Stomata are small pores that are located on the surface of epidermal leaves, and they can regulate the uptake of CO2 and prevent water lose by opening and closing the pores. Stomata of plants can be regulated by external condition such as CO2, biotic and abiotic stresses and internal factors. CAM (crassulacean acid metabolism) plants adapt to hot and dry environments by closing stomata during the day and opening stomata during the cool night. However, it is still unclear how CAM plants open their stomata during the night and close them during the day. In this study, a number of factors were evaluated for their potential roles in promoting stomatal opening in the model CAM plant Kalanchoe laxiflora. Citrate is an important organic acid and it accumulates during the night in CAM plants. It is shown in this study that citrate promoted stomatal opening in detached leaf epidermis of Kalanchoe laxiflora. Further, the cytokinin zeatin is also shown to stimulate stomatal opening in detached leave of Kalanchoe laxiflora. Melatonin is an important regulator of circadian rhythms in mammals and has been implicated in regulation of plant abiotic stress responses. Melatonin was detected in the leaves of Kalanchoe laxiflora. It promoted stomatal opening in detached epidermis of Kalanchoe laxiflora. Together, these results suggest that stomata of Kalanchoe laxiflora respond to citrate and malate which are the main organic acids accumulate during nighttime and also to some signaling molecules (zeatin, melatonin, and serotonin) by opening stomata during dark period.

Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria (PGPR). This study observes the soybean growth promoting potential of Pseudomonas spp. in a field setting. Additionally, this study observed differences in soybean growth promotion based on amending the plant with isolated strains or a mixed culture of the species' strains. Two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were either amended with isolated strains of the novel Pseudomonas spp. (referred to as PAMW1 and BUMW2 in this study), a mix of the two strains, or an uninoculated control. The study recorded measurements to observe growth, yield, and nitrogen fixation differences. The study uses two-way factorial ANOVAs and non-parametric, multivariate analyses to determine differences in growth promotion among samples. Soybean amended with PAMW1 has greater shoot mass, biomass, and height than other treatments. Through nonmetric multidimensional scaling (NMS), samples amended with a mixed culture or PAMW1 may be different regarding growth promotion relative to the non-amended samples. Univariate results support the hypothesis that the novel Pseudomonas spp. benefit soybean in a field setting. However, it is inconclusive whether a mixed culture amendment of multiple strains alters the overall growth promotion of soybean compared to samples amended with isolated strains. / Master of Science / Soil hosts a relatively abundant and diverse community of microorganisms. Moreover, the area of soil that interacts closely with plant roots and their associated exudates, called the rhizosphere, has a significantly greater microbial abundance than surrounding bulk soil. Interactions between microbes and the plant often promote plant growth because of secondary metabolites produced by these beneficial microbes. One particular bacterial species, belonging to the Pseudomonas genus, was discovered and extracted from the soybean nodule interior. Nitrogen-fixing bacteria predominantly reside in the soybean nodule, yet this microorganism cannot fix nitrogen. Although trace amounts of non-nitrogen-fixing bacteria reside in the soybean nodule, this novel species has a relatively high abundance. This study determines the benefits of this species in the soybean nodule. Following positive results in a greenhouse study, this field experiment observes variance in soybean growth and productivity based on their received bacterial amendment. For this study, two soybean cultivars were either amended with an isolated strain of this species, a mix of the two strains, or left uninoculated to serve as a control. Numerous recorded measurements serve as indices of soybean growth and productivity. The results suggest that this novel Pseudomonas species benefits the plant by significantly improving biomass. With further research, this species can potentially serve as an environmentally sensitive and sustainable alternative to fertilizers through its ability to promote soybean growth.

O presente trabalho teve como objetivo avaliar, por meio da microscopia eletrônica de varredura (MEV), a capacidade de remoção da smear layer dos terços médio e apical do canal radicular utilizando soluções quelantes e desmineralizantes e, quantificar, por meio da espectrometria de absorção atômica com chama, a concentração de íons cálcio presentes nessas soluções após suas utilizações. Vinte e cinco caninos superiores foram preparados pela técnica Free Tip Preparation com 4 instrumentos acima do inicial e irrigados com hipoclorito de sódio 1% a cada troca de instrumento. Os dentes foram distribuídos aleatoriamente em 4 grupos, conforme protocolo utilizado para a irrigação final: G1 - EDTA 15%, G2 - quitosana 0,2%, G3 - ácido cítrico 10%, G4 - ácido acético 1%. O grupo controle (G5) não recebeu irrigação. Foram utilizados 5 mL de cada solução por 3 minutos. Após percorrer toda extensão do canal radicular a solução extravasada pelo forame foi coletada e encaminhada para análise espectrométrica. Os espécimes foram seccionados longitudinalmente e preparados para análise em MEV. As fotomicrografias obtidas foram avaliadas qualitativamente por três examinadores, que atribuíram escores às imagens, conforme a quantidade de smear layer. Os dados obtidos pela MEV foram analisados estatisticamente por meio do Teste de Kruskal-Wallis e Dunn. Para avaliação da espectrometria utilizou-se Tukey-Kramer (one-Way ANOVA). Os resultados mostraram que o EDTA 15%, quitosana 0,2% e ácido cítrico 10% removeram a smear layer de forma semelhante entre si e estatisticamente diferente (p<0,05) do ácido ácético 1% e controle. Não houve diferença na capacidade de limpeza das soluções quando os terços médio e apical foram comparados. A maior concentração de íons cálcio foi observada no grupo do EDTA 15% e quitosana 0,2%, sem diferença entre ambos. O grupo do ácido acético 1% apresentou as menores concentrações e o ácido cítrico 10%, concentrações intermediárias e diferentes estatísticamente dos dois grupos (p<0,01). Concluiu-se que as soluções de EDTA 15%, quitosana 0,2% e ácido cítrico 10% foram eficientes na remoção da smear layer do terço médio e apical do canal radicular. As soluções de EDTA 15% e quitosana 0,2% promoveram o maior efeito desmineralizante, seguidas pelo ácido cítrico 10% e acido acético 1%. / This study aimed to evaluate, by scanning electron microscopy (SEM), the ability to remove the smear layer from the apical and middle thirds of the root canal using chelators and demineralizing solutions, and quantify, by atomic absorption spectrophotometry flame, the concentration of calcium ions present in these solutions after their use. Twenty-five canines were prepared by Free Tip Preparation Technique with four instruments above the initial and irrigated with 1% sodium hypochlorite in each change of instrument. The teeth were randomly divided into four groups, according to the protocol used for the final irrigation: G1 - EDTA 15%, G2 - 0.2% chitosan, G3 - citric acid 10%, G4 - 1% acetic acid. The control group (G5) did not receive irrigation. We used 5 mL of each solution for 3 minutes. After irrigating the entire length of the root canal through the apical foramen, the solution was collected and sent to spectrometric analysis. The specimens were sectioned longitudinally and prepared for SEM analysis. The photomicrographs were qualitatively evaluated by three observers, who attributed scores to the images, equivalent to the amount of smear layer removal. The data obtained by SEM was statistically analyzed using the Kruskal-Wallis and Dunn tests. To evaluate the spectrometer, the Tukey-Kramer (one-way ANOVA) was used. The results showed that 15% EDTA, 0.2% chitosan and 10% citric acid had a similar smear layer removal with statistically different (p <0.05) when compared to 1% acetic acid and the control group. There was no difference between the solutions cleaning ability when the middle and apical thirds were compared. The highest concentration of calcium ions was observed in 15% EDTA group and 0.2% chitosan, with no statistical difference between them. The 1% acetic acid group had the lowest concentration and the 10% citric acid intermediate concentrations with statistical difference between each other (p <0.01). It can be concluded that the solutions of 15% EDTA, 0.2% chitosan and 10% citric acid were effective in removing the smear layer of the middle and apical thirds of the root canal. 15% EDTA solutions and 0.2% chitosan promoted the greatest effect on the demineralization, followed by 10% citric acid and 1% acetic acid.

No presente trabalho foram estudadas as propriedades mecâncias (resistência à tração e porcentagem de alongamento na ruptura e resistência à perfuração), propriedades ópticas, permeabilidade ao gás oxigênio e ao vapor d\'água, migração total em simulante aquoso (ácido acético 3%) e gorduroso (n- heptano), e a formação de produtos voláteis da radiólise, com vistas à avaliar o efeito da radiação ionizante (raios gama e feixe de elétrons) em filmes flexíveis mono e multicamadas comerciais, fabricados no Brasil para a indústria de produtos cárneos. Os filmes estudados foram: um monocamada de polietileno de baixa densidade (LDPE) e um multicamadas coextrusado composto de polietileno de baixa densidade (LDPE), copolímero de etileno e álcool vinílico (EVOH) e poliamida (PA), ou seja, a estrutura: LDPE/EVOH/PA. As irradiações foram realizadas em uma fonte de 60Co do tipo Gammacell e em um acelerador de elétrons do tipo eletrostático (l,5MeV), com doses de até 30 kGy, na temperatura ambiente e presença de ar. As alterações nas propriedades foram avaliadas de acordo com a dose de radiação aplicada, oito dias após a irradiação e novamente, dois a três meses após a irradiação. Os resultados mostraram que as reações de cisão predominaram sobre as reações de reticulação para ambos os filmes estudados, irradiados com raios gama ou com feixe de elétrons. As variações observadas em função da irradiação, nas propriedades avaliadas não limitam a aplicação final desses filmes, uma vez que não ultrapassaram o limite de segurança especificado pelo fabricante em nenhuma dose e período em que foram estudadas. Concluiu-se que os filmes estudados podem ser utilizados, sob o ponto de vista das propriedades avaliadas, como embalagens para produtos pasteurizáveis por radiação e radioesterilizáveis usando irradiadores gama ou aceleradores de elétrons, nas doses de radiação estudadas. / In this study the mechanical properties (tensile strength and percentage elongation at break and penetration resistance), optical properties, gas oxygen and water vapor permeability, the overall migration tests into aqueous food simulant (3% aqueous acetic acid) and fatty food simulant (n-heptane), as well as the formation of volatile radiation product tests were used to evaluate the effects of ionizing radiation (gamma irradiation or electron-beam irradiation) on commercial monolayer and multilayer flexible plastics packaging materials. These films are two typical materials produced in Brazil for industrial meat packaging, one of them is a monolayer low-density polyethylene (LDPE) and other is a multilayer co extruded low-density polyethylene (LDPE), ethylene vinyl alcohol (EVOH), polyamide (PA) based film (LDPE/EVOH/PA). Film samples were irradiated with doses up to 30 kGy, at room temperature and in the presence of air with gamma rays using a 60Co facility and electron beam from 1.5 MeV electrostatic accelerator. Alterations of these properties were detected according to the dose applied initially eight day after irradiation took place and new alterations of these values when the properties were evaluate two to three months after irradiation process. The results showed that scission reactions are higher than cross-linking process for both studied films, irradiated with gamma rays and electron beam. The evaluated properties of the irradiated films were not affected significantly with the dose range and period studied. The monolayer Unipac PE-60 and the multilayer Lovaflex CH 130 films can be used as food packaging materials for food pasteurization and in the sterilization process of by ionizing radiation using a gamma facilities and electron beam accelerators in commercial scale.

A esterificação do sec-butanol com ácido acético, submetida à catálise homogênea, apresenta poucos resultados experimentais de cinética reacional e equilíbrio químico disponíveis na literatura. A presente dissertação visa determinar os parâmetros cinéticos e de equilíbrio químico desta reação de esterificação, empregando modelo cinético de 2ª ordem baseado em atividades. Os experimentos cinéticos foram realizados em reator batelada com auxílio da metodologia Karl Fischer para análise do teor de água e determinação do perfil de frações molares ao longo da reação. A principal dificuldade na modelagem desta esterificação consistiu em representar satisfatoriamente as não-idealidades da mistura em fase líquida, em espacial nas reações cuja fração molar inicial de ácido acético foi superior a 50%. Netas condições admitiu-se a ocorrência de dissociação do ácido acético levando ao surgimento de interações iônicas. O modelo empregado para obtenção das atividades, com base em frações molares, foi o NRTL. Este modelo representou bem as interações moleculares em condição de baixa acidez, mas apresentou desvios em condições de acidez e teores de água mais elevados. O estudo também visou o desenvolvimento de modelos de calibração para um método analítico on-line visando determinar o perfil de frações molares ao longo da reação. O método empregado foi a espectroscopia de infravermelho próximo (NIR), em vista à capacidade deste método analítico em determinar quantitativamente frações molares de água, além dos demais compostos envolvidos. Outro fator determinante ao emprego do NIR é a seu crescente uso no meio industrial, e o presente trabalho visou também contribuir para o uso futuro desta técnica de monitoramento no processo industrial. Modelos de calibração multivariável com conjuntos de calibração interna por validação cruzada se mostraram adequados ao sistema estudado. Calibrações externas resultaram em modelos imprecisos, não sendo possível determinar claramente os fatores responsáveis pela imprecisão. / There is a lack of literature data on the reaction kinetics and equilibrium of the homogeneously catalyzed esterification of sec-butanol with acetic acid. This work aims at obtaining the kinetic parameters and chemical equilibrium parameters of this esterification reaction by using a second order kinetic model based on activities. The kinetic experiments were performed in a batch reactor and the Karl Fischer analytical method was used to determine the molar fraction of water along the reaction progress. The main challenge of modeling this reaction was to represent the highly non-ideal mixture in liquid phase, specially for reactions runs starting with acetic acid mole fraction higher than 50%. In these conditions, it was assumed the occurrence of acetic acid dissociation that leads to ionic interactions. The thermodynamic model used to calculate the activities was the NRTL. This model predicted well the molecular interactions on low acidity conditions but presented deviations when molar fractions of acid and water were higher. The present study also aims to develop calibration models for analytical on-line method to obtain molar fraction profiles along the reaction. Near infrared spectroscopy (NIR) was used due to the possibility of quantitatively analyze water mole fraction, besides the mole fractions of the other components. Another important reason to choose NIR was its crescent use in industry, and the present work intended to contribute towards the future use of this on line monitoring technique in industrial applications. Multivariate calibration models using internal set of calibration and cross-validation seems to be suitable for this system. External set of calibration leads to less accurate models, and the causes of this lack of accuracy were not clearly identified.

Neste trabalho avaliou-se a produção de compostos de interesse biotecnológico potenciais vetores energéticos a partir de papel em lisímetros &#40;20L&#41;, usando-se consórcio microbiano enriquecido do fluido de rúmen. Para tanto, foi realizado um delineamento composto central &#40;DCC&#41; para verificar a influência de três variáveis independentes na conversão de papel sulfite a hidrogênio e outros compostos orgânicos em lisímetro de bancada. As variáveis testadas foram massa de papel &#40;X1: 500g, 750g e 1000g&#41;, teor de umidade papel &#40;X2: 50&#37;, 65&#37; e 80&#37;&#41;, e temperatura &#40;X3:35&#176;C, 45&#176;C e 55&#176;C&#41;. As respostas avaliadas no DCC foram produção de hidrogênio &#40;Y1; mmol&#41;, ácido acético &#40;Y2; mg&#47;L&#41;, etanol &#40;Y3; mg&#47;L&#41; e metanol &#40;Y4; mg&#47;L&#41;. Para o monitoramento dos lisímetros em relação à hidrólise e fermentação do papel, foram analisados biogás &#40;H2, N2, CO2 e CH4&#41; e a concentração de compostos no percolado, como açúcares totais, demanda química de oxigênio &#40;DQO&#41;, ácidos orgânicos voláteis &#40;AOVs&#41; e álcoois. Além disso, monitorou-se o pH, alcalinidade e sólidos totais. Sequenciamento massivo do gene RNAr 16S via Plataforma Illumina foi usado para identificação dos micro-organismos do fluido de rúmen in natura, do consórcio enriquecido, e daqueles dos lisímetros R2, R5 e R9. Produção de hidrogênio só foi observada nos lisímetros R1 &#40;25 mmol&#41;, R2 &#40;35 mmol&#41; e R5 &#40;3 mmol&#41;, sendo os três com umidade inicial de 80&#37;. Em R1 e R2, observou-se elevadas concentrações de ácido acético, de 21.500 e 17.000 mg&#47;L, respectivamente, provavelmente devido à ocorrência de homoacetogênese. Sob temperatura termofílica, especialmente em R5, observou-se consumo de hidrogênio, e produção de etanol &#40;2.300 mg&#47;L&#41; e metanol &#40;5.600 mg&#47;L&#41;. Na condição de 80&#37; de umidade &#40;R1, R2, R5, R6&#41;, verificou-se maiores percentuais de remoção de papel e atividade fermentativa mais acentuada, ao passo que abaixo de 80&#37;, o desenvolvimento microbiano foi desfavorecido, independente da temperatura. Verificou-se consumo muito reduzido de papel e baixas concentrações de AOVs e álcoois para R3, R4, R7 e R8, todos com 50&#37; umidade. Em R9 e R10, operados a 45 &#176;C e 65&#37; de umidade, também verificou-se produção atenuada de AOVs e álcoois, com ausência de hidrogênio. Por meio do DCC, observou-se efeito estatisticamente significativo da umidade do papel na produção de hidrogênio, ácido acético e etanol. Em relação à temperatura, verificou-se efeito positivo estatisticamente significativo na produção de hidrogênio e ácido acético. Por fim, para a massa de papel não se verificou nenhum efeito sobre as respostas analisadas. Os gêneros de bactérias mais abundantes foram: Prevotella no fluido de rúmen in natura &#40;F.N.&#41; Dysgonomonas no fluido de rúmen enriquecido e em R2 &#40;35&#176;C&#41;, Thermicanus em R5 &#40;55&#176;C&#41; e Phaeospirillum em R9 &#40;45&#186;C&#41;. A umidade foi o parâmetro mais determinante para promover a hidrólise e fermentação do papel; a temperatura foi a principal variável de influência na estrutura das comunidades microbianas dos lisímetros, confirmada pelas diferentes rotas metabólicas observadas sob temperatura mesofílica e termofílica; e os rendimentos de produção dos compostos não foram influenciados pela massa de papel adicionada aos lisímetros. / This study evaluated the production of compounds of biotechnological interest and potential energy vectors from office paper in lysimeters &#40;20L&#41;, using a microbial consortium purified from rumen fluid. A central composite design &#40;CCD&#41; was performed to verify the influence of three independent variables on paper conversion to hydrogen and other organic compounds in bench lysimeter. The tested variables were: mass of paper &#40;x1: 500g, 750g and 1000g&#41;, moisture content &#40;x2: 50&#37;, 65&#37; and 80&#37;&#41;, and incubation temperature &#40;x3: 35&#176;C, 45&#176;C and 55&#176;C&#41;. The dependent variables of CCD were production of hydrogen &#40;Y1: mmol&#41;, acetic acid &#40;Y2: mg&#47;L&#41;, ethanol &#40;Y3:mg&#47;L&#41; and metanol &#40;Y4:mg&#47;L&#41;. For monitoring the lysimeters in relation to paper hydrolysis and fermentation, analyses of biogas &#40;H2, N2, CO2 and CH4&#41; and the organic compounds&#39; concentrations in the leachate, such as, total sugars, chemical oxygem demand, volatile organic acids &#40;VOA&#39;s&#41; and alcohols were conducted during operation. Alcalinity, pH and total solids content of the leachate were also monitored. Massive sequencing of rRNA 16S &#40;Illumina&#41; was carried out for identification of the microorganisms of the in natura rumen fluid, the purified consortium, and those collected from lysimeters R2, R5 and R9. Hydrogen production was detected only in lysimeters R1 &#40;25 mmol&#41;, R2 &#40;35 mmol&#41; and R5 &#40;3 mmol&#41;, all of them operated with 80&#37; of moisture content. In R1 and R2, high concentrations of acetic acid, of 21.500 and 17.000, respectively, were due to the likely occurrence of homoacetogenesis. Under thermophilic temperature, especially R5, the hydrogen production was detected in low quantity, and the highlight was the production of ethanol and methanol, with concentrations around 2.300 and 5.600 mg&#47;L, respectively. At 80&#37; moisture condition &#40;R1, R2, R5, R6&#41;, high percentages of paper removal and sharp fermentative activity were observed. However, at lower moisture conditions, the microbial growth was unfavored, independent of the temperature. Low paper consumption and reduced concentrations of OVA&#39;s and alcohols were detected in R3, R4, R7 and R8, all of them operated with 50&#37; of moisture content. In R9 and R10, operated at 45&#176;C and 65&#37; of moisture, there was also attenuated production of VOA\'s and alcohols, with absence of hydrogen. According to CCD statistical analysis, paper moisture content had positive effect statistically significative on hydrogen, acetic acid and etanol production. The temperature had positive effect on hydrogen and acetic acid production. And the mass of paper dit not have effect statistically significative for any dependent variables. The most abundant bacterial genus was: Prevotella in the in natura rumen fluid &#40;F.N.&#41; Dysgonomonas in the purified consortium and R2 &#40;35 oC&#41;, Thermicanus in R5 &#40;55&#176;C&#41; and Phaeospirillum in R9 &#40;45&#176; C&#41;. In conclusion, moisture content was the main parameter to promote paper hydrolysis and fermentation; temperature was the principal variable that influenced the structure of microbial community, confirmed by the different metabolic route observed under mesophilic and thermophilic conditions; and the production yields of the compounds were not influenced by the mass of paper added to the lysimeters.

No presente trabalho foram estudadas as propriedades mecâncias (resistência à tração e porcentagem de alongamento na ruptura e resistência à perfuração), propriedades ópticas, permeabilidade ao gás oxigênio e ao vapor d\'água, migração total em simulante aquoso (ácido acético 3%) e gorduroso (n- heptano), e a formação de produtos voláteis da radiólise, com vistas à avaliar o efeito da radiação ionizante (raios gama e feixe de elétrons) em filmes flexíveis mono e multicamadas comerciais, fabricados no Brasil para a indústria de produtos cárneos. Os filmes estudados foram: um monocamada de polietileno de baixa densidade (LDPE) e um multicamadas coextrusado composto de polietileno de baixa densidade (LDPE), copolímero de etileno e álcool vinílico (EVOH) e poliamida (PA), ou seja, a estrutura: LDPE/EVOH/PA. As irradiações foram realizadas em uma fonte de 60Co do tipo Gammacell e em um acelerador de elétrons do tipo eletrostático (l,5MeV), com doses de até 30 kGy, na temperatura ambiente e presença de ar. As alterações nas propriedades foram avaliadas de acordo com a dose de radiação aplicada, oito dias após a irradiação e novamente, dois a três meses após a irradiação. Os resultados mostraram que as reações de cisão predominaram sobre as reações de reticulação para ambos os filmes estudados, irradiados com raios gama ou com feixe de elétrons. As variações observadas em função da irradiação, nas propriedades avaliadas não limitam a aplicação final desses filmes, uma vez que não ultrapassaram o limite de segurança especificado pelo fabricante em nenhuma dose e período em que foram estudadas. Concluiu-se que os filmes estudados podem ser utilizados, sob o ponto de vista das propriedades avaliadas, como embalagens para produtos pasteurizáveis por radiação e radioesterilizáveis usando irradiadores gama ou aceleradores de elétrons, nas doses de radiação estudadas. / In this study the mechanical properties (tensile strength and percentage elongation at break and penetration resistance), optical properties, gas oxygen and water vapor permeability, the overall migration tests into aqueous food simulant (3% aqueous acetic acid) and fatty food simulant (n-heptane), as well as the formation of volatile radiation product tests were used to evaluate the effects of ionizing radiation (gamma irradiation or electron-beam irradiation) on commercial monolayer and multilayer flexible plastics packaging materials. These films are two typical materials produced in Brazil for industrial meat packaging, one of them is a monolayer low-density polyethylene (LDPE) and other is a multilayer co extruded low-density polyethylene (LDPE), ethylene vinyl alcohol (EVOH), polyamide (PA) based film (LDPE/EVOH/PA). Film samples were irradiated with doses up to 30 kGy, at room temperature and in the presence of air with gamma rays using a 60Co facility and electron beam from 1.5 MeV electrostatic accelerator. Alterations of these properties were detected according to the dose applied initially eight day after irradiation took place and new alterations of these values when the properties were evaluate two to three months after irradiation process. The results showed that scission reactions are higher than cross-linking process for both studied films, irradiated with gamma rays and electron beam. The evaluated properties of the irradiated films were not affected significantly with the dose range and period studied. The monolayer Unipac PE-60 and the multilayer Lovaflex CH 130 films can be used as food packaging materials for food pasteurization and in the sterilization process of by ionizing radiation using a gamma facilities and electron beam accelerators in commercial scale.

Neste trabalho avaliou-se a produção de compostos de interesse biotecnológico potenciais vetores energéticos a partir de papel em lisímetros &#40;20L&#41;, usando-se consórcio microbiano enriquecido do fluido de rúmen. Para tanto, foi realizado um delineamento composto central &#40;DCC&#41; para verificar a influência de três variáveis independentes na conversão de papel sulfite a hidrogênio e outros compostos orgânicos em lisímetro de bancada. As variáveis testadas foram massa de papel &#40;X1: 500g, 750g e 1000g&#41;, teor de umidade papel &#40;X2: 50&#37;, 65&#37; e 80&#37;&#41;, e temperatura &#40;X3:35&#176;C, 45&#176;C e 55&#176;C&#41;. As respostas avaliadas no DCC foram produção de hidrogênio &#40;Y1; mmol&#41;, ácido acético &#40;Y2; mg&#47;L&#41;, etanol &#40;Y3; mg&#47;L&#41; e metanol &#40;Y4; mg&#47;L&#41;. Para o monitoramento dos lisímetros em relação à hidrólise e fermentação do papel, foram analisados biogás &#40;H2, N2, CO2 e CH4&#41; e a concentração de compostos no percolado, como açúcares totais, demanda química de oxigênio &#40;DQO&#41;, ácidos orgânicos voláteis &#40;AOVs&#41; e álcoois. Além disso, monitorou-se o pH, alcalinidade e sólidos totais. Sequenciamento massivo do gene RNAr 16S via Plataforma Illumina foi usado para identificação dos micro-organismos do fluido de rúmen in natura, do consórcio enriquecido, e daqueles dos lisímetros R2, R5 e R9. Produção de hidrogênio só foi observada nos lisímetros R1 &#40;25 mmol&#41;, R2 &#40;35 mmol&#41; e R5 &#40;3 mmol&#41;, sendo os três com umidade inicial de 80&#37;. Em R1 e R2, observou-se elevadas concentrações de ácido acético, de 21.500 e 17.000 mg&#47;L, respectivamente, provavelmente devido à ocorrência de homoacetogênese. Sob temperatura termofílica, especialmente em R5, observou-se consumo de hidrogênio, e produção de etanol &#40;2.300 mg&#47;L&#41; e metanol &#40;5.600 mg&#47;L&#41;. Na condição de 80&#37; de umidade &#40;R1, R2, R5, R6&#41;, verificou-se maiores percentuais de remoção de papel e atividade fermentativa mais acentuada, ao passo que abaixo de 80&#37;, o desenvolvimento microbiano foi desfavorecido, independente da temperatura. Verificou-se consumo muito reduzido de papel e baixas concentrações de AOVs e álcoois para R3, R4, R7 e R8, todos com 50&#37; umidade. Em R9 e R10, operados a 45 &#176;C e 65&#37; de umidade, também verificou-se produção atenuada de AOVs e álcoois, com ausência de hidrogênio. Por meio do DCC, observou-se efeito estatisticamente significativo da umidade do papel na produção de hidrogênio, ácido acético e etanol. Em relação à temperatura, verificou-se efeito positivo estatisticamente significativo na produção de hidrogênio e ácido acético. Por fim, para a massa de papel não se verificou nenhum efeito sobre as respostas analisadas. Os gêneros de bactérias mais abundantes foram: Prevotella no fluido de rúmen in natura &#40;F.N.&#41; Dysgonomonas no fluido de rúmen enriquecido e em R2 &#40;35&#176;C&#41;, Thermicanus em R5 &#40;55&#176;C&#41; e Phaeospirillum em R9 &#40;45&#186;C&#41;. A umidade foi o parâmetro mais determinante para promover a hidrólise e fermentação do papel; a temperatura foi a principal variável de influência na estrutura das comunidades microbianas dos lisímetros, confirmada pelas diferentes rotas metabólicas observadas sob temperatura mesofílica e termofílica; e os rendimentos de produção dos compostos não foram influenciados pela massa de papel adicionada aos lisímetros. / This study evaluated the production of compounds of biotechnological interest and potential energy vectors from office paper in lysimeters &#40;20L&#41;, using a microbial consortium purified from rumen fluid. A central composite design &#40;CCD&#41; was performed to verify the influence of three independent variables on paper conversion to hydrogen and other organic compounds in bench lysimeter. The tested variables were: mass of paper &#40;x1: 500g, 750g and 1000g&#41;, moisture content &#40;x2: 50&#37;, 65&#37; and 80&#37;&#41;, and incubation temperature &#40;x3: 35&#176;C, 45&#176;C and 55&#176;C&#41;. The dependent variables of CCD were production of hydrogen &#40;Y1: mmol&#41;, acetic acid &#40;Y2: mg&#47;L&#41;, ethanol &#40;Y3:mg&#47;L&#41; and metanol &#40;Y4:mg&#47;L&#41;. For monitoring the lysimeters in relation to paper hydrolysis and fermentation, analyses of biogas &#40;H2, N2, CO2 and CH4&#41; and the organic compounds&#39; concentrations in the leachate, such as, total sugars, chemical oxygem demand, volatile organic acids &#40;VOA&#39;s&#41; and alcohols were conducted during operation. Alcalinity, pH and total solids content of the leachate were also monitored. Massive sequencing of rRNA 16S &#40;Illumina&#41; was carried out for identification of the microorganisms of the in natura rumen fluid, the purified consortium, and those collected from lysimeters R2, R5 and R9. Hydrogen production was detected only in lysimeters R1 &#40;25 mmol&#41;, R2 &#40;35 mmol&#41; and R5 &#40;3 mmol&#41;, all of them operated with 80&#37; of moisture content. In R1 and R2, high concentrations of acetic acid, of 21.500 and 17.000, respectively, were due to the likely occurrence of homoacetogenesis. Under thermophilic temperature, especially R5, the hydrogen production was detected in low quantity, and the highlight was the production of ethanol and methanol, with concentrations around 2.300 and 5.600 mg&#47;L, respectively. At 80&#37; moisture condition &#40;R1, R2, R5, R6&#41;, high percentages of paper removal and sharp fermentative activity were observed. However, at lower moisture conditions, the microbial growth was unfavored, independent of the temperature. Low paper consumption and reduced concentrations of OVA&#39;s and alcohols were detected in R3, R4, R7 and R8, all of them operated with 50&#37; of moisture content. In R9 and R10, operated at 45&#176;C and 65&#37; of moisture, there was also attenuated production of VOA\'s and alcohols, with absence of hydrogen. According to CCD statistical analysis, paper moisture content had positive effect statistically significative on hydrogen, acetic acid and etanol production. The temperature had positive effect on hydrogen and acetic acid production. And the mass of paper dit not have effect statistically significative for any dependent variables. The most abundant bacterial genus was: Prevotella in the in natura rumen fluid &#40;F.N.&#41; Dysgonomonas in the purified consortium and R2 &#40;35 oC&#41;, Thermicanus in R5 &#40;55&#176;C&#41; and Phaeospirillum in R9 &#40;45&#176; C&#41;. In conclusion, moisture content was the main parameter to promote paper hydrolysis and fermentation; temperature was the principal variable that influenced the structure of microbial community, confirmed by the different metabolic route observed under mesophilic and thermophilic conditions; and the production yields of the compounds were not influenced by the mass of paper added to the lysimeters.

In this thesis the structure and hydration of small organic and amphipilic compounds adsorbed at the air-liquid interface, have been studied using the nonlinear optical technique Vibrational Sum Frequency Spectroscopy (VSFS). The second order nature of the sum frequency process makes this technique particularly surface sensitive and very suitable for interfacial studies, as molecules at the surface can be distinguished even in the presence of a vast excess of the same molecules in the bulk. Particular emphasis was given to the surface water structure and how it is affected by the presence of small model compounds such as acetic acid and formic acid, and also non-ionic surfactants with sugar based and ethylene oxide based polar headgroups. Understanding the structure of water at these interfaces is of considerable fundamental importance, and here VSFS provided unique information. Upon addition of tiny amounts of these surface active compounds, the ordered surface structure of water was found to be significantly perturbed, as revealed by the changes observed in the characteristic spectroscopic signature of the dangling OH bond of water molecules, which vibrate free in air and are present in the top monolayer. Dramatic differences between the different compounds were also observed in the bonded OH region, providing a valuable insight into the hydration of polar groups at interfaces. Additionally, by employing different polarization combinations of the laser beams involved in the sum frequency process, information about the different water species present at the surface and their average orientation were extracted. In particular an unusual state of water was found with a preferred orientation in a non-donor configuration in close proximity to the hydrophobic region formed by the hydrocarbon tails of the surfactant molecules. The conformation and orientation of the different adsorbates were also characterized, targeting their specific vibrational frequencies. Noteworthy is the orientation of the fluorocarbon chain of ammonium perfluorononanoate (APFN), which in contrast to the hydrocarbon chains of the other surfactant molecules studied, remained constant over a wide range of surface densities. This behaviour was also observed for the anionic headgroup of sodium dodecyl sulphate (SDS). Other interesting findings were the formation of a cyclic dimer bilayer at the surface of concentrated aqueous solutions of acetic acid and the water structuring effect induced by poly(ethylene-oxide) headgroups, in spite of being themselves disordered at the air-liquid interface.

In der Hefe Yarrowia lipolytica führen Mutationen im GPR1-Gen zu Essigsäuresensitivität. Die Deletion dieses Genes hat demgegenüber keinen Effekt auf den Phänotyp. In dieser Arbeit wurde das Gpr1-Protein näher charakterisiert. Es zeigte sich, dass GPR1-Mutantenstämme wesentlich schneller Acetat akkumulierten als der Wildtyp. Außerdem konnte bestetigt werden, dass Gpr1p ein integrales Membranprotein ist. Mittels Ortspezifischer Analyse wurden verschiedene funktionelle Bereiche untersucht. Das Protein unterliegt zudem einer Phosphorylierung/Dephosphorylierung. Auf der Grundlage der dargelegten Ergebnisse wurde ein Funktionsmodell für Gpr1p erstellt.