: densidade baixa, média e alta; teor de adesivo de 20, 30 e 40%; adição de partículas de Teca nas proporções de 0, 25, 50, 75, 100%. O desempenho físico-mecânico dos painéis foi avaliado com base nas normas ABNT NBR 14810 (2013) e ANSI A208.1 (2009). Realizou-se análise de variância (ANOVA) para testar a influência dos fatores individuais (densidade, percentual de adesivo e fração de Teca), além das interações entre tais fatores nas propriedades físico-mecânicas dos painéis. Os resultados apontaram para excelentes propriedades físicas e mecânicas dos painéis aglomerados de média e alta densidade, tendo resíduo de tinta, principalmente, nas proporções de 30 e 40%. Na maioria dos casos as propriedades de tais painéis foram superiores aos requisitos estipulados pela norma brasileira e pelas internacionais. Assim, ficou confirmada a viabilidade de produção dos aglomerados com pelo menos um dos insumos estudados bem como seu potencial de emprego para as finalidades compatíveis com produtos desta natureza. / The use of products from renewable sources and free of toxic substances is a global trend, the proof is the steady increase in demand for wood-based products. According to the Forest Products Statistics (2015), world production of reconstituted wood panels in 2014 was 388 million cubic meters, an increase of 5.5% compared to the previous year and an increase of 34% compared to 2010. However, the industrial sector of wood panels for decades faces a major challenge with regard to toxic emissions coming from conventional adhesives. Faced with these problems, the purpose of this study was to test the feasibility of production of panels and OSB panels, with significant reduction of formaldehyde emissions from wood waste Pinus sp. and teak (Teak). In this sense, we sought to contribute to the increase of scientific knowledge on the use of natural polymer polyhydroxybutyrate (PHB) and residual ink resin-based epoxy as alternative adhesives. The panels were manufactured by varying the production parameters to obtain the best processing conditions, namely: low density, medium and high; resin content of 20, 30 and 40%; adding particles of Teak in proportions of 0, 25, 50, 75, 100%. The physical-mechanical performance of the panels was evaluated based on the standards NBR 14810 (2013) and ANSI A208.1 (2009). Held analysis of variance (ANOVA) to test the influence of individual factors (density, adhesive percentage and fraction Teak), and the interactions among these factors in the physical-mechanical properties of the panels. The results showed excellent physical and mechanical properties of the panels average clusters and high density, and ink residue, mainly in the proportions of 30 and 40%. In most cases the properties of these boards were superior to the requirements set by the Brazilian and international standards. Thus, it was confirmed production of agglomerates with at least one viability of inputs studied as well as their potential for employment for purposes compatible with products of this nature.

Des produits de consommation de première nécessité aux produits les plus fortuits, l'emballage, en particulier plastique, constitue aujourd'hui un élément indispensable de notre vie quotidienne. Son utilisation intensive dans le domaine agroalimentaire pour un usage unique à courte durée de vie incite aujourd'hui à s'orienter vers de nouveaux matériaux d'origine renouvelable et biodégradables, aux caractéristiques similaires que leurs homologues issus des ressources fossiles. Les mélanges à base de biopolymères et de biopolyesters peuvent être une bonne alternative. Dans ce présent travail de thèse, des mélanges de farine de blé, thermoplastifiée par du glycérol et de l'eau, et des polyesters biosourcés et biodégradables tels que le PLA et/ou le PHB ont été obtenus par extrusion bivis et moulés par injection thermoplastique. Les caractéristiques thermiques, thermomécaniques dynamiques, morphologiques, mécaniques et barrières de ces nouveaux matériaux ont été étudiés. De l'acide citrique a été utilisé comme agent de compatibilisant pour améliorer l'interface amidon/PLA. Les différentes investigations nous ont permis de mettre au point différents types de formulations aux caractéristiques mécaniques et barrières à la vapeur d'eau intéressantes pour la fabrication de corps de barquettes d'emballage alimentaire de denrées périssables comme la viande ou les fromages. L'aptitude au contact alimentaire des matériaux farine thermoplastifiée/polyester et l'impact de l'incorporation des polyesters sur la biodégradabilité de ces matériaux ont également été étudiés. / From basic and essential to unnecessary and optional consumer products, packaging, particularly plastic, is today an indispensable part of our daily life. Its extensive use in the food industry for a single use and for a short shelf-life encourages us today to move towards new renewable and biodegradable materials with similar characteristics than their counterparts from fossil resources. Biopolymers and biopolyesters blends can be a good alternative. Within the framework of this present work, wheat flour, thermoplasticised by glycerol and water, and biobased and biodegradable polyesters such as PLA and/or PHB, were blended using an industrial twin screw extruder and were injection-molded into thermoplastic materials. Thermal, dynamic thermomechanical, morphological, mechanical and barriers properties of these new materials were studied. Citric acid was used as a compatibilizer to improve the interface starch/PLA. The different investigations have allowed us to develop various types of formulations, with mechanical characteristics and barrier properties to water vapor, very attractive for manufacturing plastic food packaging which can be used for meats or cheeses. Food contact suitability and biodegradability of thermoplasticised wheat flour/polyester materials have also studied.