Thesis (M.S.)--Mississippi State University. Department of Chemistry. / Title from title screen. Includes bibliographical references.

Thesis (M.S.) -- Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--Ohio University, March, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (MScAgric)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The quality of wine is influenced by numerous factors. These factors include the quality of the grapes, winemaking techniques and quality control throughout the winemaking process. It is thus very important that any process leading to the lowering of the quality of the wine be prevented. Evidence in the wine industry shows that bacterial spoilage is still very much a common problem in many wineries. The spoilage of wine by bacteria can lead to amongst other problems, elevated volatile acidity levels, of which only a certain concentration limit in wine is permitted. Usually more than 90% of the volatile acidity of wine consists of acetic acid. Different yeast strains, heterofermentative lactic acid bacteria and acetic acid bacteria (which can all be spoilage microorganisms) can produce acetic acid in high concentrations. It is thus important to be able to prevent the formation of this acid by controling the unwanted growth of these spoilage microorganisms. Acetic acid and other medium chain fatty acids, octanoic- and decanoic acid, can also lead to stuck or sluggish fermentations. A stuck or sluggish fermentation can also lead to wine spoilage, due to sugar remaining in the fermentation which can be utilized by spoilage microorganisms. Acetic- and other fatty acids enter the yeast cell by passive diffussion and releases its proton in the cytoplasm, thereby acidifying the cytoplasm and inhibiting some enzymes. These acids can also work synergistically with ethanol and its inhibitory effect is also dependent on the temperature. Yeast strains can also differ in their resistance to acetic and other medium chain fatty acids and these acids can also influence the growth of lactic acid bacteria. How acetic acid bacteria influence the winemaking process and the used measures to keep these bacteria from spoiling wine have been the subject of very little attention in the past. This was due to the belief that the anaerobic conditions prevailing in wine and the use of sulfur dioxide are enough to control these bacteria, since acetic acid bacteria were always described as being strictly aerobic microorganisms. Recently, some evidence showed that acetic acid bacteria can survive and even overcome the limits that the winemaking process places on its growth. These bacteria are also known to inhibit the yeasts growth and fermentation ability due to the production of acetic acid and other factors. A research programme on the origin of volatile acidity in South African wines had been initiated at the Department of Viticulture and Enology and at the Institute for Wine Biotechnology at the University of Stellenbosch after increases in volatile acidity in different South African wines had been reported. This spurred us to investigate the occurrence of acetic acid bacteria in South African red wine fermentations, which forms part of this study, and to identify the dominant acetic acid bacterial strains. The sulfur dioxide resistance of five representative strains were also determined, as well as the effect of metabolites which were produced by these bacteria on yeast growth and fermentation ability. Our results indicate that acetic acid bacteria can occur in high concentrations in the fresh must and during alcoholic fermentation. In the 1998 harvesting season acetic acid bacteria occurred at 106-107 cfu per ml in the fresh must. In 1999 these numbers were 104-105 cfu/ml. Acetic acid bacteria numbers decreased in 1998 to 102-103 cfulml during fermentation. The survival of these bacteria in 1999 correlated with the pH of the must, as well as sulfur dioxide dosages in the must. In must with a low pH and higher sulfur dioxide the number of acetic acid bacterial numbers decreased more drastically than in the high pH, low sulfur dioxide musts. This was also true for acetic acid bacterial counts during cold soaking of musts, with the number of acetic acid bacteria increasing during the cold soaking period in musts with a high pH. In musts with a low pH and higher S02 dosages acetic acid bacterial counts did not, however, increase during cold soaking. Gluconobacter oxydans dominated in the fresh must with Acetobacter liquefaciens and especially Acetobacter pasteurianus dominating during the fermentation. Different biochemical and physiological tests revealed that 52% of the 115 isolates tested belong to A. pasteurianus. The high occurrence of A. liquefaciens with A. pasteurianus during fermentation showed that the dominant acetic acid bacterial species in South Africa differed from reports from other wine producing countries. The sulfur dioxide resistance of the acetic acid bacteria tested also differed in white grape juice, with a molecular sulfur dioxide concentration of 0.64 mg/I being necessary to eliminate all the acetic acid bacterial strains tested. The A. hansenii strain was found to be the most resistant to sulfur dioxide and G. oxydans the least resistant. The latter strain was eliminated by only 0.05 mg/I molecular sulfur dioxide, while A. hansenii was only eliminated by 0.64 mg/I molecular sulfur dioxide. The A. pasteurianus, A. liquefaciens and A. aceti strains tested displayed varying degrees of resistance to sulfur dioxide. The volatile acidity produced by these bacteria profoundly influenced the growth and fermentation ability of yeast, which led to slow/stuck fermentation. The A. hansenii and A. pasteurianus strains produced the most volatile acidity in grape juice, with up to 4.02 g/I for A. hansenii within 4 days, which led to a stuck alcoholic fermentation. This was, however, prevented by inhibiting or eliminating the acetic acid bacteria with sufficient sulfur dioxide additions prior to yeast inoculation. Compounds produced by acetic acid bacteria can also influence wine quality. Certain organic acids were produced and metabolized by acetic acid bacteria, as well as acetoin. We could not, however, detect any other fatty acids that are inhibitory to yeast (produced by these bacteria). This study clearly showed that acetic acid bacteria could occur during fermentation and that certain winemaking techniques, like the maintenance of a low pH in the must and sulfur dioxide additions can influence the growth and survival of acetic acid bacteria. Acetic acid bacteria also influence both the winemaking process by inhibiting yeast as well as the quality of the wine by producing acetic acid and/or other compounds. This study also shed some light on the occurrence of acetic acid bacterial species in the South African context and could be important in assisting the winemaker, as well as the scientific reseacher, in finding ways to inhibit acetic acid bacteria in the ongoing battle against these spoilage microorganisms of wine. / AFRIKAANSE OPSOMMING: Wynkwaliteit word deur verskillende faktore beinvloed. Dit sluit die druifkwaliteit, wynmaak tegnieke en kwaliteitsbeheer deur die wynmaakproses in. Enige prosesse en faktore wat tot die verlaging in wynkwaliteit kan lei moet dus ten alle koste voorkom word. Die bederf van wyn deur bakterieë kan en is 'n algemene probleem in enige kelder. Bakteriese bederf kan, onder andere, lei tot verhoogte vlugtige suurheid, waarvan 'n sekere konsentrasie limiet in wyn toegelaat word. Asynsuur maak gewoonlik 90% van die vlugtige suurheid uit. Asynsuur kan deur verskillende gisrasse, heterofermantatiewe melksuurbakterieë en asynsuurbakterieë (wat almal wyn kan bederf) gevorm word. Die vorming van asynsuur in wyn kan dus voorkom word deur die ongewenste groei van dié organismes te voorkom. Asynsuur en ander medium ketting vetsure, soos oktanoë- en dekanoësuur, kan ook tot slepende of gestaakte gistings lei. Suiker wat in die wyn agterbly wat In slepende/gestaakte fermentasie ondergaan kan deur bederf bakterieë gebruik word om die wyn te bederf. Ongedissosieerde asynsuur en ander vetsure dring die gissel binne deur passiewe diffussie en stel 'n proton vry in die sitoplasma wat sitoplasma versuur en sekere ensieme inhibeer. Hierdie sure werk ook sinergisties met etanol en hul inhiberede effek is ook temperatuur afhanklik. Gisrasse verskil in hul weerstandbiedendheid teen asynsuur- en ander mediumketting vetsure en dié vetsure kan ook melksuurbakterieë se groei beïnvloed. Hoe asynsuurbakterieë wyn bederf en die aksies wat geneem kan word om dit te verhoed is in die verlede nie baie ondrsoek nie. Dit is hoofsaaklik daaraan toe te skryf dat geglo is dat die anaerobiese kondisies in wyn en die gebruik van swaweidioksied die groei van asynsuurbakterieë, wat altyd beskryf is as streng aerobe mikroorganismes, kan beheer. Daar is onlangs aangetoon dat asynsuurbakterieë kan oorleef in wyn en selfs die ongunstige kondisies daarin kan oorkom. Hierdie bakterieë is ook in staat om gisgroei en fermentasie vermoë te inhibeer deur die produksie van asynsuur en ander faktore. In Navorsingsprogram om die oorsprong van verhoogde vlugtige suurheid in Suid-Afrikaanse wyne te bepaal is deur die Departement Wingerd- en Wynkunde en die Instituut vir Wynbiotegnologie van die Universiteit van Stellenbosch geinisieer. Dit het ons aangemoedig om die voorkoms van asynsuurbakterieë in Suid-Afrikaanse rooiwyngistings, wat deel vorm van hierdie ondersoek, en ook die dominante asynsuurbakterie rasse te identifiseer. Die swaweidioksied bestandheid van vyf verteenwoordegende rasse en die effek wat metaboliete wat deur dié bakterieë geproduseer is op gisgroei en gisitingsvermoë is bepaal. Ons resultate bewys dat asynsuurbakterieë teen hoë getalle in vars mos en gedurende alkoholiese gisting kan voorkom. Asynsuurbakterieë het gedurende die 1998 seisoen teen 106-107 kve/ml en in 1999 teen 104-105 kve/ml in die vars mos voorgekom. Gedurende fermentasie het hierdie getalle in die 1998 seisoen gedaal na 102-103 kve/ml. Die oorlewing van hierdie bakterieë het gedurende die 1999 seisoen gekorrelleer met die pH en swaweidioksied konsentrasies van die mos. In die lae pH, hoë swaweidioksied moste het asynsuurbakterie getalle vinniger en meer dramaties gedaal as in die hoë pH, lae swaweidioksied moste. Asynsuurbakterie getalle het dieselfde tendens getoon in moste gedurende dopkontak by lae temperature. In moste met 'n hoë pH het asynsuurbakterie getalle toegeneem gedurende koue dopkontak, terwyl dit nie gebeur het nie in moste met 'n lae pH en hoë swaweidioksied konsentrasies. In die vars mos het Gluconobacter oxydans en gedurende die fermentasie Acetobacter liquefaciens en veral Acetobacter pasteurianus oorheers. Verskillende biochemiese en fisiologiese toetse het bepaal dat 52% van die 115 isolate A. pasteurianus is. Die hoë voorkoms van A. liquefaciens saam met A. pasteurianus gedurende gisting bewys dat die voorkoms en dominansie van asynsuurbakterieë in Suid- Afrika verskil van ander wynproduserende lande. Die swaweidioksied weerstandbiedendheid van die asynsuurbakterieë wat getoets het, het ook verskil, met 0.64 mg/I molekulêre swaweIdioksied nodig om hul almal te elimineer in wit druiwesap. Die A. hansenii en G. oxydans rasse was die mees weerstandbiedend en sensitiefste onderskeidelik ten opsigte van swaweidioksied. Slegs 0.05 mg/I molekulêre swaweidioksied was voldoende om G. oxydans te elimineer, terwyl A. hansenii deur 0.64 mg/I molekulêre swaweidioksied geëlimineer is. Die A. pasteurianus, A. liquefaciens en A. aceti rasse het verskillende swaweidioksied weerstandbiedendheid getoon. Die vlugtige suurheid wat deur dié bakterieë geproduseer is het die groei en gistingvermoë van gis drasties beinvloed, wat tot slepende/gestaakte fermentasies gelei het. Die A. hansenii en A. pasteurianus rasse het die meeste vlugtige suurheid geproduseer, met tot 4.02 g/I geproduseer deur A. hansenii na vier dae se groei, wat tot 'n gestaakte fermentasie gelei het. Dit is egter voorkom deur die asynsuurbakterieë te elimineer deur genoegsame swaweidioksied toevoegings tot die mos voor gisinokulasie te doen. Verbindings wat deur asynsuurbakterieë geproduseer word kan ook wynkwaliteit beinvloed. Sekere anorganiese sure is deur hierdie bakterieë geproduseer, terwyl ander gemetaboliseer is. Asetoïen is geproduseer deur die getoetse asynsuurbakterieë. Ons kon egter nie ander vetsure wat gis inhibeer opspoor nie. (Geproduseer deur die bakterieë). Hierdie studie bewys dat asynsuurbakterieë gedurende alkoholiese fermentasie kan voorkom en dat sekere wynmaaktegnieke, soos die verkryging van moste met 'n lae pH en genoegsame swaweidioksied toevoegings die groei en oorlewing van asynsuurbakterieë kan beivloed. Asynsuurbakterieë kan ook beide die wynmaakproses, deur giste te inhibeer, en die wynkwaliteit beivloed deur die produksie van asynsuur en/of ander verbindings. Hierdie studie het ook kennis oor die voorkoms van asynsuurbakterieë in Suid-Afrikaanse moste verbeter en kan ook as 'n nuttige hulpmiddel dien vir die wynmaker en navorser in die stryd om hierdie bederf organismes van wyn te elimineer.

Made available in DSpace on 2014-06-11T19:32:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-06Bitstream added on 2014-06-13T21:05:11Z : No. of bitstreams: 1 pedrinho_ean_dr_jabo.pdf: 618876 bytes, checksum: 1ad857ab1fbea921a5b1a0748c8aaa28 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Estudos sobre a atividade microbiológica que ocorre na rizosfera de diversos vegetais levaram ao descobrimento de grupos de microrganismos importantes para o desenvolvimento vegetal. Dentre eles estão as rizobactérias que são capazes de colonizar as raízes, estimulando-a diretamente ou beneficiando o crescimento e o desenvolvimento de diversas plantas, essas bactérias são chamadas Rizobactérias Promotoras de Crescimento em Plantas ou RPCP. Este trabalho teve o objetivo de isolar, identificar, testar a capacidade da solubilização de fosfato, produção de ácido indol- acético (AIA) e fixação de nitrogênio de alguns isolados obtidos de quatro regiões diferentes do Brasil, assim como o efeito da inoculação destes em sementes de milho (híbrido Imapcto) testados na casa de vegetação. As metodologias utilizadas neste trabalho propiciaram a seleção de isolados que se destacaram positivamente. A análise parcial do gene 16S rRNA dos 87 isolados possibilitou a identificação dos gêneros, Bacillus, Burkholderia e Azospirillum, sendo os mais freqüentes totalizando 78% dos isolados, seguidos de Sphingomonas, Pseudomonas, Herbaspirillum, Pantoea e Bosea. Desses, 42 foram positivos no teste colorimétrico para detecção de produção do AIA e somente 24 apresentaram a capacidade de solubilização do fosfato. A partir destes resultados selecionou-se um organismo pertencente ao gênero Sphingomonas para ser testado em casa de vegetação como promotor de crescimento em conjunto com as estirpes de Azospirillum brasilense (AbV5 e AbV6). As plantas foram avaliadas quanto à altura, aos vinte e setenta dias após a germinação, e a massa seca da parte aérea e radicular foram quantificadas após setenta dias, no encerramento do experimento. Já a capacidade de redução do acetileno a etileno in vitro foi positiva somente para quatro organismos pertencentes aos gêneros Pseudomonas... / Studies on the microbial activity that occurs in the rhizosphere of different plants have led to the discovery of groups of important microorganisms to plant development. Among them are the rhizobacteria that are able to colonize the roots, stimulating it directly or benefiting the growth and development of many plants, these bacteria are called Plant Growth Promotion Rhizobacteria in plants or RPCP. This study aimed to isolate, identify, test the ability of phosphate solubilization, production of indoleacetic acid (IAA) and nitrogen fixation of some isolates from four different regions of Brazil, as well as the effect of inoculation in these maize seeds (hybrid Imapcto) tested in the greenhouse. The methods used in this study enabled the selection of isolates that stood out positively. The analysis of partial 16S rRNA gene of the 87 isolates allowed the identification of genera, Bacillus, Azospirillum and Burkholderia, with the most frequent totaling 78% of isolates, followed by Sphingomonas, Pseudomonas, Herbaspirillum, Pantoea and Bosea. Of these, 42 were positive in the colorimetric test for detection of production of the EIA and only 24 had the capacity of phosphate solubilization. From these results picked up a body belonging to the genus Sphingomonas to be tested in the greenhouse as promoter of growth together with the strains of Azospirillum brasilense (AbV5 and AbV6). The plants were then evaluated for the twenty and seventy days after germination and dry weight of shoot and root were quantified after seventy days, at the end of the experiment. The capacity of reduction of acetylene to ethylene in vitro were positive for only four bodies belonging to the genera Pseudomonas, Burkholderia, Sphingomonas and Herbaspirillum amid NFb. With these isolates tested was the ability to fix nitrogen evaluating the development of maize seedlings in a greenhouse for thirty days... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:26:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-26Bitstream added on 2014-06-13T20:34:26Z : No. of bitstreams: 1 camili_ec_me_botfca.pdf: 1770083 bytes, checksum: f5ea3a6bbc481ab702d9339e5ee2ce93 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Perdas significativas ocorrem durante o armazenamento e a comercialização de uvas de mesa devido, principalmente, à ocorrência do mofo cinzento (Botrytis cinerea Pers.:Fr.) e, visando o controle de patógenos emprega-se, geralmente, o dióxido de enxofre (SO2). Diante da restrição crescente ao uso de produtos químicos em pós-colheita, tem ocorrido considerável interesse em métodos alternativos de controle. Este trabalho teve como principal objetivo avaliar os efeitos dos agentes bióticos (Lentinula edodes (Berk.) Pegler e Agaricus blazei (Murril) ss. Heinem) e abióticos (quitosana, ácido acético e irradiação UV-C), possíveis indutores de resistência, na proteção de uva Itália pós-colheita contra B. cinerea. In vivo, avaliou-se o efeito direto e indireto dos agentes de controle através do tratamento dos cachos de uva, antes e após a inoculação com o patógeno. Utilizaram-se extratos aquosos dos cogumelos A. blazei (linhagem ABL 29) e L. edodes (linhagem LED 17) nas concentrações de 0,0; 2,5; 5,0; 10,0; 20,0 ou 40,0 % (v/v); quitosana nas concentrações de 0,00; 0,25; 0,50; 1,00; 1,50 e 2,00 % (v/v); vapor de ácido acético a 0,0; 2,6; 5,2; 10,5 ou 21,0 mg.L-1 e; irradiação UV-C (254 nm) nas doses de 0,00; 0,84; 1,30; 2,40; 3,60; 4,80 e 7,50 kJ.m-2. Para inoculação, em cada cacho foram feridas 10 bagas, fazendo-se um furo por baga de 2 mm de profundidade, procedendo-se em seguida, a aspersão da suspensão de conídios ( 105 conídios.mL-1) de B. cinerea. Após os tratamentos, os cachos foram mantidos a 25 1 C / 80-90 % UR; quando avaliações de incidência e severidade foram realizadas diariamente, além de análises físicas e físico-químicas da uva. Avaliações in vitro do efeito dos agentes de controle sobre o patógeno também foram realizadas analisando-se o crescimento micelial e a germinação dos conídios de B. cinerea... / Significant losses of table grapes occur during storage and commercialization due mainly to the occurrence of gray mold (Botrytis cinerea Pers.:Fr.), and sulfur dioxide (SO2) is frequently used to control such pathogens. Due to increasing restrictions on the postharvest use of chemical products, considerable interest in alternative control measures has arisen. The main objective of this study was to evaluate the effects of biotic (Lentinula edodes (Berk.) Pegler and Agaricus blazei (Murril) ss. Heinem) and abiotic (chitosan, acetic acid and UV-C irradiation) agents as possible resistance inducers in 'Itália' grapes, aimed at post-harvest protection against B. cinerea. The direct and indirect effects of these control agents were evaluated in vivo by treating bunches of grapes before and after inoculation with the pathogen. Aqueous extracts of the mushrooms A. blazei (strain ABL 29) and L. edodes (strain LED 17) were used in the concentrations of 0.0; 2.5; 5.0; 10.0; 20.0 and 40.0 % (v/v); chitosan at 0.00; 0.25; 0.50; 1.00; 1.50 and 2.00 % (v/v); acetic acid vapor at 0.0; 2.6; 5.2; 10.5 and 21.0 mg.L-1 and UV-C (254 nm) irradiation at doses of 0.00; 0.84; 1.30; 2.40; 3.60; 4.80 and 7.50 kJ.m-2. For inoculation, 10 grapes in each bunch were injured by piercing the grape to a depth of 2 mm, followed by spraying with the inoculum of B. cinerea conidia ( 105 conidia.mL-1). After the treatments, the bunches were kept at 25 1 C / 80-90 % RH, carrying out daily evaluations of disease incidence and severity, as well as physical and physical-chemical analyses of the grapes. In vitro evaluations of the effect of the control agents were also carried out based upon mycelial growth and germination of B. cinerea conidia. The results showed that the extracts of A. blazei and L. edodes failed to control deterioration by B. cinerea in 'Itália' grapes when applied after inoculation. However, the A. blazei... (Complete abstract, click electronic access below)

O hidrogênio é considerado uma das principais alternativas aos combustíveis fósseis. Dentre os processos para sua produção, a reforma a vapor do bio-óleo é uma das mais promissoras. Sendo o ácido acético um dos componentes majoritários do bio-óleo, ele vem sendo usado como molécula modelo na reforma a vapor. Porém, problemas como baixo desempenho catalítico e formação de coque ainda precisam ser contornados. Nesse sentido, o suporte utilizado tem um papel importante. No entanto, ainda não foi esclarecido quais propriedades do suporte contribuem mais para a eficiência catalítica. Neste trabalho, a reforma a vapor do ácido acético foi avaliada sobre catalisadores de níquel. Foram utilizados catalisadores constituídos de Ni0 ancorado em suportes com diferentes propriedades (MgO, ZrO2, TiO2 e Al2O3). A área superficial do suporte e a forte interação Ni-suporte foram fundamentais para a dispersão metálica dos catalisadores. A dispersão metálica e capacidade do suporte ativar a molécula de H2O foram as propriedades que aparentemente mais influenciaram no desempenho catalítico. Para as reações realizadas a 500 °C, a conversão do ácido acético, seletividade para H2 e formação de coque foram basicamente influenciadas pela dispersão metálica. Nas reações realizadas a 600 °C, a formação de coque foi menor para os catalisadores com maior dispersão metálica. A conversão do ácido acético e seletividade para H2 a 600 °C foram influenciadas pela dispersão metálica dos catalisadores, mas aparentemente a capacidade do suporte ativar a molécula de H2O foi o que mais contribui. O catalisador 10Ni/Al2O3 apresentou a maior dispersão metálica e em reações a 500 °C isso levou a uma alta conversão e alta seletividade para H2 com baixa formação de coque. O catalisador 10Ni/MgO apresentou desempenho regular em ambas as temperaturas. Já o catalisador 10Ni/TiO2 teve o pior desempenho independente da temperatura, devido à baixa dispersão metálica. Apesar da alta formação de coque devido à dispersão metálica relativamente baixa, o catalisador 10Ni/ZrO2 exibiu alta conversão e foi o mais seletivo para H2 a 600 °C, provavelmente pela capacidade do ZrO2 ativar a molécula de H2O. / Hydrogen (H2) is considered one of major alternatives to fossil fuels. Among the processes for H2 production, steam reforming of bio-oil is one of the most promising. As acetic acid is present in large amounts in bio-oil, it is used as model molecule in steam reforming reactions. However, problems such as low catalytic performance and coke formation yet need to be solved. In this sense, supports used display important role. However, it is not clear what support characteristics contribute more to catalytic properties. Here, acetic acid steam reforming was carried out over Ni catalysts. It were used catalysts consisting by Ni0 anchored in supports with different properties (MgO, ZrO2, TiO2 and Al2O3). Surface area of support and strong Ni-support interaction were key to metal dispersion of catalysts. Metal dispersion and the capacity of support to activate H2O molecule were apparently the properties that more influence the catalytic performance. For reactions carried out at 500 °C acetic acid conversion, H2 selectivity and coke formation were primarily influenced by metal dispersion. In reactions performed at 600 °C coke formation was lower for catalysts with higher metal dispersion. Acetic acid conversion and H2 selectivity at 600 °C were influenced by metal dispersion of catalysts, but apparently the ability of support to activate H2O molecule was the most important. 10Ni/Al2O3 showed higher metal dispersion and at 500 °C this led to a high conversion and high selectivity for H2 with low coke formation. 10Ni/MgO catalyst showed intermediate performance at both temperatures. Already 10Ni/TiO2 catalyst had the worst performance independent of temperature due to low metal dispersion. Despite the high coke formation, due to the relatively low metal dispersion, 10Ni/ZrO2 catalyst exhibited high conversion and was the most selective to H2 at 600 °C, probably due to the ability of ZrO2 to activate H2O molecules.

Submitted by Elisa Fonseca Horta null (elisafhort@hotmail.com) on 2017-10-04T17:21:58Z No. of bitstreams: 1 Dissertação Elisa Fonseca Horta.pdf: 1842613 bytes, checksum: c58c4e6716def5976cd8668135065c87 (MD5) / Rejected by Monique Sasaki (sayumi_sasaki@hotmail.com), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: O arquivo submetido está sem a ficha catalográfica. O arquivo submetido não contém o certificado de aprovação. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija estas informações e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2017-10-04T17:54:31Z (GMT) / Submitted by Elisa Fonseca Horta null (elisafhort@hotmail.com) on 2017-10-09T17:21:18Z No. of bitstreams: 1 Dissertação Elisa Fonseca Horta.pdf: 1848190 bytes, checksum: a5ac9a5af484d749ce6cad8c93ccd0be (MD5) / Rejected by Luiz Galeffi (luizgaleffi@gmail.com), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A versão final da dissertação/tese deve ser submetida no formato PDF (Portable Document Format) e o arquivo não deve estar protegido. Por favor, corrija o arquivo PDF e realize uma nova submissão com o arquivo desprotegido. Agradecemos a compreensão on 2017-10-11T13:19:14Z (GMT) / Submitted by Elisa Fonseca Horta null (elisafhort@hotmail.com) on 2017-10-18T23:17:23Z No. of bitstreams: 1 Dissertação Elisa Fonseca Horta.pdf: 1848190 bytes, checksum: a5ac9a5af484d749ce6cad8c93ccd0be (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-10-23T13:08:05Z (GMT) No. of bitstreams: 1 horta_ef_me_rcla.pdf: 1848190 bytes, checksum: a5ac9a5af484d749ce6cad8c93ccd0be (MD5) / Made available in DSpace on 2017-10-23T13:08:05Z (GMT). No. of bitstreams: 1 horta_ef_me_rcla.pdf: 1848190 bytes, checksum: a5ac9a5af484d749ce6cad8c93ccd0be (MD5) Previous issue date: 2017-09-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A degradação anaeróbia é um processo biológico que a partir de uma fonte de carbono gera biogás. Dessa forma, este estudo visou compreender a influência do campo elétrico (ação de cargas elétricas) na degradação anaeróbia da glicose e na geração de biogás em reatores em batelada. Experimentos iniciais foram realizados para determinar as condições ideais de operação (concentração da fonte de carbono e tipo de inóculo). Foram utilizados 4 concentrações de glicose (0,67; 1,00; 2,00 e 10,00g/l) e 3 concentrações de acetato de sódio (0,50; 1,00 e 2,00g/l) para 4 inóculos provenientes de reatores de fluxo ascendente ( 2 de abatedouro de aves, 1 de estação de tratamento de esgoto e uma mistura dos outros 3 lodos). Foram elaborados experimentos com dois meios de cultivo diferentes a fim de identificar o meio nutricional ideal para a geração de metano, meio PYG (genérico para crescimento microbiano) e meio Del Nery (específico para metanogênicas). A próxima etapa foi operar reatores anaeróbios em batelada sob influência do campo elétrico, com utilização de placas paralelas e fonte elétrica com regulagem de tensão, nas condições determinadas pelos experimentos iniciais. As voltagens testadas foram: natural (sem interferência); aterrado (0,0V); 1,5V; 2,0V; 2,5V e 3,0V. As gerações mais elevadas de metano foram observadas para um dos inóculos provenientes do tratamento de águas residuárias de avicultura; a concentração de 2,00 g/l de glicose e o meio PYG. Em todos os reatores com voltagem induzida (de 1,5V a 3,0V) houve eletrólise da água. O reator de 1,5V foi o que obteve os melhores resultados na geração de biogás, apresentando aumento de 200% na geração de metano em comparação com o reator natural, e na remoção da DQO (demanda química de oxigênio), que foi de 93,96% da concentração inicial dos ensaios (5,00g/l). Concluiu-se que o campo elétrico teve influência positiva na degradação anaeróbia para a condição de 1,5V. / The anaerobic degradation process turns a carbon source into biogas. Thus, this study aims to understand the influence of the electric field (action of electric charges) on the anaerobic degradation of glucose and on the generation of biogas in batch reactors. Initial experiments were performed to determine the ideal operating conditions (carbon source concentration and inoculum type). Four concentrations of glucose (0.67, 1.00, 2.00 and 10.00 g/l) and 3 concentrations of sodium acetate (0.50, 1.00 and 2.00 g/l) were used for 4 inoculum from upflow reactors (2 from poultry slaughterhouse, 1 from sewage treatment plant and a mixture of the other 3 sludge). Experiments were carried out with two different culture media in order to identify the ideal nutritional medium for the generation of methane, PYG medium (generic for microbial growth) and Del Nery medium (specific for methanogenic). The next step was to operate anaerobic reactors in batch under the influence of the electric field, using parallel plates and an electric source with voltage regulation, under the conditions determined by the initial experiments. The tested voltages were: natural (no interference); grounded (0,0V); 1.5V; 2.0V; 2.5V and 3.0V. Higher generations of methane were observed using one of the inoculum sourced from poultry wastewater; the concentration of 2.00 g/l glucose and the PYG medium. In all reactors with induced voltage (from 1.5V to 3.0V) there was electrolysis of the water. The 1.5V reactor obtained the best results in the biogas generation, presenting a 200% increase in the methane generation in comparison to the natural reactor and in the removal of COD (Chemical Oxygen Demand), which was 93,96% of the initial assay concentration (5.00 g/l). In conclusion, the electric field had a positive influence on the anaerobic degradation for the 1.5V condition.

A amora-preta (Rubus sp.) faz parte do grupo das chamadas “pequenas frutas” e apresenta propriedades nutricionais relevantes, como elevados conteúdos de sais minerais, vitaminas e compostos bioativos com atividades biológicas. Tais compostos podem auxiliar na prevenção de doenças cardiovasculares, câncer, retinopatia diabética, doença fibrocística e desordens da visão entre outros males. No entanto, a fruta apresenta estrutura frágil e elevada atividade respiratória o que resulta em vida de prateleira reduzida. Desta forma, é tecnicamente importante o desenvolvimento de produtos derivados que mantenham as propriedades nutricionais e compostos bioativos da fruta. Nesse sentido, o presente trabalho teve como objetivo o aproveitamento tecnológico da amora-preta no desenvolvimento de vinagres através dos processos submerso e lento com ciclos sucessivos de acetificação. Inicialmente foi produzido fermentado alcoólico em biorreator de bancada e na sequência foram produzidos fermentados acéticos em vinagreira de grápia e biorreator de bancada. Na fermentação alcoólica foi empregada cepa industrial de Saccharomyces cerevisae r.f. bayanus e na fermentação acética, cepas selvagens de bactérias ácido-acéticas isoladas de vinagre colonial no município de Pato Branco. No processo de fermentação alcoólica foram observados rendimento de 0,39 g/g, produtividade volumétrica em etanol de 1,77g/Lh e eficiência de 75,5%, bem como elevados conteúdos de polifenóis (983,35 mg GAE/100g e 1.702,52 mg GAE/100g). Nos ciclos sucessivos de acetificação conduzida em vinagreira foi obtida produção média de 51,6 g/L de ácido acético, rendimento em ácido acético de 72,2% e produtividade volumétrica de 0,4 g/Lh. Por outro lado, menores valores de produção média de ácido acético (42,26 g/L) e rendimento (70,2%) foram observados no processo de acetificação conduzido em biorreator de bancada. Elevados conteúdos de polifenólicos, antocianinas e elevada atividade antioxidante foram obervados nos vinagres obtidos em ambos os processos de produção. Os vinagres produzidos a partir de amora-preta podem ser considerados vinagres do tipo gourmet que apresentam potencial funcional e a transformação da fruta em vinagre pode ser uma estratégia de agregação de valor a cadeia produtiva colaborando para disseminação da cultura no Brasil. / Blackberry (Rubus sp) is part of the so-called berries, presenting remarkable nutritional features, such as high content of mineral salts, vitamins and bioactive compounds with biological activity. Such compounds may aid in the prevention of cardiovascular diseases, cancer, diabetic retinopathy, fibrocystic and eye diseases, among others. Nevertheless, blackberry presents a fragile structure and a high respiratory activity, resulting in reduced shelf-life. In this way, it is important, from a technological viewpoint, to develop new products derived from blackberry which preserve the fruit original nutritional quality and bioactive compounds. Thus, the present work aimed at the technological utilization of blackberry for developing vinegar by means of the submerged and the slow processes with successive cycles of acetification. Initially, an alcoholic fermented product was obtained in stirred tank bioreactor. Subsequently, acetic fermented products were obtained either in a grapia (Brazilian ash) vinegar barrel or in a bench bioreactor. In the alcoholic fermentation, an industrial strain of Saccharomyces cerevisiae r.f. bayanus was used. In the acetic fermentation, wild strain of acetic acid bacteria isolated from colonial vinegar from Pato Branco city was used. The alcoholic fermentation presented yield of 0.39 g/g, volumetric productivity of 1.77 g/Lh and efficiency of 75.5%, besides high polyphenol contents (983.35 mg GAE/100g and 1702.52 mg GAE/100g). In the successive acetification cycles performed in grapia barrel, average production of 51.6 g acetic acid/L, yield of 72.2% (as acetic acid) and volumetric productivity of 0.4 g/Lh were observed. On the other hand, the acidification performed in bench bioreactor presented lower values of average production (42.26 g acetic acid/L) and yield (70.2%). High polyphenols and anthocyanins content along with high antioxidant activity were observed in the vinegars obtained by both production processes. Vinegars produced from blackberry can be considered gourmet vinegars with high functional potential. The transformation of blackberry into vinegar might be a strategy of value addition to the production chain, contributing for spreading this culture in Brazil.

Grãos de café, da espécie Coffea canephora variedade conilon foram submetidos a um tratamento com vapor de água e solução ácida de acordo com um delineamento experimental utilizando-se a metodologia do Delineamento Central Rotacional (DCCR). As variáveis selecionadas para o planejamento experimental foram a pressão do vapor, a concentração da solução ácida e o tempo de contato com o vapor. Neste delineamento 17 testes foram propostos incluindo o ponto central com 3 repetições. A análise dos dados foi feita empregando-se o programa Statistica versão 10.0, pela análise ANOVA para avaliação do nível de significância e avaliação do modelo, além da geração de superfícies de resposta para indicação da influência das variáveis nos resultados obtidos. Os grãos foram torrados e analisados quanto ao teor de polifenóis, pH, acidez titulável, cafeína e compostos aromáticos. Os compostos aromáticos analisados foram divididos em dois grupos, os que contribuem positivamente e os que contribuem negativamente para o aroma do café. Para análise de polifenóis totais e cafeína foi utilizada a técnica de cromatografia líquida de alta performance e detector com arranjo de fotodiodos (HPLC/DAD) e para análise dos compostos aromáticos, cromatografia gasosa acoplada a espectrometria de massas (GC/MS). Os resultados indicaram que em valores mais altos das variáveis pressão de vapor e tempo de contato com o mesmo, a acidez titulável sofreu redução mesmo com concentrações maiores de solução ácida aplicada. A cafeína apresentou resultados máximos para as condições de 0,8 Bar para pressão de vapor, 12 minutos de tempo de contato com o vapor e concentração da solução ácida entre 5,0 a 7,0%. Os maiores resultados para os compostos aromáticos positivos foram nas condições de concentração do ácido entre 6 a 8%, pressão de vapor entre 0,4 a 0,6 Bar e tempo de contato entre 24 a 26 minutos, compostos aromáticos negativos apresentaram valores mínimos em concentração de ácido entre 0 a 1%, pressão entre 0,4 a 0,8 Bar, e tempo de contato entre 18 a 20 minutos. A análise estatística dos resultados evidenciou que polifenóis e pH foram significativamente influenciados pela variação do grau de torra, não permitindo a obtenção de modelos preditivos pelo delineamento experimental. / Coffee beans, species Coffea canephora variety conilon were submitted into a treatment with water steam and acid solution by an experimental design, which was generated using the methodology of the central composite rotational design (DCCR). The selected variables to the experimental design were steam pressure, acid solution concentration and time of coffee bean's contact with steam. In this design seventeen tests were proposed including the central point with three repetitions. The results obtained were processed in Statistica software version 10.0, by ANOVA tables that were used for assessing the level of significance and model, beyond the generation of response surfaces to indicate the influence of the variables in the final result. Coffee beans samples were roasted and analyzed for polyphenol content, pH, titratable acidity, caffeine and aromatic compounds. The aromatic compounds analyzed were divided into two groups, those that contribute positively or negatively to coffee flavor. Analysis of total polyphenols and caffeine were done by high performance liquid chromatography with a photodiode array detector (HPLC / DAD) and for analysis of aromatic compounds, gas chromatography -mass spectrometry (GC / MS). The results indicated that in higher values of steam pressure and contact time with the same, the titratable acidity decreased even with higher concentrations of acid solution applied. Caffeine showed maximum results for conditions of 0.8 bar to steam pressure, 12 minutes of contact with steam and acid solution concentration between 5.0 to 7.0 %. The higher results for the positive aromatic compounds were the conditions of acid concentration between 6 to 8 %, steam pressure between 0.4 to 0.6 bar and the contact time between 24 to 26 minutes, negative aromatic compounds showed minimum values in acid concentration between 0 to 1 %, steam pressure between 0.4 to 0.8 bar, and the contact time between 18 to 20 minutes. The statistical analysis showed that polyphenols and pH were significantly influenced by the variation of the roasting degree, not allowing to obtain predictive models by experimental design.