Determination of kinetics data of the pretreatment of sugarcane bagasse with alkaline hydrogen peroxide and subsequent enzymatic hydrolysis

Orientadores: Aline Carvalho da Costa, Rubens Maciel FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: O objetivo deste trabalho foi obter dados experimentais da cinética de pré-tratamento com peróxido de hidrogênio alcalino e da cinética de hidrólise enzimática posterior do bagaço de cana-de-açúcar. O pré-tratamento foi realizado nas condições determinadas como ótimas para este processo com concentrações de 8% (m/m) de bagaço, 11% (v/v) de peróxido de hidrogênio e pH igual a 11,5. Os dados experimentais para o pré-tratamento foram obtidos nas temperaturas de 25, 45 e 65ºC, analisando-se os teores de lignina, celulose e hemicelulose em função do tempo de pré-tratamento. À 25ºC houve menor deslignificação em relação à 65ºC, mas não houve degradação da celulose. A hidrólise enzimática foi realizada com bagaço pré-tratado usando celulase de T. reesei e ß-glicosidase de A. Niger a 50ºC. No primeiro ciclo de experimentos, a massa de bagaço foi variada entre 1 e 5 g com volume reacional fixo em 100 mL, correspondendo às concentrações de 1 e 5% de bagaço (m/m). As concentrações de celulase e ß-glicosidase foram mantidas fixas em 500 FPU/L e 500 CBU/L, respectivamente. A carga enzimática fixa dificultou a transferência de massa e adsorção das enzimas, por isto, resultados menos satisfatórios foram observados para os ensaios com maior concentração de bagaço. Experimentos adicionais foram realizados fixando-se a massa de bagaço em 3% (m/m) e variando-se as concentrações de celulase e ß-glicosidase de acordo com um planejamento 22 + configuração estrela. Os resultados reafirmaram que a ação das enzimas sobre o substrato ocorre de forma sinérgica. Nos experimentos para avaliação da hidrólise enzimática, as concentrações de celobiose, glicose, xilose e arabinose são mostradas em função do tempo.Abstract: The objective of this work was to obtain experimental data of the kinetics of pretreatment with alkaline hydrogen peroxide and of the kinetics of the subsequent enzymatic hydrolysis of sugarcane bagasse. The pretreatment was performed in the conditions determined as optimal for this process with concentrations of 8% (w/w) of bagasse, 11% (v/v) of hydrogen peroxide and pH of 11,5. The experimental data were obtained at temperatures of 25, 45 e 65°C, analyzing the concentrations of lignin, cellulose and hemicellulose were analyzed as functions of pretreatment time. At 25°C was observed lower delignification when compared to the 65°C, but not occurred degradation of cellulose. The enzymatic hydrolysis was performed with pretreated bagasse using celulase from T. reesei and ß- glicosidase from A. Niger at 50 ºC. In the first round of experiments, bagasse mass was varied from 1 to 5 g with fixed reactional volume of 100 mL, corresponding to concentrations of 1 to 5% of bagasse (w/w). The concentrations of celulase and ß- glucosidade were fixed in 500 FPU/L and 500 CBU/L, respectively. The enzyme loading fixed difficult the transfer of mass and the adsorption of the enzymes, therefore, less satisfactory results were observed for tests with higher concentration of bagasse. Additional experiments were performed fixing bagasse mass at 3% (w/w) and varying celulase and ß- glucosidade concentrations according to a 22 + star configuration factorial design. The results confirmed that the action of enzymes on the substrate occurs in a synergistic way. In the experiments for enzymatic hydrolysis, the concentrations of celobiose, glucose, xylose and arabinose are shown as functions of time. Key-words: Hydrogen peroxide, pretreatment, hydrolysis, sugarcane bagasse.MestradoDesenvolvimento de Processos QuímicosMestre em Engenharia Químic

Efeitos da própolis na proliferação de fibroblastos em lesões cutâneas de ratos

O presente estudo teve por objetivo verificar o efeito tópico da própolis na proliferação de fibroblastos e a disposição e volume de fibras colágenas presentes durante o processo de reparo tecidual. Foram utilizados ratos wistar, machos, divididos em dois grupos: Grupo Controle (CC) n=16 lesão tratada com creme nãoiônico; Grupo Própolis (PP) n=16 lesão tratada com creme não-iônico + Própolis 10%. Nos 4º, 7°, 14° e 21° dias de tratamento foram sacrificados 4 animais de cada grupo em câmara de gás carbônico. O tecido lesionado foi coletado e fixado em formalina a 10% por 48 horas, incluído em álcool a 70%, fixado em parafina e depositado em lâminas para análise histológica. Os resultados demonstraram um aumento no número de fibroblastos e também maior e melhor disposição de fibras colágenas no grupo PP em relação ao grupo CC. Assim, as evidências obtidas no estudo mostraram que o efeito da própolis na aceleração do processo de reparo tecidual não é somente por sua ação antiinflamatória, conforme diversos estudos demonstram, mas também por sua ação direta sobre a proliferação de fibroblastos, acelerando a reversão de fibrócito para fibroblasto, e, consequentemente favorecendo a síntese e deposição de fibras colágenas, melhorando o reparo tecidual e reduzindo o tempo de cicatrização

Neotropical xenarthrans: a dataset of occurrence of xenarthran species in the Neotropics.

International audienceXenarthrans—anteaters, sloths, and armadillos—have essential functions forecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosys-tem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts withdomestic dogs, these species have been threatened locally, regionally, or even across their fulldistribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths.Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae(3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data onDasypus pilo-sus(Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized,but new genetic studies have revealed that the group is represented by seven species. In thisdata paper, we compiled a total of 42,528 records of 31 species, represented by occurrence andquantitative data, totaling 24,847 unique georeferenced records. The geographic range is fromthe southern United States, Mexico, and Caribbean countries at the northern portion of theNeotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regardinganteaters,Myrmecophaga tridactylahas the most records (n=5,941), andCyclopessp. havethe fewest (n=240). The armadillo species with the most data isDasypus novemcinctus(n=11,588), and the fewest data are recorded forCalyptophractus retusus(n=33). Withregard to sloth species,Bradypus variegatushas the most records (n=962), andBradypus pyg-maeushas the fewest (n=12). Our main objective with Neotropical Xenarthrans is to makeoccurrence and quantitative data available to facilitate more ecological research, particularly ifwe integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, andNeotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure,habitat loss, fragmentation effects, species invasion, and climate change effects will be possiblewith the Neotropical Xenarthrans data set. Please cite this data paper when using its data inpublications. We also request that researchers and teachers inform us of how they are usingthese data

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data