Academic literature on the topic 'Alcohol fermentation process'

The fuel ethanol industry is now making use of a very efficient process where virtually all sugar substrates are converted to ethanol. Nevertheless, some metabolic by-products excreted from Saccharomyces cerevisiae tend to reduce the ethanol yield. Of such, glycerol is the major one, accounting for about 5-10% relative to the amount of ethanol produced.<br>Glycerol plays an important role in maintaining the redox balance within the cells by oxidizing the cytosolic NADH under anaerobic conditions. It is also believed that it acts as an osmoprotectant and would be favourably produced in high osmotic pressure conditions.<br>In order to mitigate the production of glycerol, various aeration strategies were investigated in a single-stage continuous fermentation system. Oxygen dissolved in the fermentation medium put the yeast in aerobiosis, acted as an oxidizing agent and hence minimised the specific glycerol production by 36% as compared to a completely anaerobic fermentation.<br>This has hardly been reproduced in a more industrially relevant system using a multi-stage continuous fermentation process. Indeed, oscillations in the concentrations of the various metabolites over time made difficult the assessment of significant changes. Nevertheless, these findings open the door to further investigations in order to understand the effect of oxygen in continuous fermentations using very high gravity feeds, such as in the fuel ethanol industry.

Thesis (MScEng)--Stellenbosch University, 2012<br>ENGLISH ABSTRACT: Through many years of research, a number of production schemes have been developed for converting lignocellulosic biomass into transport fuels. These technologies have been assessed through a number of techno-economic studies for application in a particular context in terms of the technical and economic feasibility. However, previous studies using these methods have tended to lack vigour in various aspects. Either the energy efficiency of the processes were not maximised through adequate heat integration, or a competing technology which existed was not considered. From an economic perspective, the financial models would often lack the vigour to account for the risk and uncertainty that is inherent in the market prices of the commodities. This phenomenon is especially relevant for the biofuel industry that faces the full fledge of uncertainties experienced by the agricultural sector and the energy sector. Furthermore, from an environmental perspective, the techno-economic studies had often ignored the environmental impacts that are associated with biofuel production. Thus, a comparative study could have favoured an option due to its economic feasibility, while it could have had serious environmental consequences. The aim of this study was to address these issues in a South African context, where biofuels could be produced from sugarcane bagasse. The first step would be to modify an existing simulation model for a bioethanol scenario that operates with a Separate Hydrolysis and Fermentation (SHF process) configuration into a second processing scenario that operates with a Simultaneous Saccharification and Fermentation (SSF process) configuration using reliable experimental data. The second step was to ensure that the maximum energy efficiency of each scenario was realised by carrying out pinch point analysis as a heat integration step. In contrast to these biological models is the thermochemical model that converts bagasse to gasoline and diesel via gasification, Fischer-Tropsch synthesis and refining (GFT process). While there were no significant advances in technology concerning this type of process, the energy efficiency was to be maximised with pinch point analysis. The GFT process obtained the highest energy efficiency of 50.6%. Without the affects of pinch point technology, the efficiency dropped to 46%, which thus emphasises the importance of heat integration. The SSF had an efficiency of 42.8%, which was superior to that of the SHF at 39.3%. This resulted from a higher conversion of biomass to ethanol in the SSF scenario. Comparing the SHF model to an identical model found in literature that did not have pinch point retrofits, this study showed lower efficiency. This arose because the previous study did not account for the energy demands of the cold utility systems such as the cooling tower operation, which has been shown in this study to account for 40% of the electrical energy needs. The economic viability of all three processes was assessed with Monte Carlo Simulations to account for the risks that the fluctuations in commodity prices and financial indices pose. This was accomplished by projecting the fluctuations of these parameters from samples of a historical database that has been transformed into a probability distribution function. The consequences were measured in terms of the Net Present Value (NPV) and Internal Rate of Return (IRR) for a large number of simulations. The results of these variables were aggregated and were then assessed by testing the probability that the NPV<0, and that the IRR recedes below the interest rate of 12.64%. The investment was thus deemed unfeasible if these probabilities were greater than 20%. Both biological models were deemed profitable in terms of this standard. The probabilities were 13% for the SSF and 14% for the SHF. The GFT process however was deemed completely unfeasible because the probability that the NPV<0 was 78%. Given that the GFT process had the highest energy efficiency, this result arises mainly because the capital investment of 140,000USD/MWHHV of biomass energy input is to enormous for any payback to be expected. The environmental footprint of each process was measured using Life Cycle Assessments (LCAs). LCAs are a scientifically intricate way of quantifying and qualifying the effects of a product or process within a specified boundary. The impacts are assessed on a range of environmental issues, such as Global Warming, Acidification, Eutrophication and Human toxicity. Furthermore, if the project under concern has multiple output products, then the impacts are distributed between the output products in proportion to the revenue that each generates. The impacts were either relative to the flow of feedstock, which was 600MW of bagasse, or to the functional unit, which was the amount of fuel required to power a standard vehicle for a distance of 1 kilometre. In either case, the GFT scenario was the least burdening on the environmental. This was expected because the GFT process had the highest energy efficiency and the process itself lacked the use of processing chemicals. Relative to the feedstock flow, the SSF was the most environmentally burdening scenario due to the intensive use of processing chemicals. Relative to the functional unit, the SHF was the most severe due to its low energy efficiency. Thus, the following conclusions were drawn from the study:  The GFT is the most energy and environmentally efficient process, but it showed no sign of economic feasibility. iv  There is no significant difference in the economic and environmental evaluation of the SSF and SHF process, even though the SSF is considered to be a newer and more efficient process. The major cause of this is because the setup of the SSF model was not optimised.<br>AFRIKAANSE OPSOMMING: Deur baie jare van navorsing is ‘n aantal produksie-skemas vir die omskakeling van lignosellulose biomassa na vloeibarebrandstof ontwikkel. Hierdie tegnologië is geassesseer ten opsigte van die tegniese en ekonomiese haalbaarheid deur middel van tegno-ekonomiese studies in bepaalde tekste. Tog het hierdie vorige studies besliste beperkings gehad. Of die energie-doeltreffendheid van die proses is nie gemaksimeer deur voldoende hitte-integrasie nie, of 'n mededingende tegnologie wat bestaan is nie oorweeg nie. Vanuit 'n ekonomiese perspektief, was die finansiële modelle dikwels nie die omvattend genoeg om rekening te hou met die risiko en onsekerheid wat inherent is in die markpryse van die kommoditeite nie. Hierdie verskynsel is veral relevant vir die biobrandstof bedryf wat die volle omvang van onsekerhede ervaar waaraan die landbousektor en die energiesektoronderhewig is. Verder het die tegno-ekonomiese studies dikwels die omgewingsimpakte wat verband hou met biobrandstofproduksie geïgnoreer. Dus kon ‘n opsie deur die ekonomiese haalbaarheid bevoordeel word, ten spyte van die ernstige omgewingsimpakte wat dit kon inhou. Die doel van hierdie studie was om hierdie kwessies aan te spreek in 'n Suid-Afrikaanse konteks, waar biobrandstof uit suikerriet bagasse geproduseer kan word. Die eerste stap was om 'n bestaande simulasiemodel vir 'n bio-scenario wat met Afsonderlike Hidroliese en Fermentasie (SHF proses) stappe werk, te modifiseer vir 'n tweede verwerking scenario wat met 'n gelyktydige Versuikering en Fermentasie (SSF proses) konfigurasie werk. Die verandering is gedoen deur die gebruik van betroubare eksperimentele data. Die tweede stap was om te verseker dat elke scenario die maksimum energie-doeltreffendheid het, deur 'n hitte-integrasie stap, wat gebruik maak van “pinch-point” analise. In teenstelling met hierdie biologiese modelle, is daar die thermochemiese roete waar petrol en diesel van bagasse vervaardig word via vergassing, Fischer-Tropsch-sintese en rafinering (GFT proses). Daar was geen betekenisvolle vooruitgang in tegnologie vir hierdie proses nie, maar die energie-doeltreffendheid is gemaksimeer word deur energie-integrasie. Die GFT proses toon die hoogste energie-doeltreffendheid van 50,6%. Sonder die invloed van energie-integrasie het die doeltreffendheid gedaal tot 46%, wat dus die belangrikheid van hitte-integrasie beklemtoon. Die SSF het 'n effektiwiteit van 42,8% gehad, wat beter was as dié 39,3% van die SHF opsie. Hierdie hoër effektiwiteit wasas gevolg van die hoër omskakeling van biomassa na etanol in die SSF scenario. Die energie doeltreffendheid vir die SHF-model was laer as met 'n identiese model (sonder energie-integrasie) wat in die literatuur gevind wat is. Dit het ontstaan omdat die vorige studie nie 'n volledig voorsiening gemaak het met die energie-eise van die verkillingstelselsnie, wat tot 40% van die elektriese energie behoeftes kan uitmaak. Die ekonomiese lewensvatbaarheid van al drie prosesse is bepaal met Monte Carlo simulasies om die risiko's wat die fluktuasies in kommoditeitspryse en finansiële indekse inhou, in berekening te bring. Hierdie is bereik deur die projeksie van die fluktuasies van hierdie parameters aan die hand van 'n historiese databasis wat omskep is in 'n waarskynlikheid verspreiding funksie. Die gevolge is gemeet in terme van die netto huidige waarde (NHW) en Interne Opbrengskoers (IOK) vir 'n groot aantal simulasies. Die resultate van hierdie veranderlikes is saamgevoeg en daarna, deur die toets van die waarskynlikheid dat die NPV <0, en dat die IRR laer as die rentekoers van 12,64% daal, beoordeel. Die belegging is dus nie realiseerbaar geag as die waarskynlikhede meer as 20% was nie. Beide biologieseprosesse kan as winsgewend beskou word in terme van bostaande norme. Die waarskynlikhede was 13% vir die SSF en 14% vir die SHF. Aangesien die NHW van die GFT-proses onder 0 met ‘n waarskynlikheid van 78% is, is die opsie as nie-winsgewend beskou. Gegewe dat die GFT-proses die hoogste energie-doeltreffendheid het, is die resultaat hoofsaaklik omdat die kapitale belegging van 140,000 USD / MWHHV-biomassa energie-inset te groot is, om enige terugbetaling te verwag. Die omgewingsvoetspoor van elke proses is bepaal deur die gebruik van Lewens Siklus Analises (“Life Cycle Assessments”) (LCAS). LCAS is 'n wetenskaplike metodeom die effek van ‘n produk of proses binne bepaalde grense beide kwalitatief en kwantitatief te bepaal. Die impakte word beoordeel vir 'n verskeidenheid van omgewingskwessies, soos aardverwarming, versuring, eutrofikasie en menslike toksisiteit. Voorts, indien die projek onder die saak verskeie afvoer produkte het, word die impakte tussen die afvoer produkte verdeel, in verhouding tot die inkomste wat elkeen genereer. Die impak was met of relatief tot die vloei van roumateriaal (600MW van bagasse), of tot die funksionele eenheid, wat die hoeveelheid van brandstof is om 'n standaard voertuig aan te dryf oor 'n afstand van 1 kilometer. In al die gevalle het die GFT scenario die laagste belading op die omgewing geplaas. Hierdie is te verwagte omdat die GFT proses die hoogste energie-doeltreffendheid het en die proses self nie enige addisionele chemikalieë vereis nie. Relatief tot die roumateriaal vloei, het die SSF die grootse belading op die omgewing geplaas as gevolg van die intensiewe gebruik van verwerkte chemikalieë. Relatief tot die funksionele eenheid, was die SHF die swakste as gevolg van sy lae energie-doeltreffendheid.

Orientadores: Rubens Maciel Filho, Aline Carvalho da Costa<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica<br>Made available in DSpace on 2018-08-07T06:46:12Z (GMT). No. of bitstreams: 1 Mantovaneli_IvanaCristinaCordeiro_M.pdf: 4744367 bytes, checksum: 648b4b28d0ad3fff1bfeda9851005fc1 (MD5) Previous issue date: 2005<br>Resumo: A utilização do etanol como combustível tem muitas vantagens; ele tem competido economicamente com a gasolina e diversos outros combustíveis, substituindo-os em várias utilidades. Desta forma, existe um grande interesse em se otimizar todos os passos da produção de etanol. Apenas um conhecimento profundo da dinâmica do processo gera uma operação ótima, e este pode ser conseguido através de simulações realizadas usando um modelo preciso. Muitos modelos fenomenológicos foram desenvolvidos considerando condições industriais, mas estes só são válidos para condições específicas nas quais foram determinados, invalidando a predição do modelo em outras condições. Mudanças acontecem normalmente em uma unidade industrial e a re-estimação freqüente dos parâmetros do modelo é usualmente difícil e demorada. O objetivo deste trabalho é desenvolver um modelo híbrido neuronal para o processo de fermentação alcoólica usando balanços de massa combinados com redes neuronais do tipo Functional Link. Será implementado um esquema para atualização dos pesos da rede sempre que esta não descrever o comportamento dinâmico da planta. O modelo desenvolvido será usado para descrever um processo real no lugar dos modelos fenomenológicos existentes, já que estes têm sido capazes de descrever o processo apenas por curtos espaços de tempo<br>Abstract: The use of ethanol as a fuel has many advantages; it has economically competed with gasoline and others fuels, substituting them in various uses. Thus, there is a great interest in optimizing all the steps of ethanol production. Only a detailed knowledge of the process dynamics can lead to optimal operation and this can be achieved through simulation using an accurate model. Many phenomenological models were developed considering industrial fermentations, but they are only valid for specific conditions. Changes occur frequently in an industrial unity and frequent reestimation of model parameters is usually expensive and time consuming. The objective of this work is to develop a hybrid neural model for the alcoholic fermentation process using mass balances combined with Functional Link Neural Networks. A scheme to update network weights always that it does not describe plant behavior accurately is implemented. The developed model is used to describe an industrial process substituting the existing phenomenological models, since they have been able to describe the process only for short periods<br>Mestrado<br>Desenvolvimento de Processos Biotecnologicos<br>Mestre em Engenharia Química

Submitted by MILENA HELOISA POZENATTO BICUDO TOGNETE null (mibicudo28@gmail.com) on 2017-03-28T20:38:07Z No. of bitstreams: 1 Dissertacao versao final.pdf: 1702848 bytes, checksum: c8c7d8d8e47d1bf45f97875ac83a2798 (MD5)<br>Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-30T17:07:32Z (GMT) No. of bitstreams: 1 tognete_mhpb_me_sjrp.pdf: 1702848 bytes, checksum: c8c7d8d8e47d1bf45f97875ac83a2798 (MD5)<br>Made available in DSpace on 2017-03-30T17:07:32Z (GMT). No. of bitstreams: 1 tognete_mhpb_me_sjrp.pdf: 1702848 bytes, checksum: c8c7d8d8e47d1bf45f97875ac83a2798 (MD5) Previous issue date: 2017-02-17<br>Este estudo tem como objetivo avaliar a matéria-prima e sua influência isolada no desempenho do rendimento fermentativo de uma linhagem padrão da levedura CAT-1 testada em 31 meios de cultivos provenientes do processo de fermentação alcoólica da Usina Virgolino de Oliveira – Unidade Catanduva. Os meios foram amostrados e compostos a cada quinzena durante toda as safras 2012 e 2013. O trabalho também tem como finalidade identificar a dinâmica populacional das leveduras do mesmo processo fermentativo, através da diferenciação das linhagens por cariotipagem. As cepas isoladas foram testadas em um meio de cultivo padrão para obtenção das características tecnológicas industriais através da metodologia da Capacidade Fermentativa. Os experimentos de fermentação foram realizados nos laboratórios da Usina Virgolino de Oliveira - Unidade Catanduva em escala reduzida sempre acompanhados de um ensaio padrão utilizando meio de cultivo sintético. O primeiro ponto de estudo consistiu na caracterização da matéria-prima, mosto, e sua capacidade isolada de perturbar o Rendimento Fermentativo. Enquanto que no segundo, onde onze diferentes cepas de levedura foram identificadas ao longo das duas safras, testadas em um mesmo meio de cultivo padrão para obtenção de parâmetros industriais tecnológicos como rendimento em produto (Yp/s), rendimento em célula (Yx/s), Velocidade de consumo do substrato (Vcs), Produtividade (PROD) e Conversão (CONV) e estudada a influência no Rendimento Fermentativo. O terceiro ponto de estudo foi a comparação entre os rendimentos fermentativos obtidos experimentalmente e os rendimentos fermentativos industriais da Planta. O impacto da presença das cepas com maior rendimento em etanol foi estudado em relação aos valores de rendimento fermentativo industrial. Os resultados mostraram diferenças de desempenho da Cepa Padrão na maioria das quinzenas testadas, o que significa que há variação da matéria-prima ao longo da safra e entre as safras capazes de afetar rendimento fermentativo. Diferenças de rendimento também foram observadas entre as onze cepas nativas testadas, porém com oscilações menores e menos consideráveis do que com a matéria-prima. Os resultados obtidos em escala reduzida com base nos balanços de massa se apresentaram valores semelhantes em relação aos números de referência o que sugere que a metodologia usada para avaliar a capacidade fermentativa das cepas e a qualidade da matéria-prima foi adequada. Apesar da forte influência dos fatores estudados, não foi possível afirmar, através destes experimentos, qual deles teve papel determinante no impacto do Rendimento Fermentativo. Isso sugere que outros fatores não estudados neste trabalho estão diretamente relacionados que são capazes de influenciar o Rendimento Fermentativo.<br>The purpose of this study is to evaluate the sucrose mash and its influence isolated on the performance of the Fermentative Yeld of a standard strain from CAT-1 yeast tested in 31 different culture medium formulation from the Virgolino de Oliveira Plant – Catanduva Unit alcoholic fermentation process. The culture medium formulation were sampled and composed every fortnight during the whole 2012 and 2013 harvest. The work also has as purpose to evaluate the yeasts population dynamics of the same fermentative process, through the differentiation of the strains by karyotyping. The isolated strains were tested in a standard culture medium to obtain the industrial technological characteristics through the Fermentative Capacity methodology. Fermentation experiments were carried out in mill’s laboratories on a reduced scale always accompanied by a standard assay using synthetic culture medium formulation. The first point of study consisted in the characterization of the raw material, sucrose mash, and its isolated capacity to disturb Fermentative Yield. In the second, eleven different strains of yeast identified during the two harvests, they were tested in the same culture medium to obtain industrial technological parameters as Yield in product (Yp/s), Yield in cell (Yx/s), Substrate consumption velocity (Vcs), Productivity (PROD) and Conversion (CONV) and studied their influence on the Fermentative Yield. The third point of study was the comparison between the fermentative yields obtained experimentally and the industrial fermentative yields of the Plant. The impact of the presence of strains with higher Yp/s was studied in relation to industrial fermentation yield values. The results showed differences in performance of the Standard Strain in most of the fortnight tested, which means that there is variation of the raw material during the harvest and between the crops capable of affecting fermentative yield. There were also Yeld difference observed among the eleven native strains tested, but with smaller and less considerable oscillations than with the raw material. The results obtained on a reduced scale based on the mass balances were within the range expected in relation to the reference values, which suggests that the methodology used to evaluate the fermentative capacity of the strains and the quality of the raw material was adequate. Despite the strong influence of the studied factors, it was not possible to prove, through these experiments, which one had a determinant role in the Fermentative Yield impact. This suggests that other factors not studied in this work are directly related that are able to influence Fermentative Yield.

Orientador: Márcia Justino Rossini Mutton<br>Banca: Marco Antonio de Castro e Souza<br>Banca: Clóvis Parazzi<br>Resumo: A cana-de-açúcar e uma cultura importante para a economia do país, devido à sua alta eficiência na produção e acúmulo de sacarose. Entretanto, com a utilização crescente de cana crua tem se observado aumento de impurezas vegetais nos carregamentos, tais como folhas e pontas, ricas em amido, que interferem negativamente na produção de açúcar e álcool. Este trabalho teve por objetivo avaliar o desempenho de leveduras com atividade amilolítica na produção do álcool. Os testes foram feitos com três linhagens de leveduras amilolíticas, J07, J32 e Saccharomyces diastaticus, em combinação com uma levedura alcoogênica (Saccharomyces cerevisiae - CAT-01) em mosto preparado de caldo de cana da variedade SP81-3250, que apresentava elevado teor de amido. No vinho foram realizadas análises de açúcares redutores totais, teor alcoólico, glicerol, acidez sulfúrica e viabilidade celular. Os resultados revelaram que a combinação da CAT-01 com a linhagem J07 incrementou a produção de álcool. A levedura selvagem J32 não se constituiu boa fermentadora, podendo ser utilizada em combinação com outras linhagens de leveduras fermentadoras.<br>Abstract: Sugarcane is a very important crop to the economy of Brazil, because of its high efficiency in producing and accumulating sucrose. However, the rising rate of green cane harvest has resulted in higher levels of plant impurities as leaves and tops, which are rich in starch and affect both sugar and ethanol production. This work was carried out to evaluate the performance of amylolytic yeasts for ethanol production. The amylolytic strains J07 and J32, both isolated from the fermentation process, and Saccharomyces diastaticus were used in combination with Saccharomyces cerevisiae in a high-starch must from the sugarcane variety SP81-3250. The levels of total reducing sugars, ethanol, glycerol, sulfuric acidity and cell viability were determined. Results showed that the combination of S. cerevisiae with J07 increases ethanol production. The native yeast J32 has shown to be not good for fermentation, and for this reason must be used in combination with high fermentation yield strains.<br>Mestre

Made available in DSpace on 2014-06-11T19:27:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-12Bitstream added on 2014-06-13T19:55:58Z : No. of bitstreams: 1 puglia_al_me_jabo.pdf: 623951 bytes, checksum: 412280585efd51778c86c7f2dffec757 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>A cana-de-açúcar e uma cultura importante para a economia do país, devido à sua alta eficiência na produção e acúmulo de sacarose. Entretanto, com a utilização crescente de cana crua tem se observado aumento de impurezas vegetais nos carregamentos, tais como folhas e pontas, ricas em amido, que interferem negativamente na produção de açúcar e álcool. Este trabalho teve por objetivo avaliar o desempenho de leveduras com atividade amilolítica na produção do álcool. Os testes foram feitos com três linhagens de leveduras amilolíticas, J07, J32 e Saccharomyces diastaticus, em combinação com uma levedura alcoogênica (Saccharomyces cerevisiae - CAT-01) em mosto preparado de caldo de cana da variedade SP81-3250, que apresentava elevado teor de amido. No vinho foram realizadas análises de açúcares redutores totais, teor alcoólico, glicerol, acidez sulfúrica e viabilidade celular. Os resultados revelaram que a combinação da CAT-01 com a linhagem J07 incrementou a produção de álcool. A levedura selvagem J32 não se constituiu boa fermentadora, podendo ser utilizada em combinação com outras linhagens de leveduras fermentadoras.<br>Sugarcane is a very important crop to the economy of Brazil, because of its high efficiency in producing and accumulating sucrose. However, the rising rate of green cane harvest has resulted in higher levels of plant impurities as leaves and tops, which are rich in starch and affect both sugar and ethanol production. This work was carried out to evaluate the performance of amylolytic yeasts for ethanol production. The amylolytic strains J07 and J32, both isolated from the fermentation process, and Saccharomyces diastaticus were used in combination with Saccharomyces cerevisiae in a high-starch must from the sugarcane variety SP81-3250. The levels of total reducing sugars, ethanol, glycerol, sulfuric acidity and cell viability were determined. Results showed that the combination of S. cerevisiae with J07 increases ethanol production. The native yeast J32 has shown to be not good for fermentation, and for this reason must be used in combination with high fermentation yield strains.

Orientador: Gustavo Paim Valença<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química<br>Made available in DSpace on 2018-08-19T09:11:35Z (GMT). No. of bitstreams: 1 Duarte_JulianaCanto_M.pdf: 3529102 bytes, checksum: 186eed7fa5f67708a7cffe441cb0563a (MD5) Previous issue date: 2011<br>Resumo: A utilização de sistemas empregando células de levedura imobilizadas é uma técnica promissora para a produção de etanol. Este trabalho apresenta a proposta de imobilizar células de Saccharomyces cerevisiae em montmorilonita K10, em óxido de zircônio, em esferas de alginato de cálcio e em esferas de alginato de cálcio revestidas com quitosana, utilizando glicose e sacarose como fontes de carbono, a fim de observar o comportamento destas células nestes suportes. Estudos nesta área têm demonstrado que células imobilizadas apresentam maior resistência a variações de temperatura, atividade, concentração de substratos e metabólitos, além de um alto rendimento para fermentação alcoólica. A montmorilonita K10, o alginato de sódio e a quitosana que foram utilizados nos estudos tiveram origem comercial, enquanto que o óxido de zircônio foi sintetizado e caracterizado através de Difração de Raios-X (DRX) e área superficial B.E.T. (Brunauer, Emmet e Teller). Células de Saccharomyces cerevisiae liofilizada não aderiram aos suportes sólidos (montmorilonita K10, óxido de zircônio e óxido de zircônio com superfície modificada). Já a cepa JAY 270 de Saccharomyces cerevisiae foi imobilizada com sucesso em esferas de alginato de cálcio e em esferas de alginato de cálcio revestidas com quitosana. Estudos de fermentação em regime batelada foram conduzidos em shaker orbital para avaliação da produção de etanol, estabilidade, rendimento, taxa de consumo de substratos e taxa de produção de produto. O comportamento destes sistemas foi avaliado através de dados de concentração de substrato e produto em equipamento de HPLC (High-Performance Liquid Chromatograph). A imobilização celular em esferas de alginato de cálcio e em esferas de alginato de cálcio revestidas com quitosana permitiu a reutilização das esferas durante oito ciclos de fermentação de aproximadamente 10 horas cada. A produção de etanol para células livres foi 40 g/L e o rendimento foi de 78% e 74,3% utilizando a glicose e a sacarose como fontes de carbono, respectivamente. Para as células imobilizadas em esferas de alginato de cálcio, utilizando a glicose como fonte de carbono, a produção de etanol foi de 33 g/L e o rendimento foi de 64,6 %, utilizando a sacarose, a produção de etanol foi de 33 g/L e o rendimento foi de 61,3%. Para as células imobilizadas em esferas de alginato de cálcio revestidas com quitosana, utilizando a glicose como fonte de carbono, a produção de etanol foi de 31 g/L e o rendimento foi de 60,7 % e utilizando a sacarose, a produção de etanol foi de 32 g/L e o rendimento foi de 59,5%<br>Abstract: The use of immobilized yeast cells in supports systems is a promising technique for the ethanol production. This work proposes to immobilize Saccharomyces cerevisiae cells in montmorillonite K10, zirconium oxide, calcium alginate beads and chitosan covered calcium alginate beads, using glucose and sucrose as carbon sources, in order to observe the behavior of these cells in these media. Studies in this area have demonstrated that immobilized cells are more resistant to temperature, activity, concentration of substrates and metabolites, and a high yield for ethanol fermentation. The montmorillonite K10, sodium alginate and chitosan have been used in the studies had commercial origin, while the zirconium oxide was synthesized and characterized by X-ray Diffraction (XRD) and B.E.T. surface area (Brunauer, Emmet and Teller). Liofilized Saccharomyces cerevisiae did not adhere to solid supports (K10 montmorillonite, zirconium oxide and modified surface zirconium oxide). Since the strain of Saccharomyces cerevisiae, JAY 270, was successfully immobilized in calcium alginate beads and in chitosan covered calcium alginate beads. Studies under batch fermentation were conducted in orbital shaker for evaluation of ethanol production, stability, efficiency, substrate consumption rate and the product production rate. The behavior of these systems was assessed using concentration data of substrate and product in the HPLC equipment (High-performance liquid chromatography). The cell immobilization in calcium alginate beads and chitosan covered calcium alginate beads allowed reusing of the beads during fermentation of eight cycles every 10 hours. The production of ethanol to free cells was 40 g/L and 78% and 74.3% yield using the glucose and sucrose as carbon sources, respectively. For immobilized cells in calcium alginate beads, ethanol production was 33 g/L and 64.6% yield and 33 g/L and 61.3% yield, using glucose and sucrose, respectively. For immobilized cells in chitosan covered calcium alginate beads, ethanol production was 31 g/L and 60.7% yield and 32 g/L and 59.5% yield, using glucose and sucrose, respectively<br>Mestrado<br>Desenvolvimento de Processos Químicos<br>Mestre em Engenharia Química

Made available in DSpace on 2014-06-11T19:32:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-31Bitstream added on 2014-06-13T19:42:39Z : No. of bitstreams: 1 antonangelo_atbf_dr_botib.pdf: 1383699 bytes, checksum: 62761d8607d84c569f6220176bc59b97 (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>O Brasil é atualmente o maior produtor mundial de álcool de cana de açúcar, sendo responsável por uma produção anual de aproximadamente 27 bilhões de litros. O álcool é produzido através da fermentação do caldo de cana-de-açúcar e/ou melaço por células de levedura da espécie Saccharomyces cerevisiae. Embora, atualmente, muitas indústrias utilizem cepas selecionadas de S. cerevisiae como iniciadoras, a condição não estéril dos substratos torna este processo sujeito a constantes contaminações por bactérias e linhagens de leveduras nativas de Saccharomyces cerevisiae e não-Saccharomyces cerevisiae. Estas leveduras nativas dominam rapidamente a população iniciadora do processo por serem cepas genética e fisiologicamente adaptadas às condições daquele ambiente. Tais leveduras podem prejudicar o processo fermentativo, porém, algumas entre elas, podem apresentar características positivas. Atualmente no Brasil várias indústrias acompanham a dinâmica populacional da fermentação por cariotipagem. No entanto este método é dispendioso, demorado e pouco acurado quando se compara a outros métodos moleculares mais sensíveis. Este trabalho se propõe a utilizar a técnica de PCR microssatélite para diferenciar linhagens de leveduras presentes no processo de fermentação em usinas de álcool, acompanhar a dinâmica populacional de uma usina durante uma safra e estudar a diversidade genética e a estrutura populacional das cepas nativas presentes no processo industrial de produção do álcool combustível. O trabalho também visa investigar a presença de single nucleotide polymorphism (SNP) ou mutações de base única nas cepas nativas de Saccharomyces cerevisiae isoladas deste processo e relacioná-los à capacidade de floculação e à tolerância ao ambiente industrial estressante. Durante o trabalho...<br>Brazil is the major world producer of ethanol from sugar cane, producing about 27 billion liters of ethanol a year. Alcohol is the result of sugar cane juice/ molasses fermentation by Saccharomyces cerevisiae yeast cells. Although many sugar mills in Brazil currently start the fermentation process by inoculating selected Saccharomyces cerevisiae commercial strains, it often occurs the incoming of bacteria, native Saccharomyces and non-Saccharomyces yeast strains because of its unsterile condition. In this process these indigenous strains outnumber the population inoculated and those which are genetically and physiologically better adapted tend to dominate. These strains may either show desirable fermentative qualities or not. The method currently used in Brazil to investigate sugar cane must population is electrophoresis karyotyping, however this method is expensive, time consuming and not very accurate when compared with other more sensitive molecular methods. This work aimed at using microsatellite PCR method for differentiating yeasts strains from alcohol plants fermentation process, monitoring population dynamic of a bioethanol fuel plant during a harvest season and studying the genetic diversity and population structure of native strains from bioethanol production industrial process. This work also aimed at investigating SNPs occurrence among Saccharomyces cerevisiae native strains that could be related with flocculation and stressful industrial environment tolerance. Twenty- four microsatellite loci were tested and 12 of them were polymorphic and capable of differentiating the commercial selected strains BG-1, CAT-1, PE-2 e SA-1 from each other and also capable of screening indigenous strains from the inoculated ones. Four loci were used for monitoring Usina São Manoel harvest season during 2008 where were observed... (Complete abstract click electronic access below)

Orientador: Débora Colombi<br>Coorientador: Paulo Eduardo Martins Ribolla<br>Banca: Maria da Graça Stupiello Andrieta<br>Banca: Sandra Regina Ceccato Antonini<br>Banca: Celso Marino<br>Banca: Eduardo Bagagli<br>Resumo: O Brasil é atualmente o maior produtor mundial de álcool de cana de açúcar, sendo responsável por uma produção anual de aproximadamente 27 bilhões de litros. O álcool é produzido através da fermentação do caldo de cana-de-açúcar e/ou melaço por células de levedura da espécie Saccharomyces cerevisiae. Embora, atualmente, muitas indústrias utilizem cepas selecionadas de S. cerevisiae como iniciadoras, a condição não estéril dos substratos torna este processo sujeito a constantes contaminações por bactérias e linhagens de leveduras nativas de Saccharomyces cerevisiae e não-Saccharomyces cerevisiae. Estas leveduras nativas dominam rapidamente a população iniciadora do processo por serem cepas genética e fisiologicamente adaptadas às condições daquele ambiente. Tais leveduras podem prejudicar o processo fermentativo, porém, algumas entre elas, podem apresentar características positivas. Atualmente no Brasil várias indústrias acompanham a dinâmica populacional da fermentação por cariotipagem. No entanto este método é dispendioso, demorado e pouco acurado quando se compara a outros métodos moleculares mais sensíveis. Este trabalho se propõe a utilizar a técnica de PCR microssatélite para diferenciar linhagens de leveduras presentes no processo de fermentação em usinas de álcool, acompanhar a dinâmica populacional de uma usina durante uma safra e estudar a diversidade genética e a estrutura populacional das cepas nativas presentes no processo industrial de produção do álcool combustível. O trabalho também visa investigar a presença de single nucleotide polymorphism (SNP) ou mutações de base única nas cepas nativas de Saccharomyces cerevisiae isoladas deste processo e relacioná-los à capacidade de floculação e à tolerância ao ambiente industrial estressante. Durante o trabalho... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Brazil is the major world producer of ethanol from sugar cane, producing about 27 billion liters of ethanol a year. Alcohol is the result of sugar cane juice/ molasses fermentation by Saccharomyces cerevisiae yeast cells. Although many sugar mills in Brazil currently start the fermentation process by inoculating selected Saccharomyces cerevisiae commercial strains, it often occurs the incoming of bacteria, native Saccharomyces and non-Saccharomyces yeast strains because of its unsterile condition. In this process these indigenous strains outnumber the population inoculated and those which are genetically and physiologically better adapted tend to dominate. These strains may either show desirable fermentative qualities or not. The method currently used in Brazil to investigate sugar cane must population is electrophoresis karyotyping, however this method is expensive, time consuming and not very accurate when compared with other more sensitive molecular methods. This work aimed at using microsatellite PCR method for differentiating yeasts strains from alcohol plants fermentation process, monitoring population dynamic of a bioethanol fuel plant during a harvest season and studying the genetic diversity and population structure of native strains from bioethanol production industrial process. This work also aimed at investigating SNPs occurrence among Saccharomyces cerevisiae native strains that could be related with flocculation and stressful industrial environment tolerance. Twenty- four microsatellite loci were tested and 12 of them were polymorphic and capable of differentiating the commercial selected strains BG-1, CAT-1, PE-2 e SA-1 from each other and also capable of screening indigenous strains from the inoculated ones. Four loci were used for monitoring Usina São Manoel harvest season during 2008 where were observed... (Complete abstract click electronic access below)<br>Doutor

A monitoração do processo de fermentação alcoólica para a obtenção de etanol é um tema de grande interesse pelo fato deste ser utilizado como fonte sustentavel de energia na indústria. Os processo de monitoração convencionalmente utilizados na indústria são dispendiosos, baseados em medições supervisionadas de densidade e estimativas de parâmetros químicos mediante procedimentos offline. O uso de técnicas de monitoração não invasivas baseadas em ultra-som vem sendo desenvolvidas para esse fim, fazendo uso de estimativas de parâmetros clássicos como a velocidade de propagação acústica e a atenuação. No entanto, a evolução do processo fermentativo não é bem descrita por esses parâmetros. Devido a isso, o presente trabalho propõe um sistema híbrido de processamento de sinais de ultra-som que utiliza um conglomerado de parâmetros para uma caracterização mais eficiente do processo fermentativo. O sistema incorpora procedimentos computacionais para a detecção, caracterização e classificação das fases do mosto em fermentação, visto como uma suspensão sólido-líquido (fase dispersa e contínua). Esses procedimentos foram baseadas em estimativas de estacionariedade dos sinais de retroespalhamento de ultra-som ( teste de hipotese não paramétrico - Teste de Run), ajuste de curvas sobre a largura de banda espectral (técnica de curve fitting), assim como a extração de atributos espectrais tais como : frequência central, largura de banda e valores de amplitude da componente fundamental, entre outros, além de parâmetros ultra-sônicos como o coeficiente de atenuação (slope) e o coeficiente integrado de retro-espalhamento (IBC). Para a classificação foi utilizado o algoritmo K-means. Os resultados obtidos mostraram a viabilidade na caracterização multiparamétrica não invasiva do fluido em fermentação, permitindo a identificação das principais fases do processo fermentativo. O trabalho contribui com uma metodología alternativa para a avaliação da cinética do crescimento microbiano como indicador da evolução da fermentação alcoólica.<br>Monitoring of alcoholic fermentation process for the ethanol production is a topic of great interest because it can be used as a sustainable energy source in the industry. The monitoring process conventionally used in industry are expensive, based on supervised measurements of density and parameter estimates by chemical offline procedures. The use of noninvasive monitoring techniques based on ultrasound are being developed for this purpose, using estimates of classical parameters as the acoustic propagation velocity and attenuation. However, the time evolution of the fermentation process is not well described by these parameters. For this reason, this study proposes a hybrid system of ultrasound signal processing that uses a conglomerate of parameters aiming a more efficient characterization about the fermentation process. The system incorporates computational procedures for the detection, characterization and classification of the fermentation must phases, seen as a solid-liquid suspension (dispersed and continuous phases). These procedures were based on estimates of stationarity for ultrasound backscattered signals (non-parametric statistical test - Run Test), curve fitting on the spectral bandwidth, as well as spectral attributes extraction such as center frequency, bandwidth and energy values of the fundamental frequency and so on, plus ultrasonic parameters as the attenuation coefficient (slope) and the integrated back-scattering coefficient (IBC). For classification we used the k-means algorithm. The results showed the feasibility for the multiparametric noninvasive characterization of fluid in fermentation, identifying the main stages of the fermentation process. This work contributes with an alternative methodology to evaluate the kinetics of microbial growth as an indicator of the alcoholic fermentation evolution.