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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Probiotic lactobacilli as a soy yogurt starter culture - microbiological, chemical and sensory analyses

Wang, Chia-Lin, January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 116-131). Also available on the Internet.
62

Influence of variations in time and temperature of incubation on the growth of and fermentation by Lactobacillus helveticus and Streptococcus thermophilus

Peppler, Henry J. January 1937 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1937. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 58-59).
63

Isolation and characterization of nonstarter Lactobacillus spp. in Swiss cheese and assessment of their role on Swiss cheese quality

Kocaoglu-Vurma, Nurdan A., January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xiv, 111 p.; also includes graphics (some col.). Includes bibliographical references (p. 104-111). Available online via OhioLINK's ETD Center.
64

Röntgenstrukturanalyse der R-spezifischen Alkoholdehydrogenase aus Lactobacillus brevis bei 0.99 A Auflösung und röntgenkristallographische Untersuchungen an der D-Aminosäureoxidase aus Trigonopsis variabilis

Müller, Jörg. January 2000 (has links) (PDF)
Köln, Universiẗat, Diss., 2000.
65

Hochdruckinduzierte Genexpression bei Bakterien

Scheyhing, Carsten Heiko. January 2002 (has links) (PDF)
München, Techn. Universiẗat, Diss., 2003.
66

A study on the role of probiotic lactobacillus rhamnosus GG on gastric mucosal damages in rats /

Lam, Kai-Yee. January 2006 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2006. / Also available online.
67

Détection radiométrique rapide des Lactobacilles dans la bière et le moût en fermentation.

Salaün, Maryvonne, January 1900 (has links)
Th. doct.-ing--Nancy, I.N.P.L., 1978.
68

Lactobacilos productores de bacteriocinas aislados de quesos artesanales provenientes de Lima y provincias

Cristóbal Delgado, Ruth Liliana, Cristóbal Delgado, Ruth Liliana January 2008 (has links)
Con la finalidad de obtener bacterias ácido lácticas productoras de bacteriocinas se recolectaron 33 muestras de quesos artesanales provenientes de Lima y provincias y se aislaron 341 cepas de lactobacilos según los procedimientos establecidos por el Manual de Bergey. Las especies de lactobacilos aisladas con mayor frecuencia fueron Lactobacillus casei 56 % (191) y Lactobacillus plantarum 35.8 % (122). Sólo el 16.42 % (56/341) de los aislados presentaron actividad bacteriocinogénica frente a Lactobacillus acidophilus ATCC 4356. Los sobrenadantes de los cultivos bacteriocinogénicos se ajustaron el pH a 6.5 para descartar la acción de ácidos orgánicos, además se determinó el péroxido de hidrógeno por acción de la catalasa. La constitución bioquímica de las bacteriocinas presentes en los sobrenadantes fue determinada enzimáticamente utilizando pronasa E, a -amilasa y lipasa. El 53 % (30) de las bacteriocinas fueron de naturaleza lipoproteica, 25 % (14) glicolipoproteica, 13 % (7) glicoproteica y 9 % (5) solamente proteica. Por otro lado, los sobrenadantes fueron sometidos a tratamientos térmicos de 60, 80 y 100 °C, a pH 4, 7 y 9, y a temperaturas de conservación de 4, 15 y 32 °C y se encontró que la termoestabilidad fue de 60 a 80 °C, el pH óptimo de 4 a 7 y la temperatura óptima de conservación de 4 a 32 °C. Las bacteriocinas presentes en los sobrenadantes de los diferentes aislados inhibieron el crecimiento de cepas de Bacillus cereus UA05, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 10536, Salmonella typhimurium ATCC 14028, Salmonella choleraesuis ATCC 10708, Shigella sonnei ATCC 9290 y Pseudomonas aeruginosa ATCC 9027. Sin embargo, Listeria innocua UP01 fue resistente. El aislado identificado como Lactobacillus plantarum LM1 produjo la bacteriocina con los mejores parámetros fisicoquímicos experimentados y además presentó un amplio espectro de inhibición contra los microorganismos indicadores evaluados. Palabras Clave: bacterias ácido lácticas, bacteriocinas, lactobacilos, Lactobacillus plantarum, quesos artesanales / The aim of this study was to get bacteriocin – producing lactic acid bacteria. For the purpose of this study, thirty three samples of artisanal cheeses from Lima and provinieses were collected, and three hundred and forty one strains of lactobacilli were isolated according to the procedures established by Bergey’s Manual. The most frequently isolated species were Lactobacillus casei 56% (191) and Lactobacillus plantarum 35.8% (122). Only 16.42% (56/341) of the isolates showed bacteriocinogenic activity against Lactobacillus acidophilus ATCC 4356. The supernatants of bacteriocinogenic cultures were adjusted to pH 6.5 to rule out the action of organic acids, and it was determined the presence of hydrogen peroxide by the assay with catalase. The biochemical constitution of the bacteriocins present in the supernatants was determined using enzymatically pronase E, a - amylase and lipase. The 53% (30) of bacteriocins was of lipoproteinaceous nature, 25% (14) of glycolipoproteinaceous nature, 13% (7) of glycoproteinaceous nature, and 9% (5) only of proteinaceous nature. On the other hand, the supernatants were exposed to various heat treatments at 60, 80, and 100°C, to pH variation at 4, 7, and 9, and to storage temperatures at 4, 15 and 32°C, and it was found that the thermostability of bacteriocins was found from 60 to 80°C, the optimum pH was from 4 to 7, and the optimum storage temperature was from 4 to 32°C. The bacteriocins present in the supernatants of the different isolates inhibited the growth of Bacillus cereus UA05, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 10536, Salmonella typhimurium ATCC 14028, Salmonella choleraesuis ATCC 10708, Shigella sonnei ATCC 9290 and Pseudomonas aeruginosa ATCC 9027. However, Listeria innocua UP01was resistant. The isolate identified as Lactobacillus plantarum LM1 produced the bacteriocin with the best physicochemical parameters, and showed a broad spectrum of inhibition against the indicator microorganisms. Key words: Lactic acid bacteria, bacteriocins, lactobacilli, Lactobacillus plantarum, artisanal cheeses. / Tesis
69

Biotransformação de resíduos da carcinicultura em produtos de alto valor agregado / Shrimp waste biotransformation in high value added products

Ximenes, Júlio César Martins January 2015 (has links)
XIMENES, Júlio César Martins. Biotransformação de resíduos da carcinicultura em produtos de alto valor agregado. 2015. 131 f. Tese (doutorado em biotecnologia)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-04-05T19:00:26Z No. of bitstreams: 1 2016_tese_jcmximenes.pdf: 2037197 bytes, checksum: 1c3eea2a55ca400b3d0e6b8b6a881ea1 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-23T18:05:00Z (GMT) No. of bitstreams: 1 2016_tese_jcmximenes.pdf: 2037197 bytes, checksum: 1c3eea2a55ca400b3d0e6b8b6a881ea1 (MD5) / Made available in DSpace on 2016-05-23T18:05:00Z (GMT). No. of bitstreams: 1 2016_tese_jcmximenes.pdf: 2037197 bytes, checksum: 1c3eea2a55ca400b3d0e6b8b6a881ea1 (MD5) Previous issue date: 2015 / Shrimp farming is the fastest growing segment in aquiculture in the world. In Brazil, Ceara is the largest producer with 50 % of all production. Approximately 40 % of the shrimp weight is considered waste as the head, tail and bark, generating large amounts of waste that must be properly discarded. Thus, the reuse of shrimp farming waste through biotechnological resources emerges as an innovative alternative to reduce environmental pollution caused by that activity. This study aimed to perform a biotechnological process based on bacterial consortium capable to fermenting shrimp waste turning them into a liquor used in feed for Nile tilapia (Oreochromis niloticus) post-larvae in sex reversal process. Lactic acid bacteria strains used were identified by sequencing of the 16S rRNA, rpoA and pheS genes and biochemical tests involving the ability to ferment carbohydrates. For the consortium selection some studies were performed such as chemical kinetics use of Monod, Andrews and Levenspiel mathematical models to determine possible types of inhibition. To evaluate the liquor potential from fermentation as a supplement in feed for tilapia post-larvae were prepared feed diets with liquor inclusions of 15, 30 and 45 %, by monitoring the water quality and temperature parameters, dissolved oxygen, pH, salinity, total ammonia nitrogen, nitrite, nitrate and orthophosphate in addition to growth performance. For that, we evaluated the survival rate, specific growth rate, weight and length gain, feed conversion factor and selection by size. This work identified lactobacilli strains named Lact 7, Lact 8, Lact 9 and Lact 14 as belonging to Lactobacillus plantarum species, Lact 6 as L. futsaii and Lact 11 as Pediococcus acidilactici. As to fermentation kinetic parameters, Lact 6, Lact 7 and Lact 14 strains showed the best results and there was no evidence of inhibition by substrate or product. During shrimp heads fermentation Lact 6 and Lact 14 consortium produced the highest lactic acid yields, about 100 g.L-1. Liquor inclusions of 15 and 30 % provided the best results for survival, weight and length gain, specific growth rate and biomass of Nile tilapia post-larvae. Feed conversion did not differ between treatments, being slightly higher in treatment with 30 % of liquor. Nitrite, nitrate and orthophosphate increased significantly over the weeks, although concentrations have remained at acceptable levels and other parameters remained within the recommended during the tilapia development. The data from this study showed that it is technologically feasible to transform shrimp farming waste into added-value products by lactic fermentation. The resulting liquor fermentation, rich in protein, minerals and pigments can be incorporated in a proportion of up to 30% in tilapia feed, without causing, any impact the development of tilapia post-larvae and thus bringing economic benefits and proper disposition of shrimp farming waste. / A carcinicultura é o segmento da aquicultura que mais cresce no mundo. No Brasil, o Ceará é o maior produtor com 50% de toda a produção. Sabe-se que aproximadamente 40% do peso do camarão sejam considerados resíduos, como a cabeça, a cauda e a casca, gerando grandes quantidades de resíduos que devem ser descartados adequadamente. Assim, o reaproveitamento de resíduos da carcinicultura através de recursos biotecnológicos surge como uma alternativa inovadora para reduzir a poluição ambiental causada por essa atividade. O presente estudo teve por objetivo aperfeiçoar um processo biotecnológico baseado na utilização de consórcio bacteriano capaz de fermentar os resíduos da carcinicultura transformando-os em líquor para ser utilizado na alimentação de pós-larvas de Tilápia do Nilo (Oreochromis niloticus) em fase de reversão sexual. As linhagens de bactérias láticas utilizadas foram identificadas através do sequenciamento dos genes RNAr 16S, rpoA e pheS e por testes bioquímicos envolvendo a habilidade de fermentar carboidratos. Para a seleção do consórcio foram realizados estudos de cinética química, modelos matemáticos de Monod, Andrews e Levenspiel para determinar possíveis tipos de inibição do processo de fermentação lática de cabeças de camarão. Para avaliar o potencial do líquor resultante da fermentação como suplemento na alimentação de pós-larvas de tilápia foram confeccionadas rações com inclusões de líquor na proporção de 15, 30 e 45 %, monitorando-se a qualidade da água e os parâmetros de temperatura, oxigênio dissolvido, pH, salinidade, nitrogênio amoniacal total, nitrito, nitrato e ortofosfato, além do desempenho zootécnico. Para tanto, foram avaliados a taxa de sobrevivência, taxa de crescimento específico, ganho em peso e comprimento, fator de conversão alimentar e seleção por tamanho. Como resultados deste trabalho foram identificadas linhagens de lactobacilos nomeadas Lact7, Lact8, Lact9 e Lact14 como pertencentes a espécie Lactobacillus plantarum, Lact6 como L. futsaii e Lact11 como Pediococcus acidilactici. Quantos aos parâmetros cinéticos da fermentação, as linhagens Lacts6, Lact7 e Lact14 apresentaram os melhores resultados e não houve indícios de inibição pelo substrato ou produto. Durante a fermentação das cabeças de camarão o consórcio formado pelas linhagens Lact6 e Lact14 produziram os mais altos rendimentos de ácido lático, cerca de 100 g.L-1. Inclusões do líquor resultante da fermentação lática dos resíduos de camarão nas proporções de 15 e 30 % proporcionaram os melhores resultados para sobrevivências, ganho em peso e comprimento, taxa de crescimento específico e biomassa de pós-larvas de Tilápia do Nilo. A conversão alimentar não diferiu entre os tratamentos. Nitrito, nitrato e ortofosfato aumentaram significativamente ao longo das semanas, embora as concentrações tenham se mantido em níveis aceitáveis, bem como os demais parâmetros se mantiveram dentro do recomendado durante o desenvolvimento da tilápia. Os dados desse estudo mostraram que é tecnologicamente viável transformar resíduos da carcinicultura em produtos de valor agregado por fermentação lática. O líquor resultante da fermentação, rico em proteínas, pigmentos e minerais pode ser incorporado na proporção de até 30% na ração, sem causar nenhum impactado no desenvolvimento de pós-larva da tilápia e portanto, trazendo benefícios econômicos e destinação apropriada para resíduos da carcinicultura.
70

Mikrobiologická charakteristika probiotických preparátů

Horáková, Kateřina January 2007 (has links)
No description available.

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