• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 2
  • 1
  • Tagged with
  • 10
  • 10
  • 5
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Identification de bactéries lactiques isolées de l'écosystème mammaire bovin et caractérisation de leur potentiel inhibiteur contre des pathogènes associés à la mammite / Identification of lactic acid bacteria isolated from bovine udder ecosystem and its characterisation as potential inhibitors against mastitis-associated pathogens / Identificaçao de bacterias laticas isoladas do ecossistema mamario bovino e caracterizacao de seu potencial inibidor contra patogenos associados à mastite

Seridan de Assis, Bianca 12 March 2015 (has links)
Les mammites ont un impact économique considérable dans les régions productrices de lait de divers pays, dont le Brésil et la France. Elles constituent la première cause de consommation d’antibiotiques dans les élevages laitiers qui doivent répondre à une forte demande sociétale pour une agriculture consommant moins d’intrants et plus respectueuse de l’environnement et du bien-être animal. Il y a donc une réelle nécessité de trouver des outils alternatifs efficaces pour le contrôle des mammites bovines infectieuses. Ce travail de thèse a eu comme objectif la recherche de souches de bactéries lactiques (BL) ayant des capacités inhibitrices de l'infection mammaire, pouvant être utilisées comme probiotiques mammaires. Pour cela, 278 (165 en France et 113 au Brésil) souches bactériennes ont été isolées à partir de lait et de la superficie et du canal du trayon de vaches laitières et 10 souches non-redondantes de BL ont été identifiées et caractérisées en fonction de leurs propriétés deparoi et de production de composés inhibiteurs avant d'évaluer leurs interactions avec des agents pathogènes responsables de mammites et/ou avec les cellules hôtes dans un modèle de cellules épithéliales mammaires bovines (CEMb). Deux souches de Lactobacillus brevis et une de Lactobacillus plantarum ont montré une bonne capacité d’adhésion aux cellules épithéliales ce qui pourrait inhiber l'invasion par Staphylococcus aureus, un pathogène majeur responsable de mammites, et de stimuler la production de cytokines pro- et anti-inflammatoires par les CEMb. D'autres tests d'interaction avec des lign / Mastitis causes huge economic losses in the dairy sector both in Brazil and France. They also are the first cause of antibiotic consumption in the dairy farms. There is thus a need for new alternatives to antibiotics to control infectious mastitis. In this thesis work, we isolated 278 (165 in France and 113 in Brazil) bacterial strains from bovine milk and teat canal, and identified 10 non-redundant lactic acid bacteria (LAB) strains that were further tested as potential mammary probiotic candidates. LAB strains were tested for their surface properties and production of inhibitory compounds and then evaluated for their interactions with Staphylococcus aureus and Escherichia coli, two major mastitis pathogens, or with bovine mammary epithelial cells (bMEC), in vitro. Some LAB strains (Lactobacillus brevis e Lactobacillus plantarum) presented inhibitory capacity against S. aureus adhesion and internalisation and were shown to stimulate the production of pro- and anti-inflammatory cytokinin bMEC. Other interaction tests with bMEC showed that Lactococcus lactis V7 was able to significantly inhibit bMEC invasion by Escherichia coli and S. aureus. Although the inhibitory mechanism was not elucidated, Lactococcus lactis V7 showed promising capacities in terms of mammary probiotic potential with, notably, the ability to modulate the immune response of E. coli-infected bMEC by modifying the expression of inflammatory cytokine genes. In this work, several LAB strains were identified in the milk and teat canal microbiota. We showed that L. brevis, L. plantarum and Lactococcus lactis
2

Ante partum determination of lactate in amniotic fluid /

Wiberg-Itzel, Eva. January 2005 (has links)
Lic.-avh. Stockholm : Karolinska institutet, 2005.
3

Composição bromatológica, perfil fermentativo, populações microbianas, consumo e digestibilidade de silagem de soja com inoculante e, ou, melaço em pó / Chemical composition, fermentative profile, microbial populations, intake and digestibility of soybean silage with inoculant and, or, molasses powder

Rosa, Lilian Oliveira 19 February 2010 (has links)
Made available in DSpace on 2015-03-26T13:54:55Z (GMT). No. of bitstreams: 1 texto completo.pdf: 836498 bytes, checksum: 07fbd08593c521ae0b188fb7b6535dca (MD5) Previous issue date: 2010-02-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work involved two trials. In the first trial was evaluated the chemical composition; the fermentative profile and the microbial populations in soybean silage. The soybean was harvested at the R6 stage of development and submitted of treatments, before ensilage: 1- without additive (control), 2- with inoculant (I), 3- I plus molasses powder and 4- molasses powder. It was used the inoculant SIL ALL C4 (Alltech, Brasil). At treatments with molasses it was used 2,5% on fresh matter. The material was ensilaged in laboratory silos with 2-Kg of capacity and opened with 1, 3, 7, 14, 28 and 56 days of fermentation in a complete randomized design, with three replicates. There was effect (P<0.05) of additive and period under the DM and CP, while lignin did not influenced (P>0.05) by factors analyzed. On the other hand, it was observed effect (P<0.05) of additives x periods to others variable analyzed. The acids lactic, acetic and butyric concentrations was influenced (P<0.05) by additives and fermentation periods. About the pH was observed reduction 0.3443, 0.3868, 0.3355 e 0.3815 units per day of fermentation to control; with inoculant; I plus molasses powder and that with molasses silages, respectively. It was registered greatest acid lactic bacteria population to 28 days of fermentation, at silage with inoculant. The additions of inoculant, associated or not to molasses powder, on soybean ensilage improve the silage fermentative profile. At second trial was evaluated the intake and total apparent digestibility of nutrients in sheep. The soybean was submitted at same treatments of trial one and ensiladed in plastics barrels 150 L of capacity. The roughage:concentrate used was 90:10, based on the dry matter, using the ground as maize grain concentrate. It was used 20 adult sheep, male, without race set, castrated, with an average weight of 60 kg, distributed in a randomized complete block design, with five replicates. The intake of nutrients did not influenced (P>0.05) by treatments. It was effect of treatments (P<0.05) on NFC total apparent digestibility. Soybean silage with inoculant associated or not to molasses powder did not influence the intake and the total digestibility of nutrients in sheep. / Este trabalho envolveu dois experimentos. No experimento 1, foram avaliados a composição bromatológica; o perfil fermentativo e as populações microbianas em silagens de soja. A soja foi colhida no estádio de desenvolvimento R6 e submetida aos seguintes tratamentos, antes da ensilagem: sem aditivo (controle); com inoculante (I); I + melaço em pó e melaço em pó. Utilizou-se o inoculante SIL ALL C4 da Alltech do Brasil. Nos tratamentos com melaço foram aplicados 2,5% na base da matéria natural. O material foi ensilado em silos laboratoriais de PVC com 2 kg de capacidade e abertos com 1, 3, 7, 14, 28 e 56 dias de fermentação. Adotou-se um arranjo fatorial 4 X 6 (4 aditivos X 6 períodos de fermentação) no delineamento inteiramente casualizado, com três repetições. Observou-se efeito de aditivos e de período de fermentação (P<0,05) para os teores de matéria seca e proteína bruta, enquanto que o teor de lignina não foi afetado (P>0,05) pelos fatores estudados. Por outro lado, observou-se efeito (P<0,05) da interação aditivo x período de fermentação para as demais variáveis. As concentrações dos ácidos lático, acético e butírico foram influenciadas (P<0,05) por aditivos e períodos de fermentação. Para o pH das silagens, foram estimadas reduções de 0,3443; 0,3868; 0,3355 e 0,3815 unidades por dia de fermentação para as silagens controle, tratadas com inoculante, I + melaço e aquelas com melaço, respectivamente. Foi registrada máxima população de bactérias do ácido lático aos 28 dias de fermentação, na silagem com inoculante. A adição de inoculante, associada ou não ao melaço em pó, por ocasião da ensilagem da soja melhora o perfil fermentativo das silagens. No experimento 2, avaliaram-se o consumo e a digestibilidade aparente total dos nutrientes de silagens de soja, em ensaio com ovinos. A soja foi submetida aos mesmos tratamentos do experimento 1 e ensilada em tambores plásticos com 150 L de capacidade. A relação forragem: concentrado foi de 90:10, na base da matéria seca, utilizando-se o milho grão moído como concentrado. Foram utilizados 20 ovinos adultos, sem raça definida, castrados, com peso vivo médio de 60 kg, distribuídos em um delineamento em blocos casualizados, com cinco repetições. O consumo dos nutrientes não foi afetado (P>0,05) pelas dietas experimentais. Houve efeito de dietas sobre a digestibilidade aparente total dos carboidratos não fibrosos (P<0,05). Silagens de soja com inoculante associadas ou não ao melaço, não alteram o consumo nem a digestibilidade aparente total dos nutrientes em ovinos.
4

Avaliação do potencial antioxidante de bebidas fermentadas de origem láctea preparadas com Lactobacillus acidophilus: uma revisão sistemática / Evaluation of antioxidant potential of lactic fermented beverages prepared with Lactobacillus acidophilus: A sistematic review

Antunes, Andressa Regina 03 February 2017 (has links)
Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2017-08-31T13:37:40Z No. of bitstreams: 2 Andressa Regina Antunes.pdf: 1269867 bytes, checksum: d72378812bab26dd3a8c0c8918a70c93 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-08-31T13:37:40Z (GMT). No. of bitstreams: 2 Andressa Regina Antunes.pdf: 1269867 bytes, checksum: d72378812bab26dd3a8c0c8918a70c93 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-03 / Introduction: The damage caused by the formation of free radicals in the body of animals and humans has presented significative results, once the physiopathology of different types of sickness, such as diabetes, hypertension, atherosclerosis, cancer, among others, follows the binding with the action of these highly reactive components. To reduce the effects caused by them, alternatives in medication are being developed, in order to act as therapeutic adjuvants or prophylactics, like in the case of lactic beverages fermented with probiotic microorganisms. This occurs due to the advantages obtained by both the intrinsic nutrients of these beverages, as well as the microorganisms that forms them, beyond the products of their fermentation. A bacteria species with probiotic properties well-known by their antioxidant potential is the Lactobacillus acidophilus, that is used in fermentation processes for the production of fermented milk, mainly with functional aspects. Objective: Gathering evidences about the antioxidant aspect shown in fermented lactic beverages that contain Lactobacillus acidophilus, by “in vitro” and “in vivo” experimental design tests, besides, evaluating the evidences regarding the other characteristics related to the manufacture of these beverages, like the physical-chemical, microbiologic, antioxidants and methodologic aspects, with the intention of clarifying if these probiotic properties really interfere with the antioxidant aspects of the samples, as well as with the other important aspects for the production of fermented lactic beverages. Material and Methods: A systematic review was done in the data bases: Medline, Cochrane, Scopus, Science Direct, Scifinder, Web of Science, Scielo and Agrícola, considering the following criteria: “antioxidant activity”, “oxidative stress”, “Lactobacillus acidophilus”, “lactic beverage”, “fermented milk”, “yogurt”, “in vitro techniques” and “in vivo”, related with the boolean operators “AND” and “OR”, moreover the manual search for studies on this area that could be of interest. The articles gathered through all the research sources had their titles and abstracts evaluated according to the pre-established inclusion criteria being, basically, the presence of Lactobacillus acidophilus in the constitution of fermented milks, whether isolated or in association with other bacteria, and that had their contents evaluated about their antioxidant aspect. The studies that followed these criteria had their contents fully read. Subsequently, all data of interest were extracted from the included articles, evaluated and compared with literature data for control samples (pure milk) or samples of similar microbiological composition, and also compared with data from brazilian legislation, when available. Results and Discussion: Through the entire data bases searched, 1751 articles were retrieved and read in terms of title and summary. Out of these, 36 articles were selected and fully read, and from them, eight articles followed the inclusion criteria for “in vitro” tests. For “in vivo” tests, six articles were fully read, and considering that only one of them followed the inclusion criteria, it was not possible, therefore, to develop a comparative research for this methodologic design, considering the selected search strategy. Thus, from these eight articles related to “in vitro” experiments, a total of 17 samples of interest were comprehended in the microbiologic constitution requirements, showing at least the presence of Lactobacillus acidophilus, which included three fermented milks (Subgroup A = 17.65%), eight acidophilic milks (Subgroup B = 47.06%) and three yogurts (Subgroup C = 35.29%). From the total declared cellular materials, 66.67% of these were characterized as intracellular content free of cells, being the rest, cellular content without breaking. Regarding the microbiologic constitution, it was possible to verify that, after the intentional presence of Lactobacillus acidophilus, the second most frequent used microorganism was Streptococcus thermophilus, followed by Lactobacillus bulgaricus. Regarding the evaluation of antioxidant activity, the analytic technique used with more frequency was that which evaluates the eliminatory capacity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, followed by the method of elimination of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical. Based on the profile of antioxidant activity, subgroup B was classified as being the best characterized, due to emcompass, in general, greater number of tests of antioxidant activity in relation to the others. In addition, when constituted by Lactobacillus acidophilus, almost all of the samples evaluated presented consistent results for the antioxidant activity. Conclusion: Based on the obtained results, the importance of association between different analytical methods for evaluation of antioxidant activity is emphasized, due to the greater precision of the recovered results and consequent scientific support given to the study. Besides, it could be verified that, when there is presence of the probiotic of interest in the constitution of the studied food, the antioxidant activity is enhanced, which leads to understand that in fact the microorganism has that characteristic. On the other hand, when in presence of other microorganisms, whether they are probiotic or not, the antioxidant activity is still increased, although not in a proportional way, leading to the understanding that only the presence of Lactobacillus acidophilus is able to provide sufficient antioxidant protection to food in which it is added. Thus, lactic fermented beverages that contain this probiotic could be consumed with the premise of antioxidant protection, mainly by individuals that suffer from sicknesses with physiopathologies related to oxidative stress. / Introdução: O dano causado pela formação de radicais livres no organismo de animais e humanos tem apresentado resultados significativos, uma vez que a fisiopatologia de diversos tipos de doenças, como diabetes, hipertensão, aterosclerose, câncer, entre outras, possui ligação com a ação destes compostos altamente reativos. Para a redução dos malefícios causados por eles, alternativas não medicamentosas estão sendo desenvolvidas, a fim de atuarem como adjuvantes terapêuticos ou profiláticos, como é o caso das bebidas lácteas fermentadas com microrganismos probióticos. Isso ocorre em função das vantagens obtidas tanto pelos nutrientes intrínsecos destas bebidas, bem como dos microrganismos que as constituem, além de seus produtos de fermentação. Uma espécie bacteriana com propriedade probiótica notadamente conhecida por seu potencial antioxidante é o Lactobacillus acidophilus, utilizado em processos fermentativos para a obtenção de leites fermentados, e preferencialmente com aspectos funcionais. Objetivo: Reunir evidências sobre o aspecto antioxidante apresentado por bebidas lácteas fermentadas em presença de Lactobacillus acidophilus, a partir de ensaios com desenhos experimentais “in vitro” e “in vivo”, além de avaliar as evidências a respeito das demais características vinculadas à fabricação destas bebidas, como os aspectos físico-químicos, microbiológicos, antioxidantes e metodológicos, com a intenção de esclarecer se o referido probiótico realmente interfere no aspecto antioxidante das amostras, bem como nos demais aspectos de interesse para a fabricação de leites fermentados. Material e Métodos: Foi realizada uma revisão sistemática nas bases de dados: Medline, Cochrane, Scopus, Science Direct, Scifinder, Web of Science, Scielo e Agrícola, considerando os seguintes termos de busca: “antioxidant activity”, “oxidative stress”, “Lactobacillus acidophilus”, “lactic beverage”, “fermented milk”, “yogurt”, “in vitro techniques” e “in vivo”, associados aos operadores booleanos “AND” e “OR”, além da busca manual por estudos na área que pudessem ser de interesse. Os artigos recuperados por meio de todas as fontes de busca tiveram os seus títulos e resumos avaliados de acordo com os critérios de inclusão preestabelecidos, sendo eles, basicamente, a presença de Lactobacillus acidophilus na constitução de leites fermentados, isolado ou em associação com outras bactérias, e que tiveram os seus conteúdos avaliados quanto ao aspecto antioxidante. Os estudos que atenderam a esses critérios tiveram os seus conteúdos lidos na íntegra. Na sequência, todos os dados de interesse foram extraídos dos artigos incluídos, avaliados e comparados com dados de literatura para amostras controle (leite puro) ou amostras de constituição microbiológica semelhante, e ainda, comparados com dados da legislação brasileira quando disponíveis. Resultados e Discussão: Por meio das bases de dados pesquisadas, 1751 artigos foram recuperados e lidos em termos de título e resumo. Desses, 36 artigos foram selecionados e tiveram seus conteúdos lidos na íntegra, e, a partir deles, oito artigos atenderam aos critérios de inclusão para estudos “in vitro”. Para estudos “in vivo”, seis artigos foram lidos na íntegra, sendo que apenas um deles atendeu aos critérios de inclusão, não sendo possível, portanto, o desenvolvimento de uma pesquisa comparativa para o referido desenho metodológico, considerando a estratégia de busca escolhida. Dessa forma, a partir dos oito artigos envolvendo experimentos “in v vitro”, um total de 17 amostras de interesse se enquadraram no requisito de constituição microbiológica, por apresentarem no mínimo a presença de Lactobacillus acidophilus, as quais incluíram três leites fermentados (Subgrupo A = 17,65%), oito leites acidófilos (Subgrupo B = 47,06%) e seis iogurtes (Subgrupo C = 35,29%). Do total de materiais celulares declarados, 66,67% deles foram caracterizados como conteúdo intracelular livre de células, sendo o restante, o conteúdo celular sem rompimento. Quanto à constituição microbiológica, foi possível verificar que, após a presença intencional de Lactobacillus acidophilus, o segundo microrganismo mais frequentemente utilizado foi Streptococcus thermophilus, seguido por Lactobacillus bulgaricus. No que se refere à avaliação da atividade antioxidante, a técnica analítica empregada com maior frequência foi aquela que avalia a capacidade eliminatória do radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), seguida pelo método de eliminação do radical 2,2'-azino-bis(3-ethylbenzothiazoline- 6-sulphonic acid) (ABTS). Com base no perfil de atividade antioxidante, o subgrupo B foi classificado como sendo o melhor caracterizado, em função de ter englobado, no geral, maior número de testes de atividade antioxidante em relação aos demais. Em adição, quando constituídas por Lactobacillus acidophilus, quase a totalidade das amostras avaliadas apresentaram resultados consistentes para a atividade antioxidante. Conclusão: Partindo dos resultados obtidos, enfatiza-se a importância da associação entre diferentes métodos analíticos para a avaliação da atividade antioxidante, devido à maior precisão dos resultados recuperados e consequente respaldo científico conferido ao estudo. Além disso, verifica-se que, quando a presença do probiótico de interesse se encontra na constituição do alimento estudado, a atividade antioxidante é exaltada, o que leva a entender que de fato o microrganismo apresenta tal característica. Por outro lado, quando em presença de outros microorganismos, probióticos ou não, a atividade antioxidante é ainda melhorada, mas não de forma proporcional, levando à compreensão de que apenas a presença de Lactobacillus acidophilus é capaz de fornecer proteção antioxidante suficiente ao alimento em que for acrescentado. Dessa forma, bebidas lácteas fermentadas em presença desse probiótico poderiam ser consumidas com a premissa de proteção antioxidante, principalmente por indivíduos acometidos pordoenças com fisiopatologias envolvidas com o estresse oxidativo.
5

Aspectos higiênico-sanitários, físico-químicos e microbiota lática de leite cru, queijo de coalho e soro de leite produzidos no Estado da Paraíba

Freitas, Wilma Carla de 29 September 2011 (has links)
Made available in DSpace on 2015-04-17T14:49:15Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1419809 bytes, checksum: 9b1c297f8a6dc2a2623ffb7fc7b76004 (MD5) Previous issue date: 2011-09-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The coalho cheese is a traditional product made in northeastern Brazil, is widely consumed in the state of Paraiba and knowledge of their indigenous microflora is of the fundamental importance. Thus, this study aim to: verify the microbiological and physical-chemistry characteristics of raw milk, whey and coalho cheese the three properties (A, B and C), respectively located in the regions of Paraiba and compare them with the legislation; to evaluate the profile of consumers of coalho cheese; isolate, characterize and identify lactic acid bacteria in these samples using two methods, comparing them and check the antimicrobial activity against these bacteria identified as Salmonella enterica, S. aureus and L. monocytogenes. Samples of raw milk and nine of cheese were submitted the following tests: standard plate count (SPC), the Most Probable Number (MPN) of total and thermotolerant coliforms, S. aureus, Salmonella; and analysis of pH, water activity, acid, protein, fat, total solids, nonfatty solids, fat in dry matter, humidity, ashes, chlorides and density. The samples of milk, whey and cheese, thermotolerant coliforms and S. aureus were present in numbers above the recommended level, indicating inadequate sanitary conditions of the raw milk and the final product. Regarding the physical-chemical analysis, was found high acidity in milk samples from the producers B and C and cheese samples were considered fat, high and very high humidity. The lactic acid bacteria counts of raw milk from producers B and C were in the order of 106 CFU/ mL in the whey and three producers of 107 CFU/mL, while cheese producer C obtained the highest counts (109 CFU/g). The 112 typical colonies of lactic acid bacteria were isolated and yours distribution of from the products were: Enterococcus, Lactococcus, Streptococcus and Leuconostoc. From a total of twenty isolates, twelve were identified by the API kit. The two methods used for comparison in the identification of genera, only 25% coincided and diverged with the majority of identifications performed by the second method of the Cogan et al., (1997). Of the twenty isolates, nineteen showed inhibition halos on three pathogenic bacteria, with inhibition zones 2 to 15 mm being the largest halos formed by Lactococcus lactis ssp lactis on S. enterica and S. aureus. However, the antimicrobial activity displayed by some lactic acid bacteria isolates suggest the possibility of its use against pathogens and can act as a barrier in the development of these micro-organisms and biological preservatives in coalho cheese. / O queijo de coalho é um produto tradicional do nordeste brasileiro, sendo amplamente consumido no estado da Paraíba, todavia o conhecimento da sua microbiota autóctone é de fundamental importância. Esta pesquisa teve como objetivos: avaliar as condições higiênico-sanitárias e físico-químicas de leite cru, queijo de coalho e soro de leite de três propriedades (A, B e C), situadas respectivamente nas mesorregiões do Agreste, Borborema e Sertão paraibanos e compará-los com os padrões da legislação; avaliar o perfil dos consumidores de queijo de coalho; isolar, caracterizar e identificar as bactérias láticas dessas amostras usando duas metodologias, comparando-as e verificar a atividade antimicrobiana dessas bactérias identificadas frente a Salmonella enterica, S. aureus e L. monocytogenes. Em nove amostras de leite, queijo coalho e de soro de leite, foram realizadas às seguintes análises: contagem de bactérias aeróbias mesófilas, NMP de coliformes totais e termotolerantes, contagem de S. coagulase positiva, pesquisa de Salmonella, umidade, proteína, lipídios, extrato seco total, sólidos não gordurosos, gordura no extrato seco, cinzas, acidez, pH, densidade e atividade de água. Nas amostras de leite, queijo e soro provenientes das três propriedades os coliformes termotolerantes e S. aureus estiveram presentes em números acima do recomendado, indicando condições higiênico-sanitárias insatisfatórias da matéria-prima e produto final. Nas análises físico-químicas, foi verificada acidez elevada nas amostras de leite dos produtores B e C e quanto à gordura e umidade as amostras de queijo de coalho foram consideradas queijos gordos, de alta a muito alta umidade. As contagens de bactérias láticas do leite cru dos produtores A, B e C foram de 104 a 106 UFC/mL, nas do soro dos três produtores na ordem de 107 UFC/mL, e as do queijo 106 (A e B), enquanto que o queijo do produtor C obteve as maiores contagens (109 UFC/g). Foram isoladas 112 colônias típicas de bactérias láticas das três amostras e os gêneros predominantes foram: Enterococcus, Lactococcus, Streptococcus e Leuconostoc. De um total de vinte isolados de queijo, doze foram identificadas pelo KIT API. As duas metodologias utilizadas para comparação na identificação dos gêneros coincidiu 25%, divergindo com a maioria das identificações realizadas pela metodologia segundo Cogan et al. (1997). Dos vinte isolados, dezenove apresentaram halos de inibição sobre as três bactérias patogênicas, com zonas de inibição de 2 a15 mm sendo os maiores halos formados por Lactococcus lactis ssp lactis sobre S. enterica e S. aureus. Entretanto, a atividade antimicrobiana revelada por alguns isolados de bactérias láticas sugerem a possibilidade de seu uso contra patógenos e podem atuar como uma barreira no desenvolvimento destes micro-organismos, bem como conservantes biológicos no queijo de coalho.
6

CaracterizaÃÃo molecular de bactÃrias Ãcido lÃticas com potencial tecnolÃgico para produÃÃo de queijo de coalho no Cearà / Molecular caracterization of lactic acid bacterias (lab with technological potential for production of coalho cheese in the CearÃ

Ana AmÃlia Martins de Queiroz 06 June 2008 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Queijo de Coalho à um dos produtos lÃticos mais consumidos no Nordeste do Brasil. No estado do CearÃ, sua produÃÃo à considerada tradicional e apresenta bastante significÃncia econÃmica e social. O queijo de Coalho à tradicionalmente feito com leite cru, o que representa um risco em potencial para a saÃde do consumidor, devido à possibilidade de veiculaÃÃo de microrganismos patogÃnicos. O processo de pasteurizaÃÃo do leite, alÃm de destruir os microrganismos patogÃnicos, reduz tambÃm as bactÃrias Ãcido lÃticas (BAL) que sÃo os microrganismos responsÃveis pelas propriedades sensoriais dos alimentos fermentados. AlÃm do mais, a substituiÃÃo das BAL endÃgenas por fermento lÃtico comercial tem levado a perdas nas propriedades sensoriais do queijo. Este trabalho teve por objetivo identificar, pela tÃcnica da ReaÃÃo em Cadeia da Polimerase (PCR), BAL dos gÃneros Lactococcus e Lactobacillus, previamente identificadas bioquimicamente, isoladas de leite, massa de queijo e queijos de Coalho artesanais produzidos no estado do CearÃ. Os 44 isolados selecionados apresentavam propriedades tecnolÃgicas de interesse para fabricaÃÃo de queijo de Coalho como: capacidade de acidificar o leite, baixa atividade proteolÃtica, capacidade de produÃÃo de aroma e capacidade de tolerÃncia ao NaCl na concentraÃÃo de 3%. As PCR identificaram 20,4% dos isolados como Lactococcus lactis subsp. lactis e 27,3% como Lactobacillus paracasei. Nenhum isolado de Lactobacillus plantarum teve sua identificaÃÃo confirmada pela tÃcnica molecular. Ao todo, 47,7% dos isolados foram confirmados pela PCR, assegurando que estes microrganismos podem ser usados na fabricaÃÃo de queijo de Coalho a partir de leite pasteurizado, mantendo as caracterÃsticas sensoriais tÃpicas deste produto. Este estudo mostra a importÃncia da implantaÃÃo de tÃcnicas moleculares aumentando a qualidade e a eficiÃncia na identificaÃÃo de microrganismos. / Coalho Cheese is one of the dairy products more consumed in Northeast of Brazil. In Cearà state, its fabrication is traditional and has social and economic importance. Traditionally, it is made with raw milk, which represents potential risk for consumers health due to the possibility of foodborne pathogens transmission. The milk pasteurization process eliminates pathogenic microorganisms, but also reduces the lactic acid bacterias (LAB) â the microorganism responsible for sensorial characteristics of fermented foods. Moreover, the substitution of indigenous LAB by commercial lactic ferment has led to losses in the sensorial properties of the cheese. This work aimed to identify, by Polymerase Chain Reaction (PCR), LAB of the genus Lactococcus and Lactobacillus, previously biochemical identified, isolated from milk, curd and traditional Coalho cheeses produced in the state of CearÃ. The forty-four strains selected presented interesting technological properties for the Coalho cheese manufacture: ability to acidify the milk, low proteolytic activity, ability to produce flavor and ability to tolerate 3% NaCl. The PCR identified 20,4% of the isolates as Lactococcus lactis subsp. lactis and 27,3% as Lactobacillus paracasei. No one Lactobacillus plantarum was identified by the molecular technique employed. A total of 47.7% of the isolates were confirmed by PCR, assuring that these microorganisms can be used for Coalho cheese manufacture made from pasteurized milk, preserving the typical characteristics of this product. This work shows the relevance of molecular approaches, increasing the quality and efficiency in the microorganisms identification.
7

Hydroxycarboxylic acid receptor 3 and GPR84: Two metabolite-sensing G protein-coupled receptors with opposing functions in innate immune cells

Peters, Anna, Rabe, Philipp, Liebing, Aenne-Dorothea, Krumbholz, Petra, Nordström, Anders, Jäger, Elisabeth, Kraft, Robert, Stäubert, Claudia 14 February 2022 (has links)
G protein-coupled receptors (GPCRs) are key regulatory proteins of immune cell function inducing signaling in response to extracellular (pathogenic) stimuli. Although unrelated, hydroxycarboxylic acid receptor 3 (HCA3) and GPR84 share signaling via Gαi/o proteins and the agonist 3-hydroxydecanoic acid (3HDec). Both receptors are abundantly expressed in monocytes, macrophages and neutrophils but have opposing functions in these innate immune cells. Detailed insights into the molecular mechanisms and signaling components involved in immune cell regulation by GPR84 and HCA3 are still lacking. Here, we report that GPR84-mediated pro-inflammatory signaling depends on coupling to the hematopoietic cell-specific Gα15 protein in human macrophages, while HCA3 exclusively couples to Gαi protein. We show that activated GPR84 induces Gα15-dependent ERK activation, increases intracellular Ca2+ and IP3 levels as well as ROS production. In contrast, HCA3 activation shifts macrophage metabolism to a less glycolytic phenotype, which is associated with anti-inflammatory responses. This is supported by an increased release of anti-inflammatory IL-10 and a decreased secretion of pro-inflammatory IL-1β. In primary human neutrophils, stimulation with HCA3 agonists counteracts the GPR84-induced neutrophil activation. Our analyses reveal that 3HDec acts solely through GPR84 but not HCA3 activation in macrophages. In summary, this study shows that HCA3 mediates hyporesponsiveness in response to metabolites derived from dietary lactic acid bacteria and uncovers that GPR84, which is already targeted in clinical trials, promotes pro-inflammatory signaling via Gα15 protein in macrophages.
8

Organische Linkermoleküle auf Basis natürlicher Hydroxycarbonsäuren zum Aufbau homochiraler poriger Festkörperstrukturen

Eißmann, Diana 02 September 2011 (has links)
Das Ziel dieser Arbeit bestand in der Synthese neuartiger homochiraler Molekülstrukturen, welche nach Konzepten des Crystal Engineering über ein starres Grundgerüst sowie koordinationsfähige Haftgruppen verfügen sollten. Unter Verwendung von Wein- und Milchsäure, als Vertreter der natürlich vorkommenden, enantiomerenreinen α-Hydroxycarbonsäuren, konnten die entsprechenden Derivate mit aromatischen und/oder acetylenischen Spacerelementen hergestellt und umfassend charakterisiert werden. Die synthetisierten Wein- und Milchsäureverbindungen sowie die sich von den jeweiligen Weinsäureestern ableitenden TADDOLe wurden außerdem auf ihre optische Aktivität, ihre Affinität gegenüber verschiedenen Lösungsmitteldämpfen, ihr Einschlussverhalten gegenüber achiralen und chiralen Lösungsmitteln sowie ihre Eignung als organische Linker bei der Synthese von metallorganischen Gerüststrukturen untersucht. Mittels Röntgeneinkristallstrukturanalyse konnten die Festkörperstrukturen einiger Derivate aufgeklärt und diese hinsichtlich ihrer Konformation verglichen werden.
9

Možnost zpracování glycerolové fáze z výroby bionafty / Possibilities of reprocessing of glycerol layer from the manufacture of bionaphta

Hýža, Bohumil January 2014 (has links)
The aim of this thesis was to introduce and apply the possibilities of using waste glycerol from biodiesel production and partly waste low-stiffen coolant from cars that could be applied in industry. At the beginning of the thesis is summarized biodiesel production and its world production. There is more developed biodiesel production in the Czech Republic and in the European Union and some European legal regulations and standards for biodiesel. Also described herein is a composition of biodiesel and the description of the technology of its production. In the theoretical section summarizes the physical and chemical properties of glycerol and there is also summarized the traditional use of glycerol as food, explosives, etc. There are also new procedures that were performed in the experimental part of the thesis. There are described the ion exchange mechanism, ion exchange resin properties and the properties of the acids and salts generated by neutralization with NaOH contained in the waste glycerol. Also is described herein the wood protection and properties of ethylene glycol coolants and properties of boroglycerol and boroglycol as protection for wood and mechanism of their preparation. Next is described the mechanism of dehydration of glycerol to acrolein and options which can perform the synthesis. In the experimental part, the pH of waste glycerol was measured, then was measured the exact amount of NaOH in the glycerol. There is also desribed cleaning of waste glycerol from NaOH using acidic cation exchange resins on columns, or by neutralization with oleic acid, lactic acid and CO2. Further syntheses were performed glycerol borate and ethylene glycol borate. Water amount in ethylene glycol and methanol with water amount in glycerol were found by distillation. Then were prepared boroglycol and boroglycerol. By the amount resulting from the amount of reaction water were observed reaction conditions H3BO3, Na2B4O7•10 H2O and glycerol. At the end was carried out experimental dilution resulting boroglycerol and boroglycol by ethanol, methanol, TMB. Finally, the diluted boroglycerol was deposited on wood. Dehydration of glycerol to acrolein under the catalytic action of KHSO4 was performed. The results are given all the results and discussed the possibility of using the knowledge gained in this work in the industry. In conclusion, there are listed the economic comparison using waste glycerol and crude oil as a raw material and also charts the development of oil prices in 40 years since 1970, and graph of the price of waste glycerol.
10

Možnosti zpracování odpadů glykolu a glycerolu na účelové látky / Possibilities of reprocessing of the glycol and glycerol waste into suitable materials

Hýža, Bohumil January 2014 (has links)
At the beginning of the thesis is summarized biodiesel production and its world production. There is more developed biodiesel production in the Czech Republic and in the European Union and some European legal regulations and standards for biodiesel. Also described herein is a composition of biodiesel and the description of the technology of its production. In the theoretical section summarizes the physical and chemical properties of glycerol and there is also summarized the traditional use of glycerol as food, explosives, etc. There are also new procedures that were performed in the experimental part of the thesis. Then, here are the proposed new procedures for processing waste glycerol and glycol, which were conducted in the experimental part of the thesis. There are described the ion exchange properties of the cation exchangers and also properties of salts generated by neutralization of NaOH in the waste glycerol with organic acids and CO2. There is also described wood protection, properties of ethylene glycol as coolant and properties of boroglycerols and boroglycols as protection for wood and mechanism of their preparation. Then there is described a mechanism of dehydration of glycerol to acrolein and options which can perform the synthesis. In the experimental part, the pH of waste glycerol was measured and then was measured the amount of NaOH in the waste glycerol. There is also desribed cleaning of waste glycerol from NaOH using acidic cation exchange resins on columns, or by neutralization with oleic acid, lactic acid and CO2. Further syntheses were performed glycerol borate and ethylene glycol borate. Water amount in ethylene glycol and methanol with water amount in glycerol were found by distillation. Then were prepared boroglycol and boroglycerol. By the amount resulting from the amount of reaction water were observed reaction conditions H3BO3, Na2B4O7•10 H2O and glycerol. At the end was carried out experimental dilution resulting boroglycerol and boroglycol by ethanol, methanol, TMB. Finally, the diluted boroglycerol was deposited on wood. Dehydration of glycerol to acrolein under the catalytic action of KHSO4 was performed. The results are given all the results and discussed the possibility of using the knowledge gained in this work in the industry. In conclusion, there are listed the economic comparison using waste glycerol and crude oil as a raw material and also charts the development of oil prices in 40 years since 1970, and graph of the price of waste glycerol. There is also discussed technological applicability of the methods used in practice.

Page generated in 0.0514 seconds