Development of an integrated process of membrane filtration for harvesting microalgae and recovery of high-value compounds

The work presented in this PhD thesis aims at developing an integrated method for harvesting Dunaliella salina, both in the non-carotenogenic and in the carotenoid-rich phases, using membrane processes and centrifuges. Additionally, the ultimate goal is the recovery of high-value compounds for application in the food, cosmetic and pharmaceutical industries. Dunaliella salina is a halotolerant green microalga, which under low nitrogen and high salinity conditions, produces carotenoids. This microalga is very fragile due to lack of a rigid cell wall and, consequently, can be easily ruptured when an excessive shear stress is applied. Firstly, the pre-concentration of Dunaliella salina by membrane filtration prior to a final harvesting step by centrifugation was performed. The aim of the integrated harvesting process was to minimise the overall energy expenditure and reduce capital costs, while assuring a minimal loss of cell integrity. For the harvesting experiments the main parameters were optimised, namely: cross-flow velocity (vcross-flow), transmembrane pressure (TMP), membrane molecular weight cut-off (MWCO), backflush protocol and permeate volumetric flux (JV). The harvesting of non-carotenogenic Dunaliella salina by ultrafiltration, under controlled transmembrane pressure, allowed a final concentration factor of 5.9 and an average permeate flux of 31 L/(m2.h). The harvesting of carotenoid-rich Dunaliella salina, under controlled permeate flux, reached a concentration factor of 10, at a permeate volumetric flux of 21 L/(m2.h). The integrated process led to a reduction of Total Cost of Ownership (TCO) and energy consumption of 70% and 76%, respectively, when comparing with harvesting only with centrifuges (one-step approach). Additionally, several oxidation processes were studied for treatment of the permeate recovered, after membrane harvesting, in order to assess its recycle as cultivation medium for Dunaliella salina. The permeate was treated either by ozonation or by UV radiation, and the different types of permeate were tested as cultivation media. The results obtained indicate that the permeate treated by UV with addition of H2O2 was best suited for the growth of carotenoid-rich Dunaliella salina. Nevertheless, the use of untreated permeate seems a reasonable alternative, considering that it might be the most cost efficient solution. Finally, a Dunaliella salina biorefinery process was developed for the recovery and fractionation of added-value compounds, with a particular focus on the recovery of polar lipids. This work combined extraction with REACH solvents, a saponification reaction and organic solvent nanofiltration processes to obtain distinct fractions of compounds. Overall, high recoveries were obtained (85% of carotenoids, 86% of glycerol, 94% of polar lipids and 95% of proteins), as well as fractions with high product enrichment in polar lipids and in glycerol

Characterization of beet necrotic yellow vein furovirus from Spanish sugar beets

Rhizomania is a viral disease, caused by beet necrotic yellow vein furovirus (BNYVV), which was detected in Spanish sugar beets in 1988, it being focused on the Castilla y León region. BNYVV has five RNA fragments with specific functions, and the different composition and proportion of RNA in the virions allow their separation and the characterization of their activities during the development of the disease. Thirty–six samples of sugar beet rootlets and frozen pulps from three different sugar beet zones of Castilla y León were analyzed by DAS-ELISA and Immunocapture-Reverse Transcription-Polymerase Chain Reaction (IC-RT-PCR) using specific primers. The identity of the cDNA products was confirmed by nested- PCR and restriction fragment length polymorphism (RFLP). The uniformity of the patterns obtained by RFLP analyses with nine endonucleases showed the existence of a unique strain of BNYVV in 80,000 Ha of crop surface which could be explained by a recent arrival of the rhizomania disease to this region. The isolates studied were more similar to type A, which has been previously described in BNYVV, but a nonexpected cleavage site for this molecular group was observed with endonuclease Hinc II on the RNA-2 IC-RT-PCR product (nt 2133–3293) in the thirty–six Spanish samples and also in a North American strain taken as reference. The use of frozen pulps obtained as a previous step to the industrial extraction of sugar avoids problems due to erratic distribution of the virus in the roots, provides repetitive results for a particular sample, and facilitates epidemiological and distributional studies on rhizomania disease

Evolutionary divergence in the bioactive jasmonate in land plants

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 21-09-2017Esta tesis tiene embargado el acceso al texto completo hasta el 21-03-2019Los jasmonatos son fitohormonas implicadas en activación de defensas y en procesos de desarrollo. En eudicotiledóneas la hormona activa, JA-Ile, induce la interacción entre los dos componentes del co-receptor: la F-box COI1 y uno de los represores JAZ. La ruta de señalización del jasmonato se ha estudiado fundamentalmente en la planta modelo Arabidopsis thaliana, pero apenas se ha caracterizado en otros grupos de plantas. El análisis de genomas disponibles de diversos linajes vegetales sugiere que todos los componentes de la ruta de señalización de jasmonatos ya estaban presentes en el ancestro común de las plantas terrestres. Los briófitos actuales son el grupo más primitivo de este tipo de plantas, y dentro de ellos, las hepáticas se consideran el linaje hermano al resto de plantas terrestres. En este trabajo hemos utilizado como planta modelo la hepática Marchantia polymorpha para estudiar la evolución y la conservación funcional de la ruta del jasmonato. Además de su posición evolutiva privilegiada, M. polymorpha tiene una redundancia génica extraordinariamente baja, lo que facilita el análisis funcional de familias multigénicas en plantas superiores. Nuestros resultados demuestran que la percepción de jasmonatos y su maquinaria de señalización están conservados en plantas terrestres, pero la hormona es diferente en briófitos y plantas vasculares. Hemos identificado el dinor-OPDA como la hormona activa en briófitos y hemos demostrado que un solo aminoácido en el receptor COI1 determina la especificidad de ligando. En conjunto, nuestros resultados explican los acontecimientos evolutivos que condujeron a la aparición del JA-Ile y COI1 en plantas vasculares a partir de sus ortólogos ancestrales. Además, la caracterización del co-receptor COI1/JAZ en plantas terrestres nos ha permitido desarrollar un antagonista específico de la percepción de JA-Ile con potencial biotecnológicoJasmonates are phytohormones involved in defence and developmental processes such as fertility. In eudicots, the active hormone JA-Ile induces the interaction between the two members of the coreceptor: the F-box COI1 and one of the JAZ repressors. The jasmonate signalling pathway has been mainly studied in the model plant Arabidopsis thaliana, but little is known about this pathway in other plant lineages. Sequence analyses of available algae and land plants genomes showed that all the signalling components of the JA-Ile pathway might have been already present in the common ancestor of all land plants. Extant bryophytes are the most basal group of land plants, and among them, liverworts are considered the sister lineage to all other land plants. In this work, we have used the model liverwort Marchantia polymorpha to study the evolution and functional conservation of the jasmonate pathway. Besides its key evolutionary position, M. polymorpha shows an extraordinary low gene redundancy that facilitates the study of large gene families. Our results demonstrate that the jasmonate perception and signalling machinery are conserved in land plants but the hormone is different in bryophytes and vascular plants. We have identified dinor-OPDA as the active hormone in bryophytes as well as the residue that determines the ligand specificity in COI1. Taken together our results explain the evolutionary events that lead to the appearance of JA-Ile and COI1 in vascular plants from their ancestral counterparts. In addition, the characterization of the COI1/JAZ co-receptor in land plants has allowed us to develop a specific antagonist of JA-Ile perception with biotechnological potential

Rentabilidade dos Clientes de uma Seguradora Automóvel

O mundo está em constante evolução e as alterações daí resultantes são notórias de ano para ano. O comércio é uma das áreas onde tais mudanças são claramente visíveis. Foram criadas novas necessidades de consumo, entre as quais a aquisição de viatura própria e, com ela, a subscrição do obrigatório seguro automóvel. Outro elemento que foi inserido no quotidiano da população portuguesa foi a aceitação e adesão às novas tecnologias, o que veio alterar a produção e os hábitos da sociedade. O presente estudo tem como objectivo analisar a rentabilidade dos clientes de uma seguradora, cujo principal ramo de actividade é o seguro automóvel. Para que a seguradora prospere no mercado é necessário o seu reconhecimento por parte dos consumidores e, sobretudo, que o seu negócio seja rentável e bastante competitivo face ao restante mercado. Estas condições só se verificam se forem geradas mais receitas que despesas, dando ao negócio alguma estabilidade económica. A análise em causa permitirá conhecer as características dos clientes mais e menos rentáveis para a empresa. É de extrema importância que uma seguradora conheça o perfil dos seus clientes, pois são estes que geram receita, mas são naturalmente quem também pode originar perdas elevadas, consumindo os prémios e, por vezes, as reservas de segurança. Assim, compreender qual o potencial dos clientes gerarem mais ou menos valias é essencial para analisar possíveis falhas no desenho dos produtos, no cálculo e construção de provisões para os sinistros, na determinação dos prémios ou sistema de bonus‐malus (tarifação a posteriori), ou no processo de subscrição. Permitindo à seguradora uma melhoria na qualidade da tomada de decisão, pois terá bases mais sólidas na análise e gestão do risco, salvaguardando a estabilidade financeira e protegendo os interesses dos seus segurados e accionistas. Uma das formas utilizadas para estudar a rentabilidade de clientes é com recurso a técnicas estatísticas adequadas, nomeadamente recorrendo a Modelos Lineares Generalizados, que permitem analisar a relação entre variáveis e a influência das mesmas sobre outra variável. No âmbito dos seguros a utilização de MLG permitiu às seguradoras, por exemplo, perceber que características do condutor e do veículo que mais afectam os níveis de sinistralidade, tanto em número como em custos de sinistros, que são questões fundamentais no âmbito da tarifação

Estudio estratigráfico y de correspondencia de los parámetros decorativos de la escalera de la Santa Cueva de Cádiz. Definición del proyecto de intervención

El templo de la Santa Cueva situado en la calle Rosario es un conjunto histórico artístico compuesto de una capilla baja o subterránea, dedicada a la meditación de la Pasión de Cristo, y de otra alta, u oratorio, consagrado al Santísimo Sacramento. Su construcción se llevó a cabo en la segunda mitad del siglo XVIII en estilo clasicista o neoclásico. El día 31 de marzo de 1796 se bendijo e inauguró el oratorio, culminándose la obra del conjunto

O impacto da Revolução Francesa na historiografia portuguesa oitocentista: uma perspectiva comparada

A Revolução Francesa e os seus princípios influenciaram e modificaram o pensamento e a mentalidade da sociedade portuguesa de Oitocentos. A Revolução e os seus efeitos, quer positivos quer negativos, ficaram inevitavelmente na memória e no coração de muitos indivíduos dessa época. O tempo e a história, enquanto fios condutores da memória, auxiliaram os historiadores portugueses oitocentistas a escreverem “histórias” e “memórias” sobre a influência da Revolução Francesa no seu país: Portugal. Deste modo, a dissertação de mestrado pretende, a partir das várias gerações de autores oitocentistas, compreender através de uma história comparada como é que a vida pessoal, o percurso escolar e a ideologia política influenciaram o pensamento e a visão do historiador sobre o impacto da Revolução Francesa em Portugal, nos séculos XVIII e XIX. Paralelamente pretende-se, com base nestas linhas de interpretação, perceber como é que estas perspectivas possibilitaram a construção de memórias diferentes e contrárias da Revolução Francesa na historiografia portuguesa do século XIX.The French Revolution and its principles influenced and changed the thought and the mentality of the nineteenth century portuguese society. The Revolution and its effects, either positive or negative, necessarily stayed in the memory and in the hearth of many individuals of that epoch. As memory conducting wire, time and history, helped the nineteenth century portuguese historians to write “stories” and “memories” about the influence of the French Revolution on their country: Portugal. From the diverse historian’s generation, the present dissertation intends to understand through a comparative history how the personal life, the scholar route and the policy ideology influenced the historian thinking and view about the impact of the French Revolution in Portugal, on the eighteenth and nineteenth century’s. Based on those interpretation lines it also seeks to realize in what way these perspectives enabled the construction of different and contrary memories of the French Revolution on the nineteenth century portuguese historiography

Evaluation of the potential of agro-industrial waste-based composts to control Botrytis gray mold and soilborne fungal diseases in lettuce

Composts are widely used in horticulture as organic amendments to improve the properties of soils. Composts have also been reported to enhance the disease suppressive potential of soils and, therefore, could be used as a strategy for managing plant diseases. The aim of this study was to test the ability of soils amended with four different agro-industrial waste-based composts (chestnut peels and shells, spent coffee grounds, grape marc, and olive leaves) to inhibit the growth and activity of Botrytis cinerea and several soilborne pathogens. First, the capacity of aqueous compost extracts to inhibit the growth of Botrytis cinerea and five soilborne fungi was evaluated in vitro using a broth macrodilution method. Second, lettuce plants were grown on soils amended with composts and inoculated either with B. cinerea or the soilborne fungus Fusarium oxysporum Schlechtendahl isolated from lamb’s lettuce. The determination of minimal inhibitory concentrations indicated that none of the composts inhibited the mycelium growth of the selected fungal pathogens. However, the pathogens did not cause any damage on plants grown on the chestnut- and olive-based composts. Lettuce yields were also highest for plants grown with composts made from chestnut and olive, irrespective of the amount of compost incorporated into soils (5% or 10%, weight basis). The grape-based compost also exhibited a fertilization effect, although the effect was associated with increased Fusarium wilt severity. Both N immobilization and symbiosis with the compost’s microflora were used to explain the pathogenicity of F. oxysporum Schlechtendahl in response to amendment with composts made from grape and coffee wastes. The beneficial effects of the chestnut- and olive-based composts reported in this study could be exploited in strategies aimed at reducing reliance on synthetic pesticides for the control of fungi in lettuce cultivation.This work was supported by European Investment Funds (FEDER/COMPETE/POCIOperational Competitiveness and Internationalization Program) under the project POCI-0145-FEDER006958 and by national funds provided by FCT—Portuguese Foundation for Science and Technology, under the projects PTDC/AGR-AAM/102006/2008, SFRH/BD/81473/2011 and UIDB/04033/2020

O impacto do isolamento em idosos institucionalizados durante a pandemia em Portugal

Dissertação de mestrado, Psicologia (Área de Especialização em Psicologia Clínica e da Saúde - Psicologia Clínica Cognitivo-Comportamental e Integrativa), Universidade de Lisboa, Faculdade de Psicologia, 2021O envelhecimento representa, por si só, um aspeto de enorme vulnerabilidade e preocupação comum ao Ser Humano. Num contexto pandémico, foram tomadas medidas necessárias para a prevenção do contágio do vírus covid-19, sendo uma delas o isolamento. Para os idosos que já se encontram institucionalizados, e a quem foram limitadas as visitas e contactos presenciais, surge a necessidade de compreender em que medida a população referida foi afetada. Pelos motivos referidos, a presente investigação tem como principal objetivo explorar e averiguar as dimensões em que os idosos institucionalizados, mais especificamente no Alentejo, foram afetados. Com esse propósito em mente, foi utilizado o questionário de rastreio MMSE para averiguar a capacidade cognitiva dos idosos, o BSI como medida objetiva do seu bem-estar, e um guião de entrevista para direcionar uma entrevista semiestruturada, com foco em várias dimensões e áreas possivelmente afetadas. Realizou-se uma análise qualitativa dos resultados obtidos através do software Nvivo e respetiva codificação e análise temática. Os resultados demonstraram que não houve um impacto significativo, sendo que a maioria dos idosos reportou não ter sentido diferenças resultantes da pandemia. Isto pode ter-se devido à enorme adesão a aspetos de socialização e de realização de atividades nas instituições, o que expressa uma boa adaptação de ambas as partes aos desafios da pandemia.Aging represents, by itself, an aspect of enormous vulnerability and common concern to Human Beings. In a pandemic context, necessary measures were taken to prevent the spread of the covid-19 virus, one of which was isolation. For the elderly, who were already institutionalized, and to whom visits and face-to-face contacts were limited, there was a need to understand to what extent the referred population was affected. For these reasons, the main goal of this investigation is to explore and investigate the dimensions in which institutionalized elderly people, more specifically in Alentejo, Portugal, were affected. With this purpose in mind, the MMSE screening questionnaire was used to assess the cognitive ability of the elderly, the BSI as an objective measure of their well-being, and an interview guide to direct a semi-structured interview, focusing on various dimensions and areas possibly affected. A qualitative analysis of the results obtained through the Nvivo software and respective coding and thematic analysis was carried out. The results showed that there was no impact, with the majority of the elderly reporting not having a significant sense of the pandemic. This may have been due to the huge adherence to aspects of socialization and carrying out activities in institutions, which shows a good adaptation of both parties to the challenges of the pandemic