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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.
31

Feeding Strategy Development For Benzaldehyde Lyase Production By Recombinant Escherichia Coli Bl21

Levent, Hande 01 June 2008 (has links) (PDF)
This study focuses on the molasses based complex medium design for benzaldehyde lyase production by recombinant E. coli BL21 and development of a feeding strategy based on the designed complex medium. For this purpose, firstly, the effects of molasses were investigated in laboratory scale bioreactors. As E. coli BL21 was not able to utilize sucrose, molasses was pretreated and hydrolyzed to fructose and glucose. Thereafter, effect of pretreated molasses concentration was investigated in the range of 16 to 56 kg m-3 by batch-bioreactor experiments / and the highest cell concentration and benzaldehyde lyase activity were obtained as CX=5.3 kg m-3 and A=1617 U cm-3, respectively, in the medium containing 7.5 kg m-3 glucose and 7.5 kg m-3 fructose. Then, different feeding strategies were developed to produce efficient cells with high concentration and BAL activity. In the first strategy, after 10 hours of batch-cultivation with molasses based medium having 7.5 kg m-3 glucose and 7.5 kg m-3 fructose concentration, based on the airflow rate, pretreated molasses was fed to the system. When air flow rate decreased considerably, fed was given to the system that results in increase in glucose and fructose concentration in the medium to 2.5 kg m-3. At the end of the process, the highest cell concentration obtained was CX=7.4 kg m-3. The maximum activity was reached at 20th hour as A=2360 U cm-3. On the other hand, as air flow variation only demonstrated the absence of glucose not fructose, a second strategy, based on the detection of the fructose and glucose concentrations during the process, was applied. In this strategy when glucose and fructose were depleted, fed was given to the system that results in increase in glucose and fructose concentration in the medium to 2.5 kg m-3 / and the highest BAL activity was obtained as 2370 U cm-3 at t= 26 h where the cell concentration was 7.5 kg m-3. At the last strategy, when glucose and fructose were depleted, fed was given to the system that results in increase in CGlucose=1.5 kg m-3 and CFructose=1.5 kg m-3 in the production medium to decrease the accumulation of acetic acid. By this strategy highest cell concentration was obtained as 8.04 kg m-3 at t=24 h and the highest BAL activity was 2315 U cm-3. These strategies could be accepted having the same BAL activity with little distinctions. However, cell concentration of the last one was higher than others and also the lowest amount of carbon source was used. Thus, last one could be chosen as the most favorable strategy.
32

Exponential Feeding Strategy Development For Benzaldehyde Lyase Production By Recombinant Escherichia Coli

Taspinar, Hatice 01 August 2010 (has links) (PDF)
In this study, the aim was to investigate the effects of exponential feeding strategy on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21. For this purpose, the effects of medium components were investigated to optimize the initial medium composition of the fed-batch fermentations. For the batch bioreactor operations, the highest cell concentration and BAL activity were achieved in a media containing 30 g L-1 pretreated molasses, and 5 g L-1 (NH4)2HPO4 as 5.07 g L-1, and 1611 U ml-1 at t=8 h, respectively. Thereafter, in order to increase the cell growth and BAL production while avoiding acetate accumulation, fed-batch bioreactor operations were conducted with exponential feeding at different specific growth rates namely, 0.1 h-1 (mu-0.1), 0.15 h-1 (mu-0.15), and 0.2 h-1 (mu-0.2), and a combined exponential and constant feeding (mu-0.2+) strategy. In the experiments, 9 hours of batch-wise operation with the optimized production medium was followed by a fed-batch operation phase using the pre-determined exponential feeding profiles and for mu-0.2+ operation after 10 hours of exponential feeding as mu-0.2, where the feed rate was kept constant at 21.6 g h-1. Additionally, the plasmid stability was investigated using the feeding method of mu-0.2+ operation with antibiotics in the feed solution, and it was observed that the plasmid was stable. Among the three exponential feeding conditions, the highest cell concentration and BAL activity were determined in
33

Photobiological Hydrogen Production From Sugar Beet Molasses

Sagir, Emrah 01 February 2012 (has links) (PDF)
The main aim of this study was to investigate biological hydrogen production from sucrose and molasses by purple non-sulphur bacteria (PNS). The hydrogen production capacities of four different PNS bacteria (Rhodobacter capsulatus (DSM 1710), Rhodobacter capsulatus YO3 (Hup-), Rhodopseudomonas palustris (DSM 127) and Rhodobacter sphaeroides O.U.001 (DSM 5864)) were tested on sucrose and molasses. The photobiological hydrogen production were performed in 50 ml and 150 ml small scale photobioreactors, in batch mode. The produced hydrogen quantities, bacterial growth profiles and pH of the media were recorded through the photobiological hydrogen production processes. Organic acids and sucrose consumption rates were determined by HPLC during the experiments. The maximum hydrogen productivitiy of 0.78 (mmol/lc.h) and 0.55 (mmol/lc.h) was obtained by R. palustris (DSM 127) on sucrose and molasses, respectively. Secondly, co-cultivation of these bacterial strains was studied. The maximum hydrogen productivity by co-cultivation of R. sphaeroides O.U.001 (DSM 5864) and R. palustris (DSM 127) was found as 1.0 (mmol/lc.h).
34

Urea-molasses based supplements for multipurpose buffaloes /

Thu, Nguyen Van. January 2000 (has links)
Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2000. / Errata tipped in. Includes bibliographical references.
35

The effects of artificial and natural sweeteners on various physiological systems

Rahiman, Farzana January 2011 (has links)
This study aimed to investigate the effects of commercially available natural (sugar cane molasses, white sugar and brown sugar) and artificial (Canderel™, Equal™, Natreen™, Sweetex™, Splenda™ and Swheet™) sweeteners on various physiological systems. The artificial sweeteners tested in this study may be categorised into their respective groups based on their primary ingredient. The brands Canderel™ and Equal™ contain aspartame, Natreen™ and Sweetex™ consist of saccharin and Splenda™ and Swheet™ are composed of sucralose. The inclusion of artificial or natural sweeteners in the human diet has been continually debated and their implication in the development of certain diseases has raised concern regarding their safe use. Therefore, it is necessary that these food products be subjected to a battery of tests to determine adverse effects on human health.
36

Valorization of vinasse as broth for biological hydrogen and volatile fatty acids production by means of anaerobic bacteria

Sydney, Eduardo Bittencourt 25 July 2013 (has links) (PDF)
Vinasse is the liquid waste removed from the base of sugarcane ethanol distillation columns at a ratio of 12-15 liters per liter of alcohol, resulting in an estimated production of approx. 350 billion liters in 2012/2013 in Brazil. Vinasse has a low pH and high chemical oxygen demand, which can cause land desertification when indiscriminately used as fertilizer. Also, underground water contamination is being observed in some regions. We evaluated the potential of vinasse as nutrient source for biohydrogen and volatile fatty acids production by means of anaerobic consortia. Two different vinasse-based media were proposed, using sugarcane juice or molasses as carbon source, and were compared to fermentation in a sucrosesupplemented medium. Pure cultures (4) and consortia (7) were cultured in the propose media and evaluated for volatile fatty acids (VFAs) and biohydrogen production. The consortium LPBAH1, originated from faeces of fruit bat, was selected for fermentation of vinasse supplemented with sugarcane juice and resulted in a higher H2 yield of 7.14 molH2/molsucrose and hydrogen content in biogas of approx. 31% after process optimization. Similarly, the optimized process using the consortium LPBAH2, originated from a lake of a dairy farm, resulted in 3.66 molH2/molsucrose and 32.7% hydrogen content in biogas. The proposed process is of great importance for giving a more rational destination to vinasse and expanding Brazilian energy matrix, reducing the dependence of fossil fuels.
37

Estudo comparativo das caracteristicas sensoriais do rum e da cachaça

Magnani, Bruna Dias [UNESP] 30 June 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-30Bitstream added on 2014-06-13T19:29:45Z : No. of bitstreams: 1 magnani_bd_me_arafcf.pdf: 297954 bytes, checksum: 1db499851fb3045fd3c4c2f670edf4e9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Ministério da Ciência, Tecnologia e Inovação (Mcti) / Tendo em vista diminuir eventuais dúvidas em relação à identidade da cachaça brasileira, cuja exportação tem aumentado consideravelmente nos últimos anos, foi objetivo do presente trabalho estabelecer as diferenças sensoriais entre o rum e a cachaça, aguardentes oriundas da cana-de-açúcar, porém distintas. Nesse sentido, foi realizado um estudo comparativo entre amostras de rum e de cachaça obtidas em laboratório sob condições praticamente idênticas, visando estabelecer seus perfis sensoriais e descrever as similaridades e diferenças entre essas bebidas. Assim, quatro amostras, sendo uma de aguardente de melaço, outra de cachaça e mais duas envelhecidas, sendo uma de rum e outra de cachaça envelhecida, tiveram seus perfis sensoriais determinados por Análise Descritiva Quantitativa (ADQ), por uma equipe de 7 julgadores treinados e selecionados de acordo com seu poder discriminativo, reprodutibilidade dos julgamentos e consenso com a equipe. Para descrever e comparar os perfis sensoriais das diferentes amostras foram levantados e quantificados 17 atributos sensoriais. Os dados obtidos foram submetidos à análise de variância (ANOVA), testes de média de Tukey e análise de componentes principais (ACP). Os resultados revelaram haver diferenças significativas (p ≤ 0,05) entre as características sensoriais das amostras e os dois primeiros componentes principais explicaram juntos 98,49% (ACP) das variações entre as amostras em relação aos seus atributos sensoriais. Os atributos que contribuíram para a diferenciação do rum e da cachaça envelhecida foram cor dourada, corpo, turbidez, aroma amadeirado, sabor madeira, sabor adocicado e viscosidade, enquanto que as amostras de aguardente de melaço e cachaça sem envelhecer foram diferenciadas pelos atributos aroma metálico, sabor metálico e pungência. / In order to reduce fortuitous doubts about the identity of Brazilian cachaça, whose export has increased considerably in recent years, it was goal of this study to establish sensory differences between rum and cachaça , spirits from the sugar cane, distinct however. Therefore, it was realized a comparative study among samples of rum and cachaça obtained in laboratory through practically identical conditions, to establish their sensory profiles and describe the similarities and differences between these beverages. Thus, four samples, one of molasses spirit and another of cachaça, and more two aged, which were, one of rum and another of aged cachaça had their sensory profiles determined by Quantitative Descriptive Analysis (QDA) conducted by a panel of 7 trained panelists and selected according to their discriminatory potential, reproducibility of trials and consensus with the panel. To describe and compare the sensory profiles of the different samples were developed and quantified 17 sensory attributes. The obtained data were submitted to analysis of variance (ANOVA), Tukey tests and Principal Components Analysis (PCA). The results revealed significant differences (p ≤ 0,05) about the sensory characteristics of spirits and the first principal component and the second principal component explained together 98.49% (PCA) of variations among the samples on their sensory attributes. The attributes that contributed to the differentiation of rum and aged cachaça were golden color, body appearance, turbidity, wood aroma, wood flavor, sweet taste and viscosity, while the samples of molasses spirit and non-aged cachaça were differentiated by attributes metallic aroma, metallic taste and pungency chemestetic. The results showed that the process of aging provided higher intensity of favorable sensory attributes for aged cachaça.
38

Qualidade do álcool produzido a partir de resíduos amiláceos da agroindustrialização da mandioca

Bringhenti, Lizandra [UNESP] 27 January 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-01-27Bitstream added on 2014-06-13T20:52:16Z : No. of bitstreams: 1 bringhenti_l_me_botfca.pdf: 411319 bytes, checksum: af3a1ca0db941f12654bf420dfe195fa (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Neste trabalho fez-se uma avaliação da utilização dos resíduos da agroindustrialização da mandioca como fonte de carbono para fermentação alcoólica, buscando um etanol, que possua qualidades adequadas para uso na indústria alimentícia. No sentido de promover uma alternativa viável, tanto tecnologicamente como economicamente, traçou-se um planejamento experimental que minimizasse os custos. Preocupou-se também, com a sustentabilidade ambiental do processo, pois a produção de álcool etílico pelo método aqui proposto, acena como uma alternativa para que o resíduo gerado, na indústria da mandioca, passe ao status de co-produto, gerando para a indústria não só receita como todos os benefícios mercadológicos de uma indústria limpa. O resíduo utilizado foi o amiláceo pré-hidrolizado que após o processo de fermentação foi destilado e teve seu produto separado e analisado. Desenvolveu-se uma coluna de destilação com recheio de vidro, para operação contínua a fim de estabelecer uma planta pré-piloto, onde ocorram os processos de hidrólise, fermentação e destilação. O substrato escolhido foi submetido a diversos ensaios e, o etanol obtido foi avaliado utilizando metodologias analíticas de derivatização. Para suprir as leveduras alcoólicas dos requisitos nutricionais necessários à sua manutenção durante o processo de fermentação, adicionou-se concentrações crescentes de mel residuário de sacarose aos substratos amiláceos previamente hidrolisados, nas proporções de 5, 10, 15 e 20% . Estas soluções foram padronizadas buscando manter a mesma concentração de carbono orgânico e na etapa subseqüente foram tratadas com enzimas amilolíticas para sacarificação completa. Após o inóculo com leveduras Saccharomyces cerevisiae, as fermentações foram... / In this study an evaluation of the residue from the agricultural industrialization of cassava root is aimed. The main goal of this evaluation was towards the potential use of the root as a carbon source to the ethanol production via fermentation. The ethanol obtained must have characteristics good enough to be used in the food industry. Keeping in mind that, nowadays, industrial process must be sustainable and also economically feasible, an experimental scheme was designed. If the second goal may be proved, the first one appears immediatelly; due to promote an alternative use for a residue that otherwise may impact the environment. The experiment begins with the pre-hydrolysed amylaceous that is a by-product from the production of cassava flour. This starch was submited to fermentation under optimized conditions, the wine resultant went trough destilation, the final product was separated and analised. A destilation column, containing glass pearls, was designed in order to integrate a pilot project that may work in a process of continuos operation. This pilot plant was designed in order to achieve the process of hydrolysis, fermentation and destilation. The chosen substrate was then submited to various tests at diverse conditions and the ethanol obtained was evalueted trhough analytical methods with derivatization. In order to optimize the fermentation process by giving to the yeast better conditions of development, molasses, from the sucrose production, was added. The additions were of 5, 10, 15 and 20 %. These solutions were standardized in order to keep the same organic carbon content and after this were submited to a treatment with amylolitc enzymes. This treatment goal was to promote a complete saccharification...(Complete abstract, click electronic access below)
39

Exigências nutricionais e operacionais para a produção de etanol pela levedura IQ-Ar/45-1 a partir do melaço em batelada alimentada

Silva, Leonardo de Almeida Ferreira e [UNESP] 26 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T19:17:19Z : No. of bitstreams: 1 silva_laf_me_araiq.pdf: 881872 bytes, checksum: 1ed668293818af00e17546ddfe67a5f2 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os resultados descritos neste trabalho para a produção de etanol utilizando-se a levedura IQ-AR/45-1, forneceram informações sobre os melhores suplementos nutricionais e melhor tamanho de inóculo para a fermentação em batelada alimentada. Dadas as variações na composição do melaço e o uso de uma nova levedura, faz-se necessário o estudo de suas exigências nutricionais em processos fermentativos. Experimentos preliminares em batelada simples mostraram que a adição de DAP diminuiu o tempo de fermentação, estimulou o acúmulo da biomassa e produção de etanol enquanto o ZnSO4.7H2O diminuiu o tempo da fermentação, e aumentou o acúmulo de etanol elevando a produtividade. A adição de MgSO4.7H2O produziu mais etanol, melhorou o rendimento alcoólico e a produtividade. Estes resultados obtidos em batelada simples foram transferidos para o sistema em batelada alimentada. A melhor vazão do melaço 20 % em ART foi de 0,40 mL.min-1 para um volume final de trabalho de 100,0 mL. O aumento da temperatura de fermentação de 34 ºC para 37 ºC em meio suplementado com DAP e ZnSO4.7H2O ou DAP e MgSO4.7H2O diminuiu o tempo da fermentação e a biomassa produzida, porém, com menor rendimento e maior produtividade de etanol. O tamanho do inóculo foi estudado com meio suplementado a 34ºC. As melhores condições foram obtidas no processo em batelada alimentada a 34ºC no qual foi utilizado melaço clarificado com ácido sulfúrico e uma quantidade de inóculo de (23,7±0,1) g.L-1 que levou a um tempo de fermentação de 5 horas. Nestas condições, o rendimento alcoólico foi de (79,1±0,7) % e a produtividade de (16,17±0,56) g.L-1 .h-1 / The results of the fermentative processes for ethanol production using the yeast IQ-AR/45-1, provided information about the best nutritional supplementation and inoculum size for the batch fermentation. Due to the differences in the sugarcane molasses and the use of a new yeast strain, it was necessary to study the nutritional requirements of the new yeast. Previous experiments in batch fermentation showed that the DAP addition reduced the fermentation time, enhanced the biomass and ethanol production while the ZnSO4.7H2O reduced the fermentation time and increased both the ethanol production and productivity. The addiction of MgSO4.7H2O to the molasses increased the ethanol yield and enhanced the productivity. These results obtained in batch cultures were assayed in fed-batch fermentation. Using 20 % molasses (TRS), the best flow was 0.40 mL.min-1 for a final working volume of 100.0 mL. When molasses supplemented with DAP and ZnSO4.7H2O or DAP and MgSO4.7H2O was used in the fed-batch experiments, the raise in the temperature from 34 ºC to 37 ºC led to decreases in the fermentation time, production of biomass, and ethanol yield followed by increases in ethanol productivity. The best inoculum size to the ethanol fermentation was (23.7±0.1) g.L-1 which led to a yield of (79.1±0.7) % and productivity of (16.17±0.56) g.L-1 .h-1
40

Qualidade do álcool produzido a partir de resíduos amiláceos da agroindustrialização da mandioca /

Bringhenti, Lizandra, 1973- January 2005 (has links)
Orientador: Cláudio Cabello / Banca: Waldemar Gastoni Venturini Filho / Banca: Simone Damasceno / Resumo: Neste trabalho fez-se uma avaliação da utilização dos resíduos da agroindustrialização da mandioca como fonte de carbono para fermentação alcoólica, buscando um etanol, que possua qualidades adequadas para uso na indústria alimentícia. No sentido de promover uma alternativa viável, tanto tecnologicamente como economicamente, traçou-se um planejamento experimental que minimizasse os custos. Preocupou-se também, com a sustentabilidade ambiental do processo, pois a produção de álcool etílico pelo método aqui proposto, acena como uma alternativa para que o resíduo gerado, na indústria da mandioca, passe ao status de co-produto, gerando para a indústria não só receita como todos os benefícios mercadológicos de uma indústria limpa. O resíduo utilizado foi o amiláceo pré-hidrolizado que após o processo de fermentação foi destilado e teve seu produto separado e analisado. Desenvolveu-se uma coluna de destilação com recheio de vidro, para operação contínua a fim de estabelecer uma planta pré-piloto, onde ocorram os processos de hidrólise, fermentação e destilação. O substrato escolhido foi submetido a diversos ensaios e, o etanol obtido foi avaliado utilizando metodologias analíticas de derivatização. Para suprir as leveduras alcoólicas dos requisitos nutricionais necessários à sua manutenção durante o processo de fermentação, adicionou-se concentrações crescentes de mel residuário de sacarose aos substratos amiláceos previamente hidrolisados, nas proporções de 5, 10, 15 e 20% . Estas soluções foram padronizadas buscando manter a mesma concentração de carbono orgânico e na etapa subseqüente foram tratadas com enzimas amilolíticas para sacarificação completa. Após o inóculo com leveduras Saccharomyces cerevisiae, as fermentações foram...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this study an evaluation of the residue from the agricultural industrialization of cassava root is aimed. The main goal of this evaluation was towards the potential use of the root as a carbon source to the ethanol production via fermentation. The ethanol obtained must have characteristics good enough to be used in the food industry. Keeping in mind that, nowadays, industrial process must be sustainable and also economically feasible, an experimental scheme was designed. If the second goal may be proved, the first one appears immediatelly; due to promote an alternative use for a residue that otherwise may impact the environment. The experiment begins with the pre-hydrolysed amylaceous that is a by-product from the production of cassava flour. This starch was submited to fermentation under optimized conditions, the wine resultant went trough destilation, the final product was separated and analised. A destilation column, containing glass pearls, was designed in order to integrate a pilot project that may work in a process of continuos operation. This pilot plant was designed in order to achieve the process of hydrolysis, fermentation and destilation. The chosen substrate was then submited to various tests at diverse conditions and the ethanol obtained was evalueted trhough analytical methods with derivatization. In order to optimize the fermentation process by giving to the yeast better conditions of development, molasses, from the sucrose production, was added. The additions were of 5, 10, 15 and 20 %. These solutions were standardized in order to keep the same organic carbon content and after this were submited to a treatment with amylolitc enzymes. This treatment goal was to promote a complete saccharification...(Complete abstract, click electronic access below) / Mestre

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