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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Srovnání metabolické aktivity a potenciálního využití mikrořas a pigmentotvorných kvasinek / A comparison of metabolic activity and use of microalgae and pigment-formed yeasts

Szotkowski, Martin January 2016 (has links)
Carotenoids are natural pigments occurring in plants and many microorganisms, such as algae, yeast and bacteria. They represent the most common group of antioxidants with significant biological effect. Lipids are an essential component of all living organisms. They are the source and the reservoir of energy for organisms, which can also be used in the petrochemical industry for the production of biofuels. This thesis deals with the production properties of carotenoids and lipids by selected strains of yeasts, algae, and canobacteria, in order to apply the acquired knowledge and find cheap suitable alternatives for microbial biotechnological production of these metabolites using waste substrates. Carotenoids, coenzyme Q, and ergosterol in cells were determined by liquid chromatography. The lipid content and fatty acid profile was analyzed by gas chromatography. Cell morphology and localization of selected metabolites were analyzed by fluorescence lifetime imaging microscopy. In this work yeast genera Sporobolomyces, Cystofilobasidium and Rhodotorula were used. As the representatives of the algae and cyanobacteria strains of Desmodesmus, Cyanothece, Chlamydomonas, Synechoccocus and Chlorella strains were studied. In the overall comparison, the yeast strains were more productive than algae and cyanobacteria. The highest carotenoid production was found in S. pararoseus, C. capitatum and R. mucilaginosa cells, while the highest lipid yield was observed in strains of C. infirmominiatum and S. metaroseus.
12

Identificação dos compostos de degradação de carotenoides e avaliação do impacto sobre a cor e aroma em sistemas-modelo simuladores de suco de caju / Identification of degradation compounds of carotenoids and evaluation of the impact on the color in cashew apple juice model-systems

Zepka, Leila Queiroz 11 September 2018 (has links)
Orientador: Adriana Zerlotti Mercadante / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-09-11T21:13:51Z (GMT). No. of bitstreams: 1 Zepka_LeilaQueiroz_D.pdf: 2815017 bytes, checksum: 8abad3ae0da0bc1b940e100078096285 (MD5) Previous issue date: 2009 / Resumo: contém no texto completo. / Abstract: contém no texto completo. / Doutorado / Doutor em Ciência de Alimentos
13

Caracteriza??o de m?is brasileiros: f?sico-qu?mica, perfil de subst?ncias polares, atividade antioxidante e quimiometria / Characterization of brazilian honeys: physico-chemical, polar substances profile, antioxidant activity and chemometrics

SALGUEIRO, Fernanda Barbosa 09 March 2012 (has links)
CAPES / Honey is generally known for its therapeutic value and the determination of its main floral source allows the certification to the consumer the properties related to its origin. Thus, the aim of this work was to evaluate the quality and characterize eleven honeys from Apis mellifera from the state of Rio de Janeiro according to physico-chemical parameters, to phenolics profile, to the antioxidant activity and also through the use of chemonetric analysis applied to 1H NMR data and HPLC-DAD. Two samples of assa peixe, six samples of cambara and three samples of morr?o-de-candeia honeys from diferente regions of Rio de Janeiro were analyzed. The physico-chemical parameters determined were: HMF content and color through a spectrophotometric method, free acidity and pH. The content of free amminoacids was also determined through the c?dmium-ninhydrine together with total proteins via the Bradford method. The antioxidant ability of honeys and their extracts was qualitatively determined through the total phenolics content using the Folin-Denis method. Total flavonoids were determined by the complexation method with aluminium chloride. The quantitative antioxidant activity of honeys was determined by the trapping of the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical, by trapping of the ABTS.+ radical and also by the iron reduction method (FRAP). The identification and quantitation of polyphenols in the extracts were done by HPLC-PDA. The use of multivariate analysis for the 1H NMR data and HPLC enabled the distinction of the honeys analyzed in this work. Thus, the use of 1H NMR and HPLC data combined with multivariate analysis may be employed as a new strategy for the fast and non-destructive typification of Brazilian honeys. / No mercado, m?is s?o conhecidos pelo seu poder terap?utico e a designa??o de sua principal fonte floral permite atestar ao consumidor as propriedades de sua origem. Assim, o objetivo deste trabalho foi avaliar a qualidade e caracterizar onze m?is de Apis mellifera provenientes do Estado do Rio de Janeiro, por meio de par?metros f?sico-qu?micos, do perfil de subst?ncias fen?licas, de seus potenciais antioxidantes, al?m de usar m?todos quimiom?tricos aplicados aos dados de RMN de 1H e CLAE-DAD. Para tanto, utilizou-se duas amostras de mel de assa peixe, seis de cambar? e tr?s de morr?o de candeia de diferentes munic?pios do Rio de Janeiro. Os par?metros f?sico-qu?micos avaliados foram: teor de HMF e a cor utilizando m?todo espectrofotom?trico, acidez livre e pH. Al?m dessas determina??es, o conte?do de amino?cidos livre foi avaliado pelo m?todo de c?dmio-ninidrina, e prote?nas totais pelo m?todo de Bradford. A capacidade antioxidante dos m?is e de seus extratos foi avaliada qualitativamente atrav?s do conte?do de fen?licos total pelo m?todo de Folin-Denis, e de flavon?ides total pelo m?todo de complexa??o com cloreto de alum?nio. A quantifica??o do potencial antioxidante foi realizada pela captura do radical 2,2-difenil-1-picril-hidrazil (DPPH), captura do radical livre ABTS.+, al?m do m?todo de redu??o do ?on f?rrico (FRAP). A identifica??o e quantifica??o das subst?ncias polifen?licas dos extratos foi feita por cromatografia l?quida de alta efici?ncia com detector de arranjo de diodos (CLAE-DAD). A aplica??o da an?lise multivariada aos dados de RMN de H e de CLAE-DAD distinguiu os m?is de assa peixe, cambar? e morr?o de candeia produzidos no Estado do Rio de Janeiro. Assim, o uso de RMN de 1H e CLAE-DAD combinado com a quimiometria pode ser uma nova estrat?gia para tipifica??o de m?is brasileiros de forma r?pida e n?o destrutiva.
14

Determinação do grau de pureza de amostra de crack apreendidas no Estado da Paraíba por RMNq-1H e CLAE-DAD

Costa, Rony Anderson Rezende 10 February 2012 (has links)
Made available in DSpace on 2015-05-14T12:59:32Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3288068 bytes, checksum: 0a30af77d23fdb0cbfe338a83f189634 (MD5) Previous issue date: 2012-02-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Population´s commonsense regards crack cocaine as an impure byproduct of cocaine. In Brazil, the cocaine levels in crack samples or the profiling of its adulterants is not a mandatory analysis of official forensic laboratories. The state of Paraiba has shown a marked increase in the number of analyses done on crack cocaine samples seized by the police forces between 2007 and 2010, rising from 250 to 575 analyses. On the other hand, there is no literature data on the concentration of cocaine on these samples. The present study aimed at developing and validating a method based on quantitative hydrogen nuclear magnetic resonance spectroscopy (1H-qNMR) to determine cocaine in crack cocaine samples seized within the state of Paraiba. 1H-qNMR is a primary analytical method and can become accurate and precise when certain acquisition and processing parameters are properly set. The 1H-qNMR method was compared to a high performance liquid chromatography method with photodiode array detection (HPLC-PDA). The results from both methods allowed us to determine that the average concentration of cocaine in the samples was higher than 70%. The average concentration determined by the 1H-qNMR method was 71.9%, with samples ranging from 5.2 to 89.1%. The results from the HPLC-PDA method were slightly higher, with an average figure of 74.4% and samples ranging from 4.9 to 93.8%. The best correlation between HPLC-PDA and 1H-qNMR data was obtained when integration from region 7 of the spectrum was used (singlet signal at 3.6 ppm from the methyl protons of the ester function) yielding a Pearson´s correlation coefficient of 0.83. Precision and accuracy of the 1H-qNMR method was sensitive to several acquisition and processing parameters that need to be optimized. The HPLC-PDA method developed proved to be fast, accurate and precise for the quantification of cocaine in 47 samples of seized crack cocaine. In addition, the analysis of crack cocaine samples by gas chromatography coupled to mass spectrometry (GC/MS) revealed that the main adulterant present in the samples was phenacetin, a result that was confirmed by the 1H-NMR data. / O senso comum da população tem o crack como um subproduto impuro da cocaína. No Brasil, a análise do teor de cocaína em amostras de crack ou a pesquisa de adulterantes adicionados não constitui rotina nos laboratórios oficiais das perícias forenses. O estado da Paraíba apresentou um crescente número de análises em amostras de crack apreendidas pelas forças policiais entre os anos de 2007 e 2010, passando de 250 para 575 exames. Por outro lado, não existem na literatura dados sobre o teor de cocaína nestas amostras. O presente trabalho teve como objetivo desenvolver uma metodologia baseada no uso da espectroscopia de ressonância magnética nuclear quantitativa de hidrogênio (RMNq-1H) para avaliar o grau de pureza de amostras de crack apreendidas no estado da Paraíba. A RMNq-1H é um método analítico primário e pode tornar-se exata e precisa quando satisfeitos parâmetros de aquisição e processamento dos dados. O método de RMNq-1H foi comparado à metodologia desenvolvida e validada baseada em cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodos (CLAE-DAD). Os resultados das duas metodologias permitiram determinar que o teor médio de cocaína nas amostras foi superior a 70%. O teor médio de cocaína determinado pelo método de RMNq-1H foi de 71,9%, com amostras variando entre 5,2 a 89,1%. Os resultados do método de CLAE-DAD foram ligeiramente superiores, onde o teor médio de todas as amostras foi de 74,4%, com amostras variando entre 4,9 e 93,8% de cocaína. A melhor correlação obtida entre os resultados de CLAE-DAD e RMNq-1H foi aquela que utilizou a região 7 (singleto em 3,6 ppm correspondente a metila da função éster), com coeficiente de correlação de Pearson de 0,83. A precisão e exatidão da RMNq-1H mostrou-se sujeita a diversos parâmetros de aquisição que precisam ser otimizados. Por sua vez a metodologia por CLAE-DAD mostrou-se rápida, exata e precisa para quantificação de cocaína em 47 amostras de crack analisadas. Além disso, as amostras foram submetidas a análise por cromatografia a gás acoplada a espectrometria de massas (CG/EM), mostrando que o principal adulterante nas amostras foi a fenacetina, dado confirmado por RMN-1H.
15

Produkce vybraných metabolitů pomocí kvasinek a řas kultivovaných ve stresových podmínkách / Production of selected metabolites by yeasts and algae cultivated under stress conditions

Mariničová, Veronika January 2019 (has links)
The presented work was focused on the comparison between the production of selected metabolites by carotenogenic yeasts and microalgae cultivated under conditions of external stress. The main metabolites of interest were carotenoids, further lipophilic substances and lipids. Biotechnological overproduction of these metabolites could serve as a source of potentially beneficial substances not only for the pharmaceutical, cosmetic and food industries, but also for the production of third generation biofuels. Recently, there has been a growing interest in biofuels primarily from microalgae, which have a high potential in biofuel production and seem to be a promising source. The theoretical part deals with the description of individual genera of carotenogenic yeasts, microalgae, cyanobacteria, chemical composition of produced metabolites and brief biosynthesis. In addition, individual methods for analyzing the production of the metabolites of interest were described. The experimental part is focused on the comparison of production of carotenoids, coenzyme Q, ergosterols (phytosterols) and lipids by yeasts, microalgae and cyanobacteria. As a source of external stress, temperature, salt and light stress were chosen. The strains of Rhodotorula glutinis, Rhodotorula mucilaginosa, Sporidiobolus pararoseus and Cystofilobasidium macerans were studied from the yeast strains. Microalgae and cyanobacteria were Scenedesmus obliqus, Scenedesmus dimorphus, Chlorella sorokiniana, Chlorella saccharophila, Botryococcus brauni, Synechococcus nidulans and Arthrospira maxima. The yeast and algal strains were optimized for growth, carotenoid and lipid production. Applied salt stress showed a significant liquidation effect on algal and cyanobacterial strains. The thesis also monitored the biological stress, so-called co-cultivation of microalgae and yeasts. Further experiments will be the subject of future work.
16

Optimalizace extrakce pigmentů z buněk kvasinek a řas / Optimization of extraction of pigments from yeast and algae cells

Šimanský, Samuel January 2020 (has links)
The presented diploma thesis deals with the extraction and storage stability of lipophilic pigments produced by selected strains of yeasts and algae. In this thesis, there was studied the influence of the selected solvents on the efficiency of extraction, as well as the effect of ambient temperature on the stability of the pigments during storage. The work is divided into two main parts, theoretical and practical part. In the theoretical part knowledge about algae, yeasts and their cultivation parameters is summarized. Furthermore, some information regarding the selected lipid metabolites, their properties and possibilities of application in various branches of industry is mentioned. The practical part deals with the preparation of extracts and stability tests. Extracts were prepared from selected biomass samples in solvents suitable for applications in food industry or cosmetics (ethanol and hexane). Subsequently, the long-term stability tests lasting 4 months and short-term stability tests lasting a total of 28 days were performed on these extracts. The pigments were determined by HPLC and spectrophotometrically, the fatty acid content was determined by GC. For the extraction of pigments from biomass, in the most cases ethanol appears to be the optimal solvent. However, for lipid extraction from biomass, hexane appears to be the optimal solvent for a significant number of samples. In most samples, storage in the freezer showed the most favourable effect on pigment stability, but some samples showed comparable stability even when stored in the refrigerator.

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