abstract: The origin of Life on Earth is the greatest unsolved mystery in the history of science. In spite of progress in almost every scientific endeavor, we still have no clear theory, model, or framework to understand the processes that led to the emergence of life on Earth. Understanding such a processes would provide key insights into astrobiology, planetary science, geochemistry, evolutionary biology, physics, and philosophy. To date, most research on the origin of life has focused on characterizing and synthesizing the molecular building blocks of living systems. This bottom-up approach assumes that living systems are characterized by their component parts, however many of the essential features of life are system level properties which only manifest in the collective behavior of many components. In order to make progress towards solving the origin of life new modeling techniques are needed. In this dissertation I review historical approaches to modeling the origin of life. I proceed to elaborate on new approaches to understanding biology that are derived from statistical physics and prioritize the collective properties of living systems rather than the component parts. In order to study these collective properties of living systems, I develop computational models of chemical systems. Using these computational models I characterize several system level processes which have important implications for understanding the origin of life on Earth. First, I investigate a model of molecular replicators and demonstrate the existence of a phase transition which occurs dynamically in replicating systems. I characterize the properties of the phase transition and argue that living systems can be understood as a non-equilibrium state of matter with unique dynamical properties. Then I develop a model of molecular assembly based on a ribonucleic acid (RNA) system, which has been characterized in laboratory experiments. Using this model I demonstrate how the energetic properties of hydrogen bonding dictate the population level dynamics of that RNA system. Finally I return to a model of replication in which replicators are strongly coupled to their environment. I demonstrate that this dynamic coupling results in qualitatively different evolutionary dynamics than those expected in static environments. A key difference is that when environmental coupling is included, evolutionary processes do not select a single replicating species but rather a dynamically stable community which consists of many species. Finally, I conclude with a discussion of how these computational models can inform future research on the origins of life. / Dissertation/Thesis / Doctoral Dissertation Physics 2018

Duas questões fundamentais no estudo da evolução pré-biótica (origem da vida) referem-se à estabilidade dos primeiros organismos ou replicadores e à possibilidade do surgimento de organismos complexos através de mutações de organismos mais simples. Esses problemas têm sido tratados quase que exclusivamente no contexto determinístico da cinética química de meios perfeitamente homogêneos, que é equivalente à formulação de campo médio da física estatística. Nesta tese, abordamos essas questões utilizando modelos de replicadores na rede que evoluem no tempo de forma síncrona (autômato celular), dando ênfase ao caso limite em que os replicadores são mantidos fixos nos sítios da rede (processo de contato). Encontramos dois regimes estacionários bem definidos: o regime absorvente ou vácuo e o regime ativo caracterizados, respectivamente, pela ausência e presença de replicadores na rede. Esses regimes são separados por transições de fase cuja natureza depende do mecanismo de reprodução dos replicadores. Essas transições são investigadas de maneira sistemática utilizando-se a técnica de espalhamento de Grassberger e de La Torre em que a evolução temporal de uma pequena colônia de replicadores colocada no centro de uma rede infinita vazia \\\'e acompanhada. Em particular, através do cálculo de expoentes críticos dinâmicos mostramos que, as transições contínuas observadas, pertencem à classe de universalidade da percolação direcionada. Complementamos esse estudo investigando a probabilidade de que uma pequena colônia de replicadores invada uma população de replicadores residentes de outra espécie. Ao contrário dos resultados de campo médio, mostramos que no caso de processos de contato, replicadores mais complexos (por exemplo, assexuados) podem invadir uma população estabelecida de replicadores mais simples (por exemplo, assexuados). Em concordância com os resultados de campo médio, encontramos que nunca ocorre coexistência entre replicadores distintos no equilíbrio. Finalmente, utilizando a técnica de espalhamento mencionada, investigamos de forma sistemática um modelo para formação de úlceras devido à infecção do vírus da herpes (HSV-I) no tecido epitelial da córnea. O modelo considerado tenta explicar as diferentes formas de úlceras-dendríticas e amebóides-resultantes desta infecção como um resultado natural do espalhamento do vírus num tecido epitelial formado por células com diferentes graus de susceptibilidade à infecção. Em particular, mostramos que a transição de fase separando os regimes caracterizados pelas diferentes morfologias pertence à classe de universalidade da percolação ordinária. / Two fundamental questions in the study of prebiotic evolution (origin of life) are concerned to the requisites for the persistence of small colonies of self-replicating molecules (replicators) and to the possibility that complex organisms evolve from simpler organisms as a result of mutations. These issues have been studied mainly in the chemical kinetics formulation of well-mixed medium, which is similar to the mean-field limit of statistical physics. In this work, we address these issues using a cellular automaton formulation, in which the replicators are kept fix in the lattice sites (contact process). In the stationary regime, we find that the system can be characterized by the presence (active phase) and the absence (empty phase) of replicators in the lattice. The detailed study of the phase transitions separating those two phases is carried out using the spreading analysis of Grassberger and de La Torre, in which one concentrates on the spreading behavior of a few active cells in the center of an otherwise empty infinite lattice. The nature of the phase transition, whether continuous or discontinuous, depends on the mechanisms of replication. In particular, in the case that the phase transition is continuous, we find that it is in the universality class of the directed percolation. Complementing this study, we irivestigate the possibility that a small colony of replicators invade a settled population of replicators of another species. Contrary to the results of the mean-field limit, we show that in the contact process limit, complex replicators (such as sexual reproducing ones) have a nonvanishing probability to invade a settled population of simpler replicators (such as asexual reproducing ones). In agreement with the mean-field results, we find that two different species of replicators can never coexist in an equilibrium situation. Finally, using the spreading analysis mentioned before we study the critical properties of a cellular automaton model proposed to describe the spreading of infection of the Herpes Simplex Virus (HSV-I) in the corneal tissue. The model takes into account different cell susceptibilities to the viral infection, as suggested by experimental findings, in order to explain the different shapes of the ulcers - dentritic and amoeboid - that result from the infection. We show that the phase transition separating the regimes where one of the shapes dominates is in the universality class of the ordinary percolation.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os alimentos funcionais vÃm conquistando espaÃo como uma boa alternativa na prevenÃÃo de doenÃas, sendo a maioria destes encontrados no mercado na forma de produtos lÃcteos, inviabilizando o consumo por indivÃduos intolerantes à lactose. Dentro deste contexto, o presente trabalho objetivou a elaboraÃÃo de suco de tangerina contendo oligossacarÃdeos prÃ-bioticos e desidrataÃÃo do mesmo em leito de jorro. A sÃntese dos oligossacarÃdeos foi realizada seguindo um planejamento experimental utilizando a enzima dextrana-sacarase, obtida a partir do Leuconostoc mesenteroidesB512F, sendo selecionado o ensaio que apresentou uma concentraÃÃo de 61,28 g/L de oligossacarÃdeos. O processo de secagem por leito de jorro foi otimizado mediante a aplicaÃÃo de dois planejamentos sendo o primeiro um planejamento fatorial fracionado e o segundo um planejamento composto central. Para o primeiro planejamento foram consideradas variÃveis independentes a temperatura, concentraÃÃo de maltodextrina, massa de inerte e vazÃo de alimentaÃÃo; e as variÃveis resposta o rendimento do processo, atividade de Ãgua do pà obtido, tempo de reidrataÃÃo e umidade. O segundo planejamento considerou como variÃveis independentes a temperatura de secagem na entrada do equipamento e a concentraÃÃo de maltodextrina empregada, tendo como resposta a higroscopicidade, grau de caking, coordenada de cor b*, tempo de reidrataÃÃo e rendimento da produÃÃo do pÃ. Os pÃs obtidos foram considerados nÃo higroscÃpicos e, de acordo com estes resultados, foram selecionados como parÃmetros do processo o emprego de temperaturas de 73 ÂC e adiÃÃo de 11% de maltodextrina na secagem de sucos de tangerina com ou sem prÃ-biÃtico. NÃo houve diferenÃa significativa nos resultados de umidade, o grau de caking e solubilidade para os sucos de tangerina em pà com e sem prÃ-biÃtico, sendo que para a higroscopicidade os resultados foram considerados significativos a 5% de probabilidade, apresentando ainda maior luminosidade, coloraÃÃo mais clara e menor intensidade da cor amarela no suco prÃ-biÃtico em pÃ. / Functional foods have been taking more space as a good alternative in preventing diseases, but they are found as lactic products, and person with lactose intolerance cannot consuming them. The aim of this work was elaborate tangerine juice containing prebiotic oligosaccharides and their dehydration using spouted bed drying. Oligosaccharide synthesis was performed following a experimental design using the dextran-sucrase enzyme obtained by LeuconostocmesenteroidesB512F and the assay with oligosaccharide concentration of 61,28 g/L was selected. Fractioned Fatorial and Central Composite design was used to optimize the spouted bed drying. The first design was considered temperature, maltodextrin concentration, inert and feeding output as independent variables; process yield, powder water activity, rehydration time and moisture was dependent variables. The second design used inlet drying temperature and maltodextrin concentration as independent varibles, obtaining as responses higroscopicity, caking degree, b* color coordinate, rehydration time and powder production yield. Powders obtaining was no hygroscopicand, with this results, was selected as process parameters temperatures of 73 ÂC and maltodextrin concentration of 11 per cent on tangerine juice drying with or without prebiotic in. No significant difference was found for moisture, caking degree and solubility of tangerine juice powder with or without prebiotics. Hygroscopicity results was significant as 5% probability, showing high luminosity, lighter color and yellow less color at prebiotic powder juice.

O yacon (Smallanthus sonchifolius) é uma planta de origem andina, cujas raízes tuberosas armazenam açúcares como frutose, glicose, sacarose e, principalmente, frutooligossacarídeos (FOS). Os FOS são designados como prebióticos, que por sua não digestibilidade pelas enzimas do trato digestivo humano, estimulam seletivamente a multiplicação e a atividade de bactérias intestinais promotoras de saúde. Este trabalho visou estudar a separação de FOS do extrato de yacon, mediante o emprego do processo de separação por membranas (PSM) por ultrafiltração (UF) e avaliar as características físico-químicas do pó obtido por spray drying, a partir do permeado da UF. As raízes foram descascadas e cortadas em rodelas e submetidas ao branqueamento mediante vapor a 100ºC. A partir das fatias branqueadas foi extraído o suco empregando um processador de alimentos; da polpa obtida após a separação do suco, foram extraídos os açúcares restantes mediante a adição de água a 80°C em uma proporção de 2:1 (massa água/massa polpa). O suco de yacon e a solução líquida obtida da polpa foram separadamente filtrados e a mistura dos filtrados constituiu o extrato de yacon. A separação dos FOS foi realizada pelo processo de UF, utilizando duas membranas poliméricas de 10 kDa (UF-10) e 30 kDa (UF-30) com pressões transmembrana de 1,2 bar e 0,75 bar, respectivamente. Encontrou-se que o fluxo de permeado aumentou com o aumento da pressão de 0,5 bar a 2 bar e com a temperatura de 15ºC a 35ºC. Para a UF- 10, a resistência da membrana (Rm) aumentou de 3,25×1013 m-1 para 3,41×1013 m-1 com o aumento da pressão de 0,5 bar para 2 bar; o mesmo ocorreu com a UF-30, aumentando de 1,69×1013 m-1 para 1,89×1013 m-1. As resistências total (Rt), do fouling (Rf) e da polarização por concentração (Rc) apresentaram um leve incremento com o aumento da pressão. Com o aumento da temperatura os valores de Rf e Rc diminuíram devido à redução da viscosidade da solução, enquanto que Rt e Rm não variaram. A porcentagem de formação do fouling diminuiu com o aumento do poro da membrana, de 61,24% na UF-10 para 57,33% na UF-30. O entupimento dos poros da membrana foi revertido empregando procedimentos de limpeza, obtendo-se altas recuperações de fluxo de permeado (76,46% para UF-10 e 83,56% para UF-30). A retenção dos FOS foi de 24,48%, da glicose de 12,95% e da frutose de 22,18% na membrana UF-10, sendo que o aumento do tamanho de poro proporcionou menor retenção dos açúcares, 6,49%, 9,11% e 11,31% para os FOS, glicose e frutose respectivamente para a UF-30.O balanço de massa mostrou que os FOS obtidos no permeado da UF alcançaram pureza de 24,08% para a UF-10 e 18,43% para a UF-30. Ao permeado da UF foi adicionado goma arábica como agente encapsulante nas concentrações de 10% e 15% sob constante agitação até completa homogeneização, seguido de imediata secagem no spray dryer empregando temperaturas de entrada de ar de 140°C e 160°C. O p roduto final apresentou valores de umidade menores que 4 gH2O/100 g m.s. e de atividade de água menores que 0,15. O aumento da concentração de goma e da temperatura de secagem resultou em aumento na solubilidade dos pós, obtendo-se valores superiores a 90%, enquanto que a higroscopicidade diminuiu. A microscopia eletrônica de varredura mostrou que as partículas obtidas por atomização apresentaram tamanhos em torno de 5 μm e morfologias distintas, além de uma forte tendência à aglomeração das partículas menores em torno das maiores, principalmente na temperatura de 140ºC. Com relação à cor, o parâmetro L* diminuiu significativamente com o aumento da temperatura de 140ºC para 160ºC, resultando em amostras mais escuras; os parâmetros a* e b* indicaram que as amostras observadas foram esverdeadas e amareladas, com índice de escurecimento significativamente maior a 160ºC na UF-30. Durante a secagem, o aumento da temperatura diminuiu as concentrações de inulina, enquanto que os teores de glicose e frutose aumentaram devido à reação de termólise que levou à degradação das cadeias de inulina. Os ensaios de atividade prebiótica mostraram que todas as amostras de permeado e retido sem encapsulação foram metabolizados de forma semelhante à glicose pelas três diferentes bactérias (Lactobacillus acidophilus LA-5®, Bifidobacterium lactis BB-12® e Escherichia coli ATCC 25922). Com relação às amostras atomizadas, os tratamentos provenientes da UF-30 e que foram metabolizadas pela cultura probiótica LA-5 apresentaram indicativo potencial de atividade prebiótica, por terem sido metabolizadas de forma similar à glicose. / The yacon (Smallanthus sonchifolius) is a plant originated from Andean regions, whose tuberous roots contain sugars such as fructose, glucose, sucrose, and especially fructooligosaccharides (FOS). FOS is referred to as prebiotics due to it is not digestible by enzymes in the human digestive tract, therefore it selectively stimulates the multiplication and activity of health-promoting bacteria. This study aimed to evaluate the separation of FOS from the extract of yacon by ultrafiltration (UF) membrane separation process (PSM), and study the physic-chemical characteristics of the powder obtained by spray drying from the permeate obtained by UF. The juice was extracted from the bleached slices using a food processor; after, the remaining sugars were extracted from the pulp by adding water at 80ºC in a ratio of 2:1 (water / pulp). The yacon juice and the liquid solution obtained from the pulp were filtered and the filtrate mixture was the yacon extract. The separation of FOS was carried out by two polymeric membranes of 10 kDa (UF-10) and 30 kDa (UF- 30), at pressures of 1.2 bar and 0.75 bar, respectively. The permeate flux increased with increasing pressure from 0.5 bar to 2 bar and temperature from 15ºC to 35ºC. For the UF- 10, the intrinsic membrane resistance (Rm) increased from 3.25×1013 m-1 to 3.41×1013 m-1 with increasing pressure from 0.5 bar to 2 bar. The same occurred with UF-30, in which Rm increased from 1.69×1013 m-1 to 1.89×1013 m-1. The total resistance (Rt), fouling resistance (Rf) and cake layer resistance (Rc) slight increased with increasing pressure. As the temperature increased, the values of Rf and Rc decreased due to the reduced viscosity of the solution, while Rt and Rm values did not change. The percentage of membrane fouling decreased from 61.24% in UF-10 to 57.33% in UF-30 with increasing the membrane pore size. The membrane pore clogging was reversed by cleaning procedures, resulting in high recoveries of the permeate flow (76.46% in UF-10 and 83.56% in UF-30). For UF-10, the FOS retention was 24.48%, while glucose and fructose retention were 12.95% and 22.18% respectively, and the increase in pore size resulted in less retention of sugars, once for the UF-30 the retention percentage was 6.49%, 9.11% and 11.31% for FOS, glucose and fructose, respectively. The mass balance showed that FOS from the UF permeate reached 24.08% purity in UF-10 and 18.43% in UF-30. Gum arabic at concentrations of 10% and 15% was added to the UF permeate as an encapsulating agent with constant stirring until complete homogenization, followed by immediate drying in a spray dryer at inlet temperatures of 140ºC and 160ºC. The final product presented moisture content less than 4 gH2O/100 g d.m. and water activity less than 0.15. Increasing both the arabic gum concentration and drying temperature have increased the powder solubility, with values higher than 90%, and decreased hygroscopicity. Scanning electron microscopy showed that the atomized particles had about 5 μm diameter and exhibited different morphologies, with a strong tendency to particle agglomeration, once smaller particles appeared to overlap large particles, mainly at 140ºC. Regarding the color parameters, the parameter L* significantly decreased with increasing temperature from 140ºC to 160ºC, resulting in darker samples. The parameters a* and b* indicated that the samples were greenish and yellowish with significantly increase in the browning index at 160ºC for UF-30. During the drying process, increasing the temperature decreased inulin concentrations, whereas the levels of glucose and fructose increased due to the thermolysis reaction that lead to degradation of inulin chains. The prebiotic activity assay showed that all permeate and retentate samples without encapsulation were metabolized similarly to glucose by the three different bacteria (Lactobacillus acidophilus LA-5®, Bifidobacterium lactis BB-12® and Escherichia coli ATCC 25922). With respect to the atomized samples, the treatments from the UF-30 that were metabolized by the probiotic culture LA-5 seemed to present potential prebiotic activity, since they were metabolized in a manner similar to glucose metabolism.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T13:24:15Z No. of bitstreams: 2 Tese - Eliete Souza Santana - 2011.pdf: 2587838 bytes, checksum: d103db38e37de5827898dc565d152e78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T16:23:32Z (GMT) No. of bitstreams: 2 Tese - Eliete Souza Santana - 2011.pdf: 2587838 bytes, checksum: d103db38e37de5827898dc565d152e78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-05T16:23:32Z (GMT). No. of bitstreams: 2 Tese - Eliete Souza Santana - 2011.pdf: 2587838 bytes, checksum: d103db38e37de5827898dc565d152e78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-09-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Three experiments were performed aiming to elucidate aspects concerning the pathogenesis, clinical, pathological and immunological changes in turkeys inoculated with Salmonella Enteritidis, as well as the control and performace variables, with the use of lactulose. Experiment 1 consisted of three treatments and a control group. A second group inoculated with 6.0x102 CFU/mL and a third one inoculated with 7.0x105 CFU/mL of Salmonella Enteritidis. Within 1, 3, 6, 12, 18 and 24, and three, four, 38 and 49 days post-inoculation, two birds per treatment were sacrificed and vitelline sacs, spleen, bursa of Fabricius and ceca were coleted for Salmonella research, lymphocytes levels, and immunohistochemistry. The pathogen was isolated in organs studied in both tests and the lymphocytes levels decreased. Was observed that the dose influences the penetration, dissemination, and persistence of the pathogen elimination in turkeys. In Experiment 2, 160 turkeys were distributed into four treatments within 6.0x102CFU/mL, 7.0x105 CFU/mL, 8.0x109 CFU/mL of Salmonella Enteritidis and a control group. With 1, 3, 6, 12, 18 and 24 and three, four, 38 and 49 days were sampled blood, liver, spleen and bursa of Fabricius of two birds per treatment for electrophoretic, bacteriological and histopathological analysis, and also lymphocyte levels. There were differences in total serum protein data, as well as in bacterial isolation and tissue changes from 6 hours to 4 days before. The decrease of lymphocytes levels were registered from 3 hours post-inoculation. High mortality levels were observed in all groups in the first week, of which the main clinical and histopathological changes, as well the mortality levels were more evident in the group that received the highest dose. Was observed that serum proteins values, liver histopathological lesions, and decrease of lymphocytes levels occurs primarily in the first days post-infection. Experiment 3 consisted of 280 turkeys distributed in four treatments: placebo, control of lactulose; inoculated with 7.0x105 UFC/mL of Salmonella Enteritidis and inoculated with 7.0x105 UFC/mL of Salmonella Enteritidis and treated with lactulose. At seven, 21, 42 and 60 days were performed analisis of accomplishment. One bird of each quota was sacrificed and collected duodenum and jejunum from each for histomorphometric analysis, and ceca and inglúvios for enumerations of Enterobacteriaceae, Lactobacillus, Salmonella, pH measurements and biometric examination of intestines. Still, were collected liver, spleen, bursa of Fabricius and the gastrointestinal tract for bacteriological, histopathological, lymphocyte levels, and biometric examination. Were observed a lower weight gain in the group that received only the pathogen and increased only in patients that receiving lactulose. Were observed a higher correlation villous: crypt in the duodenum and jejunum of lactulose and placebo groups at seven and 21 days. Higher levels of UFC of Lactobacillus and Enterobacteriaceae were observed in the groups that receivied lactulose. Salmonella Enteritidis infections determine histopatological changes, decrease of lymphocyte levels and mortality. Lactulose increases beneficial bacteria, reduces the colonization of Salmonella, Promotes intestinal development and improved the animal performance, minimizes lymphocyte and tissue changes, reducing mortality and carrier state. / Foram desenvolvidos três experimentos com os objetivos de elucidar aspectos que envolvem a patogênese, clínica, alterações anatomopatológicas e imunológicas, bem como o controle com uso da lactulose e nas variáveis de desempenho de perus inoculados experimentalmente com Salmonella Enteritidis. Experimento 1 foi constituido de três tratamentos, sendo um grupo controle, um grupo inoculado com 6,0x102 UFC/mL e o terceiro inoculado com 7,0x105 UFC/mL de Salmonella Enteritidis. Com 1, 3, 6, 12, 18 e 24h e com três, quatro, 38 e 49 dias pós-inoculação, duas aves por tratamento foram sacrificadas e coletados sacos vitelínicos, baços, bursas de Fabricius e cecos, para pesquisa da Salmonella, contagem de linfócitos e imunoistoquímica. O patógeno foi identificado nos órgãos estudados em ambos os testes utilizados e o número de linfócitos foi reduzido. Em perus observou-se que a dose influencia a penetração, disseminação, eliminação e persistência do patógeno nos perus. No experimento 2 foram utilizados 160 perus, distribuidos em quatro tratamentos que receberam 6,0x102UFC/mL, 7,0x105 UFC/mL, 8,0x109 UFC/mL de Salmonella Enteritidis e um grupo controle. Com 1, 3, 6, 12, 18 e 24h e aos três, quatro, 38 e 49 dias foram coletados sangue, fígado, baço e bursa de Fabricius de duas aves por tratamento para análises eletroforéticas, bacteriológicas e histopatológicas e contagem de linfócitos, respectivamente. Houve diferença nos dados de proteínas séricas totais, assim como no isolamento bacteriano e nas alterações teciduais a partir de 6h até quatro dias. As depleções de linfócitos foram registradas a partir de 3h pós-inoculação. A mortalidade observada foi alta em todos os grupos na primeira semana, sendo que as principais alterações clínicas, histopatológicas e mortalidade foram mais evidentes no grupo que recebeu a maior dose. Verificou-se que os valores de proteínas séricas, lesões histopatológicas no fígado, bem como depleção de linfócitos ocorre principalmente nos primeiros dias pós-infecção. O Experimento 3 constituiu-se de 280 perus distribuídos em quatro tratamentos: placebo; controle da lactulose; inoculados com 7,0x105 UFC/mL e inoculados com 7,0x105 UFC/mL de Salmonella Enteritidis e tratados com a lactulose. Aos sete, 21, 42 e 60 dias foram realizadas análises de desempenho e uma ave de cada parcela foi sacrificada para coleta de duodenos e jejunos para análises histomorfométricas, inglúvios e cecos para enumerações de Enterobacteriaceae, Lactobacillus e Salmonella, aferições de pH e biometria de intestinos delgados e grossos. Ainda, foram coletados o fígado, baço, bursa de Fabricius e trato gastrintestinal, para análises bacteriológicas, histopatológicas, contagem de linfócitos, e exames biométricos. Observou-se, menor ganho de peso no grupo que recebeu somente o patógeno e maior no que recebeu somente a lactulose. Verificaram-se maiores relações vilos: criptas nos duodenos e jejunos dos grupos placebo e da lactulose aos sete e aos 21 dias. Maiores quantidades de unidades formadoras de colônias de Enterobacteriaceae e Lactobacillus foram observadas nos grupos que receberam a lactulose. Salmonella Enteritidis determina alterações histopatológicas e depleções linfocitárias e mortalidade. A lactulose aumenta bactérias benéficas, reduz a colonização de Salmonella, promove maior desenvolvimento intestinal e melhor desempenho, minimiza alterações teciduais e linfocitárias, reduzindo a mortalidade e o estado de portador.

Orientador: Mário Roberto Maróstica Júnior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T21:17:07Z (GMT). No. of bitstreams: 1 Vieira_VivianCristineCorreia_M.pdf: 754182 bytes, checksum: 49215dd5d03276c30e0579dcfc1f4984 (MD5) Previous issue date: 2012 / Resumo: Prebióticos são componentes alimentares não-digeríveis que conferem benefícios à saúde do hospedeiro por meio da modulação de sua microbiota gastrintestinal, tais como a oligofrutose e os galacto-oligossacarídeos (GOS). Diversos estudos têm sugerido que estes dois prebióticos podem estar associados à melhora da saúde óssea. Nas mulheres, a perda óssea associada ao envelhecimento tem início na terceira década de vida, e é bastante acentuada pela deficiência de estrógenos na menopausa, tendo-se um maior risco de desenvolvimento de osteoporose, doença esquelética sistêmica caracterizada por baixa massa e deterioração da microarquitetura do osso, com aumento do risco de fraturas. Assim, o objetivo deste estudo foi avaliar o efeito do consumo de oligofrutose, GOS e de sua combinação no metabolismo ósseo de ratas Wistar de meia-idade, nas quais ter-se-ia perda óssea associada ao envelhecimento e o estrógeno seria deficiente. Foi desenvolvido ensaio biológico com 32 ratas, divididas em 4 grupos: G1= dieta AIN-93M padrão (controle), G2=dieta AIN-93M com 5% de oligofrutose, G3=dieta AIN-93M com 5% de GOS, e G4=dieta AIN-93M com 5% de uma mistura deste prebióticos (1:1). A suplementação foi realizada por 16 semanas. Foram determinadas as concentrações séricas de paratormônio (PTH), ligante do receptor ativador do fator nuclear Kappa ß (RANK-L), osteoprotegerina (OPG) e interleucina 6 (IL-6) por meio de reações do tipo antígeno-anticorpo; a área óssea, conteúdo mineral ósseo e densidade mineral óssea da coluna lombar por meio de absorciometria por dupla emissão de raio-X (DXA), além de propriedades biomecânicas do fêmur dos animais em ensaio de flexão em três pontos. Na análise estatística dos resultados, utilizou-se o teste de Tukey para os dados paramétricos, e teste de Kruskal-Wallis para os dados não paramétricos, considerando p<0,05 como probabilidade mínima aceitável para diferença entre as médias. Não foram constatadas diferenças significantes entre os 4 grupos para todas as variáveis relacionadas ao metabolismo ósseo analisadas. Pode-se concluir que o consumo destes prebióticos nas concentrações do presente estudo por 16 semanas não contribuiu para melhorar a saúde óssea nesse grupo populacional / Abstract: Prebiotics are non-digestible food components that provide health benefits to the host through the modulation of the gastrointestinal microbiota, such as oligofructose and galactooligosaccharides (GOS). Several studies have demonstrated that consumption of these prebiotics might be associated with improved bone health. In women, age-related bone loss begins at the third decade of life, and it is markedly accentuated with estrogen deficiency at menopause, predisposing women at this stage to a higher risk of developing osteoporosis. This last is defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone susceptibility to fracture. Thus, the aim of this study was to evaluate the effect of oligofructose, GOS and their combination on bone metabolism in aging female rats, in which age-related bone loss occurs and estrogen is deficient. Thirty-two female Wistar rats were divided in 4 groups: G1= AIN-93M standard diet (control), G2=AIN-93-M diet with 5% of oligofructose, G3=AIN-93-M diet with 5% of GOS, G4=AIN-93-M diet with 5% of a mixture of oligofructose and GOS (1:1). The dietary intervention was carried out for 16 weeks. Serum concentrations of parathyroid hormone (PTH), receptor activator of NF-kB ligand (RANK-L), osteoprotegerin (OPG) and interleukin-6 (IL-6) were determined through antigen-antibody reactions. Lumbar vertebrae bone area, bone mineral content and bone mineral density were measured using dual X-ray absorptiometry, and femur specimens were submitted to a three-point bending test in order to obtain it¿s biomechanical properties. Statistics was performed using Tukey test for parametric data and Kruskal-Wallis test for non-parametric data. Results were considered statistically different at p < 0.05. There were no significant differences between the groups for all variables related to bone metabolism. In conclusion, consumption of these prebiotic ingredients for 16 weeks in the concentrations of the present study did not improve bone health in aging female rats / Mestrado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição

The interest for health, nutritive and well enjoyed food has increased worldwide and results in several studies in the area of dairy products. This paper aimed the development of yogurts with different concentrations of traditional and probiotic dairy cultures (0.5%, 1.0% and 1.5%). The process of fermentation was followed through the values of pH and acidity expressed in lactic acid. Physical and chemical analysis were carried out (pH value, acidity expressed in lactic acid, lactose proportion, umidity proportion, ash proportion, total dry and not greased extract proportion, protein proportion, fat proportion), color (CIELAB Sistem) and aparent viscosity after the fermentation and during the storage of the product. It was determined the viability of the traditional lactic bacteria (Streptococcus salivarius ssp. thermophilus, Lactobacillus delbrueckii ssp. bulgaricus) and the probiotic ones (Lactobacillus acidophilus and Bifidobacterium sp.) during the twenty-eight (28) days of storage. Sensorial tests of acceptance and preference were taken with adults and children. The collected data in this study were subjected to statistical analysis (average values with the respective standard deviations, analysis, variation analysis (ANOVA) by the Entirely Casual Delineation (ECD) and by Block Casual Delineation (BCD) and by Tukey's test). The results showed that different concentrations of lactic cultures influenced the fermentation time. There were not significant differences among the samples in relation with the physical and chemical characteristics. It was observed that there was a decrease of the pH value and the lactose proportion and an increase in the acidity expressed in lactic acid proportional to the increase in the concentration of lactic cultures. During the storage time it was noticed a significant decrease in the number of feasible cells of S. termophilus and L. bulgaricus, L. acidophilus and Bifidobacterium sp.. The sensorial analysis that, enerally, the yogurt with 1.0% of lactic cultures presentes the best grades concerning to evaluated attributes. The obtained results show the great potential for the production of yogurts using the probiotic lactic cultures. / O interesse por produtos alimentícios saudáveis, nutritivos e de grande aproveitamento tem aumentado mundialmente, o que resulta em diversos estudos na área de produtos lácteos. Este trabalho teve como objetivo o desenvolvimento de iogurtes com diferentes concentrações de culturas lácticas tradicionais e probióticas (0,5%, 1,0% e 1,5%). O processo de fermentação foi acompanhado através dos valores de pH e acidez expressa em ácido láctico. Foram realizadas análises físicoquímicas (valor de pH, acidez expressa em ácido láctico, teor de lactose, teor de umidade, teor de cinzas, teor de extrato seco total e desengordurado, teor de proteína, teor de gordura), cor (Sistema CIELAB) e viscosidade aparente após a fermentação e durante o armazenamento do produto. Determinou-se a viabilidade das bactérias lácticas tradicionais (Streptococcus salivarius ssp. thermophilus, Lactobacillus delbrueckii ssp. bulgaricus) e probióticas (Lactobacillus acidophilus e Bifidobacterium sp.) durante os 28 dias de armazenamento. Testes sensoriais de aceitação e preferência foram realizados com adultos e crianças. Os dados obtidos neste estudo foram submetidos a análises estatísticas (valores médios com os respectivos desvios padrão, análise de variância (ANOVA) por Delineamento Inteiramente Casualizado (DIC) e por Delineamento em Blocos Casualizados (DBC) e teste de Tukey). Os resultados mostraram que diferentes concentrações de culturas lácticas influenciaram o tempo de fermentação. Não houve diferenças significativas entre as amostras em relação as características físico-químicas. Observou-se que houve um decréscimo do valor de pH e do teor de lactose e um aumento na acidez expressa em ácido láctico proporcional ao aumento da concentração de culturas lácticas. Durante o tempo de estocagem notou-se um decréscimo significativo no número de células viáveis de S. thermophilus e L. bulgaricus e de L. acidophilus e Bifidobacterium sp.. A análise sensorial mostrou que de uma maneira geral o iogurte com 1,0% de culturas lácticas apresentou as melhores notas em relação aos atributos avaliados. Os resultados obtidos demonstram o grande potencial para a produção de iogurtes utilizando culturas lácticas probióticas.

Dans le contexte prébiotique du " monde ARN ", les ribonucléotides sont considérés comme étant les premières espèces à avoir émergé sur Terre. En milieu aqueux, leur formation est défavorable thermodynamiquement. Les voies de synthèse de nucléotides décrites en phase homogène impliquent l'utilisation des molécules activées. En 1951, Bernal a introduit une autre voie de synthèse impliquant des surfaces minérales. Cependant, dans cette voie, les effets thermodynamique et/ou catalytique des surfaces minérales restent inexplorés. Dans le cadre de l'hypothèse de Bernal, notre travail présente pour la première fois une étude in-situ de la réactivité thermique des " briques élémentaires " des nucléotides adsorbés sur des surfaces minérales avec comme objectif de réaliser la synthèse des nucléotides sans activation chimique. Ce travail a montré dans un premier temps que les surfaces minérales sont capables de déclencher la formation de polyphosphates inorganiques à partir de monophosphates à des températures modérées. D'autre part, l'adsorption du ribose sur la surface de la silice a permis d'améliorer sa stabilisation thermique : alors qu'il est instable dès 90°C en milieux aqueux, il devient stable jusqu'à 200°C après adsorption sur la silice. Dans un deuxième temps, nous avons mis en évidence la formation de PRPP, un intermédiaire réactionnel très important, par co-adsorption du ribose avec du phosphate inorganique sur la surface de la silice. Enfin, on a pu montrer la glycosylation de l'adénine et la formation après co-adsorption de ses composants sur les deux surfaces minérales utilisées. Une étude préliminaire suggère même la possibilité de dimérisation des nucléotides. / In the « RNA world» prebiotic scenario, ribonucleotide polymers are considered as the first biochemical species to have emerged. However, in aqueous solution, their formation through conventional mechanisms of condensation is thermodynamically forbidden. Several synthesis pathways of nucleotides have been described in aqueous solution; most often, they involve chemically activated molecules. Another pathway to nucleotides implies mineral surfaces, which have been considered in prebiotic processes at least since the work of Bernal in 1951. However, these studies have hardly tried to understand surface-molecule interactions and consequently, thermodynamic and/or catalytic effects of mineral surfaces are not well rationalized. In the context of Bernal's hypothesis, we present for the first time an in-situ study of the thermal reactivity of nucleotides “building blocks” adsorbed on mineral surfaces (amorphous silica, saponite) emphasizing the synthesis of nucleotides without chemical activation. In our work, we first show that mineral surfaces are able to trigger the formation of inorganic polyphosphates from monophosphates at moderate temperatures. On the other hand, adsorption of ribose on silica surface improves its thermal stabilization. While ribose decomposes at 90°C in aqueous solutions, it is stable up to 200°C on silica (in the presence of ZnCl2). Secondly, we have demonstrated the formation of PRPP, as important reaction intermediate, by co-adsorption of ribose and inorganic phosphate on the silica surface. Finally, we showed the glycosylation of adenine to adenosine and the formation of AMP (i.e. simultaneous glycosylation and phosphorylation) after co-adsorption of their components on both mineral surfaces employed. A preliminary study even suggests that nucleotide dimerisation can occur in the same conditions.

The microbial populations in the gastrointestinal tracts of poultry play an important role in normal digestive processes and in maintaining animal health. The purpose of this study was to evaluate the effects of probiotics, prebiotics and synbiotics on the growth parameters, gut ecosystem, histology and immune function. In this study, four experiments one in vitro and three in vivo were conducted using specific pathogen free (SPF) and Hubbard broiler chickens. The first experiment was designed to determine the influence of inulin as an effective prebiotic on lactic acid bacteria (LAB) strains, and to screen LAB for selection as a source of chicken probiotic. Eight strains of LAB were isolated from chicken caeca and three strains from the Plymouth University culture collection were screened for potential probiotic properties for growth in inulin from Jerusalem artichoke (Helianthus tuberosus) and commercial inulin (Frutafit® HD, Netherlands). Lactobacillus animalis JCM 8692 strain isolated from chicken caeca showed the highest auto-aggregation and co-aggregation ability, resistance to acidity and bile salts, strong suppression of pathogens and ability to adhere to epithelial cells compared with other isolated strains. The second experiment was conducted to investigate the influence of commercial inulin and Jerusalem artichoke tubers as prebiotic supplementation on the diversity of the caecal microflora, jejunum histology and immune organ of SPF chickens. This investigation has found that inulin which was extracted from JA had a similar result when compared with commercial inulin and could be a suitable candidate for an inulin source in broiler diets. The third experiment was conducted to investigate the influence of Bactocell® (PRO1) and Lb. animalis (PRO2) as probiotic supplements on broiler chickens. EPEF was significantly increased in probiotic1 and probiotic2 compared with control (311.03, 309.87 and 260.06) respectively. Both types of probiotics supported the growth of chicks healthy and could be a suitable candidate as a source of probiotic in broiler diet. The fourth experiment was conducted to investigate the influence of dietary supplementation of a probiotic (Lb. animalis), a prebiotic JA tuber and a combination of both (Synbiotic) in broiler chickens. Growth performance was improved in all additive supplementation compared with the control group. EPEF was increased in probiotic, prebiotic and synbiotic compared with control (290.8±11.8, 300.9±3.86, 322.1±7.09 and 262.3±5.94) respectively. Beneficial bacteria in the guts of chicks fed probiotic, prebiotic and synbiotic was increased compared with chicks fed control diet. The diversity of microbial population in the gastrointestinal tract of chickens improved due to additives. The intestinal villus lengths and microvilli density was improved in all additives supplementation in comparison with control. Overall, it was concluded that probiotic, prebiotic and synbiotics can positively affect production performance and can improve the gut health.

The Sutherland group recently demonstrated that from a mixture of oligoribonucleotide-2'- or 3'-phosphates the latter is chemoselectively acetylated. This is shown to mediate a template-directed ligation to give predominantly 3',5'-linked RNA that is acetylated at the ligation junction (acetyl-RNA). It was suggested that RNA emerged prebiotically via acetyl-RNA and also is proposed to have favourable genotypic properties due to greater propensity to form duplex structure. To study the properties of acetyl-RNA, their synthesis by solid-phase chemistry was required and described is the design of a 2'/3'-O-acetyl orthogonal protecting group strategy. Key to the orthogonal protecting group strategy is the use of (2-cyanoethoxy)carbonyl for the protection of the nucleobase exocyclic amines and a photolabile solid-phase linker group that allowed partial on-column deprotection. The synthesis of the 2'/3'-O-acetyl and 2'/3'-O-TBDMS phosphoramidites, in addition to preparation of a photolabile solid-phase support, are described. With the materials to hand the procedures for an automated synthesis of acetyl-RNA were optimised and several acetyl-RNA oligonucleotides were synthesised. The duplex stability of acetyl-RNA with up to four sites of 2'-O-acetylation were assessed by UV melting curve analysis. Remarkably, the acetyl groups caused a consistent decrease in Tm of between 3.0-3.2 °C. Thermodynamic parameters indicated a decrease in duplex stability that was consistent with a decrease in hydration of the minor groove resulting in a reduction of the stabilising hydrogen bonding network. The stability of a tetraloop was also found to decrease on acetylation. The acetylated- tetraloop it is able to form duplex at lower concentrations than the natural tetraloop. Additionally, it is more stable at high concentrations, indicating that acetyl-RNA favours duplex over other secondary structure. These properties are considered to give acetyl-RNA competitive advantage for their non-enzymatic replication. Aminoacylation of RNA is an important process in modern biology but the intermediacy of aminoacyl-adenylates is considered to be prebiotically implausible. A potentially prebiotic aminoacylation of nucleoside-3'-phosphates, selective for the 2'-hydroxyl, is presented. However, it was thought the aminoacylation yields could be improved and so a search for an alternative activator was conducted. Oligoribonucleotide-3'-phosphates were exposed to the aminoacylation conditions and selective aminoacylation at only the 2'-hydroxyl of the 3'-end was observed. In particular, the aminoacylation of a trimer lends support to Sutherland’s theory of a linked origin of RNA and coded peptide synthesis.