ABOVE-GROUND BIOMASS ESTIMATION OF OPUNTIA FICUS-INDICA (L.) MILL. FOR FORAGE CROP IN A MEDITERRANEAN ENVIRONMENT BY USING NON-DESTRUCTIVE METHODS

In marginal lands Opuntia ficus-indica (OFI) could be used as an alternative fruit and forage crop. The plant vigour and the biomass production were evaluated in Portuguese germplasm (15 individuals from 16 ecotypes) by non-destructive methods, 2 years following planting in a marginal soil and dryland conditions. Two Italian cultivars (Gialla and Bianca) were included in the study for comparison purposes. The biomass production and the plant vigour were estimated by measuring the cladodes number and area, and the fresh (FW) and dry weight (DW) per plant. We selected linear models by using the biometric data from 60 cladodes to predict the cladode area, the FW and the DW per plant. Among ecotypes, significant differences were found in the studied biomass-related parameters and several homogeneous groups were established. Four Portuguese ecotypes had higher biomass production than the others, 3.20 Mg ha−1 on average, a value not significantly different to the improved ‘Gialla’ cultivar, which averaged 3.87 Mg ha−1. Those ecotypes could be used to start a breeding program and to deploy material for animal feeding and fruit production.

Portuguese ecotypes of Opuntia ficus-indica differ in biomass production

The Opuntia ficus-indica (L.) Miller is a species from the Cactaceae family with the center of origin and domestication in central Mexico. This species introduction in the Iberia Peninsula occurred, probably, by the end of the 15th century, after the discovery of America, spreading later throughout the Mediterranean basin. In Portugal, O. ficus-indica is located, usually, with a typical ruderal behavior, at the edge of roads and paths. In Portugal, as in other Mediterranean regions, inlands areas are under severe draught during extensive summers, in particular, and global warming is expected to affect them deeply in the near future. O. ficus-indica, by its morpho-physiological characteristics and multiple economic uses, represent an alternative crop for those regions. Sixteen Portuguese O. ficus indica ecotypes and two ‘Italian’ cultivars ("Gialla" and "Bianca") were evaluated for plant vigor and biomass production, by nondestructive methods, in the two years following planting. Biomass production and plant vigor were measured by estimating cladode number, cladode area and fresh weight per plant. Linear models to predict the area of cladodes and fresh weight per plant were previously established using a biometric analysis of 180 cladodes. It was not possible to establish an accurate linear model for dry matter using non-destructive estimation. Significant differences were found among populations in the studied biomass-related parameters, and different groups were unfolded. A group of four Portuguese ecotypes outperformed in terms of biomass production, comparable with the “Gialla” cultivar. This group could be used to start a breeding program with the objective of deploy material for animal feeding, biomass and fruit production. Nevertheless, the ‘Gialla’ cultivar showed the best performance, achieving the highest biomass related parameters, not surprisingly for it is an improved plant material.

Characterization of pyrolysis and oxidation processes of biomaterials, biomasses and biofuels

The urgent need for alternative solutions mitigating the impacts of human activities on the environment has strongly opened new challenges and opportunities in view of the energy transition. Indeed, the automotive industry is going through a revolutionary moment in its quest to reduce its carbon footprint, with biofuels being one of the viable alternatives. The use of different classes of biofuels as fuel additives/standalone components has attracted the attention of many researchers. Despite their beneficial effects, biofuel’s combustion can also result in the production of undesirable pollutants, requiring complete characterization of the phenomena occurring during their production and consumption. Industrial scale-up of biomass conversion is challenging owing to the complexity of its chemistry and transport phenomena involved in the process. In this view, the role of solid-phase and gas-phase chemistry is paramount. Thus, this study is devoted to detailed analysis of physical-chemical phenomena characterizing biomass pyrolysis and biofuel oxidation. The pyrolysis mechanism has been represented by 20 reactions whereas, the gas-phase kinetic models; manually upgraded model (KiBo_MU) and automated model (KiBo_AG), comprises 141 species and 453 reactions, and 631 species and 28329 reactions, respectively. The accuracy of the kinetic models was tested against experimental data and the models captured experimental trends very well. While the development and validation of detailed kinetic mechanisms is the main deliverable of this project, the realized procedure integrating schematic classifications with methodologies for the identification of common decomposition pathways and intermediates represents an additional source of novelty. Besides, the fundamentally oriented nature of the adopted method allows the identification of most relevant reactions and species under the operating conditions different industrial applications, paving the way for reduced kinetic mechanisms. Ultimately, the resulting detailed mechanisms can be used to integrate with more complex fluid dynamics model to accurately reproduce the behavior of real systems and reactors.

Development of processes for the valorization of lignocellulosic biomass based on renewable energies

The world grapples with climate change from fossil fuel reliance, prompting Europe to pivot to renewable energy. Among renewables, biomass is a bioenergy and bio-carbon source, used to create high-value biomolecules, replacing fossil-based products. Alkyl levulinates, derived from biomass, hold promise as bio-additives and biofuels, especially via acid solvolysis of hexose sugars, necessitating further exploration. Alkyl levulinate's potential extends to converting into γ-valerolactone (GVL), a bio-solvent produced via hydrogenation with molecular-hydrogen. Hydrogen, a key reagent and energy carrier, aids renewable energy integration. This thesis delves into a biorefinery system study, aligning with sustainability goals, integrating biomass valorization, energy production, and hydrogen generation. It investigates optimizing technologies for butyl levulinate production and subsequent GVL hydrogenation. Sustainability remains pivotal, reflecting the global shift towards renewable and carbon bio-resources. The research initially focuses on experimenting with the optimal technology for producing butyl levulinate from biomass-derived hexose fructose. It examines the solvolysis process, investigating optimal conditions, kinetic modeling, and the impact of solvents on fructose conversion. The subsequent part concentrates on the technological aspect of hydrogenating butyl levulinate into GVL. It includes conceptual design, simulation, and optimization of the fructose-to-GVL process scheme based on process intensification. In the final part, the study applies the process to a real case study in Normandy, France, adapting it to local biomass availability and wind energy. It defines a methodology for designing and integrating the energy-supply system, evaluating different scenarios. Sustainability assessment using economic, environmental, and social indicators culminates in an overall sustainability index, indicating scenarios integrating the GVL biorefinery system with wind power and hydrogen energy storage as promising due to high profitability and reduced environmental impact. Sensitivity analyses validate the methodology's reliability, potentially extending to other technological systems.

Resolução do ibuprofeno: um projeto para disciplina de química orgânica experimental

A practical and didactic sequence of experiments was proposed to illustrate the stereochemistry concept, optically active compounds, resolution of racemates, and use of the NMR technique, including 2D-COSY for identification of organic compounds, on a laboratory course for undergraduate students. The sequence was: extractions of racemic ibuprofen and chiral naproxen from commercial tablets; syntheses of diastereoisomeric amides reacting chiral (S)-(-)-α-methylbenzylamine with (±)-ibuprofen; separation and determination of absolute configuration of amides by ¹H NMR spectroscopy and GC analysis, and hydrolysis of amides to obtain (+)- and (-)-ibuprofen.

Total carbon measurement in whole tropical soil sample

Soils are an important component in the biogeochemical cycle of carbon, storing about four times more carbon than biomass plants and nearly three times more than the atmosphere. Moreover, the carbon content is directly related on the capacity of water retention, fertility. among other properties. Thus, soil carbon quantification in field conditions is an important challenge related to carbon cycle and global climatic changes. Nowadays. Laser Induced Breakdown Spectroscopy (LIBS) can be used for qualitative elemental analyses without previous treatment of samples and the results are obtained quickly. New optical technologies made possible the portable LIBS systems and now, the great expectation is the development of methods that make possible quantitative measurements with LIBS. The goal of this work is to calibrate a portable LIBS system to carry out quantitative measures of carbon in whole tropical soil sample. For this, six samples from the Brazilian Cerrado region (Argisoil) were used. Tropical soils have large amounts of iron in their compositions, so the carbon line at 247.86 nm presents strong interference of this element (iron lines at 247.86 and 247.95). For this reason, in this work the carbon line at 193.03 nm was used. Using methods of statistical analysis as a simple linear regression, multivariate linear regression and cross-validation were possible to obtain correlation coefficients higher than 0.91. These results show the great potential of using portable LIBS systems for quantitative carbon measurements in tropical soils. (C) 2008 Elsevier B.V. All rights reserved.

A New Approach to Ammonium Sulphate Feeding for Fed-Batch Arthrospira (Spirulina) platensis Cultivation in Tubular Photobioreactor

Arthrospira platensis was cultivated in tubular photobioreactor using different photosynthetic photon flux densities (PPFD) and protocols of (NH(4))(2)SO(4) fed-hatch supply. Results were evaluated by variance analysis selecting maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N)) and biomass, protein and lipid contents as responses. At PPFD of 120 and 240 mu mol-photons/m(2) s, a parabolic profile of (NH(4))(2)SO(4) addition aiming at producing biomass with 7% nitrogen content ensured X(m) values (14.1 and 12.2 g/L, respectively) comparable to those obtained with NaNO(3). At PPFD of 240 mu mol-photons/m(2) s, P(x) (1.69 g/Ld) was 36% higher, although the photosynthetic efficiency (3.0%) was less than one-half that at PPFD of 120 mu mol-photons/m(2) s. Biomass was shown to be constituted by about 35% proteins and 10% lipids, without any dependence on PPFD or kind of nitrogen source. These results highlight the possible use of (NH(4))(2)SO(4) as alternative, cheap nitrogen source for A. platensis cultivation in tubular photobioreactors. (C) 2010 American Institute of Chemical Engineers Biotechnol. Prog., 26: 1271-1277, 2010

Synthesis of anatase TiO2 supported on porous solids by chemical vapor deposition

Coating anatase TiO2 onto three different particle supports, activated carbon (AC), gamma -alumina (Al2O3) and silica gel (SiO2), by chemical vapor deposition (CVD) was studied. The effect of the CVD synthesis conditions on the loading rate of anatase TiO2 was investigated. It was found that introducing water vapor during CVD or adsorbing water before CVD was crucial to obtain anatase TiO2 on the surface of the particle supports. The evaporation temperature of precursor, deposition temperature in the reactor, flow rate of carrier gas, and the length of coating time were also important parameters to obtain more uniform and repeatable TiO2 coating. High inflow precursor concentration, high CVD reactor temperature and long coating time tended to cause block problem. Coating TiO2 onto small particles by CVD involved both chemical vapor deposition and particle deposition. It was believed that the latter was the reason for the block problem. In addition, the mechanism of CVD process in this study included two parts, pyrolysis and hydrolysis, and one of them was dominant in the CVD process under different synthesis route. Among the three types of materials, silica gel, with higher surface hydroxyl groups and macropore surface area, was found to be the most efficient support in terms of both anatase TiO2 coating and photocatalytic reaction. (C) 2001 Elsevier Science B.V. All rights reserved.

Is maximizing resilience compatible with established ecological goal functions?

Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] used a simple phytoplanktonzooplankton-nutrient model and a genetic algorithm to determine the parameter values that would maximize the value of certain goal functions. These goal functions were to maximize biomass, maximize flux, maximize flux to biomass ratio, and maximize resilience. It was found that maximizing goal functions maximized resilience. The objective of this study was to investigate whether the Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] result was indicative of a general ecosystem principle, or peculiar to the model and parameter ranges used. This study successfully replicated the Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] experiment for a number of different model types, however, a different interpretation of the results is made. A new metric, concordance, was devised to describe the agreement between goal functions. It was found that resilience has the highest concordance of all goal functions trialled. for most model types. This implies that resilience offers a compromise between the established ecological goal functions. The parameter value range used is found to affect the parameter versus goal function relationships. Local maxima and minima affected the relationship between parameters and goal functions, and between goal functions. (C) 2003 Elsevier B.V. All rights reserved.

Efeitos da depleção de nitrogênio sobre a biomassa e produção lipídica lipídica de três espécies de microalgas fitoplânticas

O uso de lipídios obtidos a partir da biomassa de microalgas tem sido descrito como uma alternativa promissora para a indústria petro-diesel e envolve etapas como o cultivo de microalgas, separação da biomassa e extração de lipídios. Para viabilizar a produção em larga escala, é necessário selecionar as espécies mais produtivas, diminuir os custos de produção e determinar as condições ideais de cultivo. Os gêneros Chlorella, Desmodesmus e Ankistrodesmus apresentam características favoráveis à produção comercial, tendo sido então selecionada uma espécie de cada no presente trabalho. O objetivo do estudo foi avaliar diferentes condições de cultivo de Ankistrodesmus fusiformis, Chlorella vulgaris e Desmodesmus spinosus visando o aumento da produtividade em biomassa e lipídios totais. As algas foram identificadas e cultivadas em laboratório, em condições controladas de temperatura a 26ºC (±1), aeração por borbulhamento à pressão ambiente e luminosidade fornecida por lâmpadas fluorescentes, com intensidade de 47,25 μmol de fótons m-2.s-1 (3500 lux), fotoperiodo de 12h e pH 7, sob duas concentrações estressantes de nitrato de sódio (0,10 g/L e 0,05g/L). Os cultivos duraram em média 16 dias, sendo as curvas de crescimento construídas com dados de espectrofotometria óptica coletados a cada 48h, e a biomassa obtida ao final do cultivo por centrifugação e liofilização de cada unidade experimental. Para extração dos lipídios totais, foi utilizada a mistura de clorofórmio: metanol (1:2), segundo a metodologia de Bligh & Dyer (1959). Os tratamentos de estresse em D.spinosus resultaram em maior acúmulo lipídico, com aumento de até 149,7%, porém com drástica diminuição do crescimento e biomassa. Em C. vulgaris, nos tratamentos de estresse, verificou-se apenas ligeiro aumento do peso seco e teor de lipídios, não havendo diferença significativa entre os tratamentos e o controle. Da mesma forma, A.fusiformis não mostrou respostas significativas ao estresse pela redução de nitrato de sódio do meio, havendo ligeira diminuição do conteúdo lipídico e aumento do crescimento e biomassa. Com respostas diferentes para cada espécie estudada, evidencia-se a necessidade do conhecimento da fisiologia e autoecologia da cepa a ser cultivada em escala comercial visando à produção de ácidos graxos para fins de biodiesel.

Targeting lactate transport suppresses in vivo breast tumour growth

Background: Most cancers, including breast cancer, have high rates of glucose consumption, associated with lactate production, a process referred as “Warburg effect”. Acidification of the tumour microenvironment by lactate extrusion, performed by lactate transporters (MCTs), is associated with higher cell proliferation, migration, invasion, angiogenesis and increased cell survival. Previously, we have described MCT1 up-regulation in breast carcinoma samples and demonstrated the importance of in vitro MCT inhibition. In this study, we performed siRNA knockdown of MCT1 and MCT4 in basal-like breast cancer cells in both normoxia and hypoxia conditions to validate the potential of lactate transport inhibition in breast cancer treatment. Results: The effect of MCT knockdown was evaluated on lactate efflux, proliferation, cell biomass, migration and invasion and induction of tumour xenografts in nude mice. MCT knockdown led to a decrease in in vitro tumour cell aggressiveness, with decreased lactate transport, cell proliferation, migration and invasion and, importantly, to an inhibition of in vivo tumour formation and growth. Conclusions: This work supports MCTs as promising targets in cancer therapy, demonstrates the contribution of MCTs to cancer cell aggressiveness and, more importantly, shows, for the first time, the disruption of in vivo breast tumour growth by targeting lactate transport.

Estudo do desempenho de betões com incorporação de agregados finos provenientes de resíduos industriais

A crescente preocupação relacionada com a sustentabilidade ambiental e o risco de esgotamento de recursos naturais, tem levado à necessidade de encontrar novos materiais e novas técnicas construtivas. Nesse pressuposto, o presente trabalho tem como principal objetivo avaliar a viabilidade de utilização de resíduos provenientes de indústrias da região (lamas de cal e cinzas de biomassa) em produção de betões que possam vir a ser utilizados na construção civil. Neste sentido, desenvolveu-se uma campanha experimental com o intuito de comparar desempenho de sete tipos diferentes de betões: um de referência e seis com taxas de substituição de 20, 50 e 100% de agregados finos naturais por cinzas de biomassa e lamas de cal. A composição dos diferentes betões foi determinada pelo método de Faury, cumprindo-se as exigências na norma NP EN 206-1. O desempenho dos betões foi avaliado através da análise dos resultados de ensaios sobre o betão fresco (consistência, massa volúmica e teor de ar) e sobre o betão endurecido (massa volúmica, resistência à compressão, resistência à tração por compressão diametral, absorção de água por capilaridade e absorção de água por imersão). No presente trabalho, procedeu-se, também, à realização de ensaios químicos aos betões produzidos (lixiviação). No final do trabalho é feita uma discussão dos resultados experimentais e são evidenciadas as principais conclusões deste estudo.

Estudo da influência das condições de armazenamento nas propriedades e composição do biodiesel

O objectivo deste trabalho era a determinação da influência das condições de armazenamento do biodiesel nas suas propriedades e composição. Para isso foi produzido biodiesel a partir de óleo alimentar usado e armazenado em diferentes condições. O biodiesel foi colocado em frascos de vidro e dividido em três grupos diferentes de temperatura. O primeiro foi colocado a uma temperatura de 6ºC (frigorifico) com frascos fechados e expostos ao ar e água. O segundo grupo foi colocado a uma temperatura de 40ºC (banho termostático) com frascos fechados, abertos ao ar e abertos ao ar e água. O terceiro e ultimo grupo foi colocado à temperatura ambiente (18,6ando de seguida uma tendência decrescente. O aumento inicial corresponde à formação de hidroperóxidos, já o declínio provavelmente corresponderá à sua degradação e formação de compostos como aldeídos. Os aldeídos por sua vez oxidam e dão origem a ácidos, justificando assim o aumento do índice de acidez. Este índice pode aumentar também devido à hidrólise dos ésteres causada pela presença de água, dando origem a álcoois e ácidos. Em contrapartida para as amostras armazenadas a temperaturas mais baixas os parâmetros mantiveram-se praticamente constantes ao longo do tempo. O índice de iodo não permitiu concluir claramente que houve uma diminuição nas ligações duplas como seria espectável. Ao analisar os cromatogramas obtidos na determinação dos ésteres das amostras armazenadas em contacto com ar e água, a 40ºC verifica-se a formação de ácidos gordos a partir dos 81 dias de armazenamento. Com os resultados obtidos verificou-se que para as amostras colocadas a 40ºC e em contacto com ar e água a taxa de oxidação é mais acelerada, fazendo com que o biodiesel perca as características e propriedades iniciais, já no caso das amostras armazenadas a 6ºC e em frascos fechados verifica-se que os parâmetros estudados praticamente não sofrem alterações, mantendo quase inalteradas as propriedades e composição do biodiesel ao fim das 16 semanas de estudo. Assim é possível concluir que para se conseguir manter as características e propriedades do biodiesel durante um armazenamento prolongado é necessário garantir um ambiente fresco de preferência inerte e depósitos completamentos secos, de forma a evitar as condições que provocam oxidação.

Optimization of bioplastics production from cheese whey

Dissertation presented in partial fulfillment of the requirements for the degree of Master in Biotechnology

Valorização da Drêche Cervejeira: Fermentação de Pentoses

O presente trabalho tem como objetivo a otimização da etapa de fermentação dos açúcares obtidos a partir da drêche cervejeira para produção do bioetanol através da utilização das leveduras Pichia stipitis NCYC 1541 e Kluyveromyces marxianus NCYC 2791 como agentes fermentativos. O meio de cultura usado para manter as culturas destas leveduras foi Yeast Extract Peptone Dextrose (YEPD). O principal propósito deste trabalho foi o de encontrar alternativas aos combustíveis fósseis, pautando-se por soluções inofensivas para o meio ambiente e sustentáveis. Assim, o trabalho está dividido em quatro etapas: 1) caraterização química e biológica da drêche; 2) pré-tratamento ácido e hidrólise enzimática para primeiramente quebrar as moléculas de lenhina que envolvem os polímeros de celulose e hemicelulose e em seguida romper as ligações poliméricas destas macromoléculas por ação enzimática e transforma-las em açúcares simples, respetivamente, obtendo-se então a glucose, a maltose, a xilose e a arabinose; e, por último, 3) otimização da etapa de fermentação da glucose, maltose e das pentoses que constitui a condição essencial para se chegar à síntese do bioetanol de um modo eficiente e sustentável e 4) a recuperação do bioetanol produzido por destilação fracionada. A quantificação dos açúcares libertados no processo foi feita recorrendo a análises por cromatografia líquida de alta eficiência (HPLC). Neste estudo foram identificados e quantificados cinco açúcares: Arabinose, Glucose, Maltose, Ribose e Xilose. Na etapa de pré-tratamento e hidrólise enzimática foram usados os ácidos clorídrico (HCl) e nítrico (HNO3) com a concentração de 1% (m/m), e as enzimas Glucanex 100g e Ultraflo L. Foram testadas seis condições de pré-tratamento e hidrólise enzimática, alterando os parâmetros tempo de contacto e razão enzimas/massa de drêche, respetivamente, e mantendo a temperatura (50 ºC), velocidade de agitação (75 rpm) e concentração dos ácidos (1% (m/m)). No processamento de 25 g de drêche seca com 0,5 g de Glucanex, 0,5 mL de Ultraflo e um tempo de reação de 60 minutos para as enzimas foi obtida uma eficiência de 15%, em hidrolisado com 6% da celulose. Realizou-se a fermentação do hidrolisado resultante do pré-tratamento ácido e hidrólise enzimática de drêche cervejeira e de meios sintéticos preparados com os açúcares puros, usando as duas estirpes selecionadas para este estudo: Pichia stipitis NCYC 1541 e Kluyveromyces marxianus NYCY 2791. As eficiências de fermentação dos açúcares nos meios sintéticos foram superiores a 80% para ambas as leveduras. No entanto, as eficiências de fermentação do hidrolisado da drêche foram de 45,10% pela Pichia stipitis e de 36,58 para Kluyveromyces marxianus, para um tempo de fermentação de 72 horas e à temperatura de 30 °C. O rendimento teórico em álcool no hidrolisado da drêche é de 0,27 g/g, três vezes maior do que o real (0,0856 g/g), para Pichia stipitis e de 0,19 g/g seis vezes maior do que o real (0,0308 g/g), para a Kluyveromyces marxianus.