Current US government risk assessment and management regulations and policies are based on a position that views risk as an objective measure of a predictable physiological morbidity or mortality outcome that is not otherwise connected to social or cultural beliefs and values. Whereas human health risk assessments are meant to determine the probability of adverse impacts from particular hazards, the conventional risk assessment framework fails to consider Native American definitions of health and so risk. This study was conducted with the Coast Salish Swinomish Indian Tribal Community of Washington State, where contamination of their aquatic natural resources has been found. By conducting two series of interviews with traditional high-use seafood consumers, experts and elders from the Swinomish Indian Tribal Community, and by averting use of what I describe herein as ‘conventional’ fish consumption survey, the study allowed interviewees to provide a more complex narrative set of details and information that bestowed a much more accurate picture of the reasoning behind seafood consumption habits within the community. Among the more salient points that emerged from the interviews was that seafood represents a symbolic, deeply meaningful food source that is linked to a multi-dimensional ‘Swinomish’ concept of health. Yet drastic changes in access, harvest and consumption have occurred over time, and continue to this day. A health evaluation tool was also devised using simple descriptive scaled rankings to elucidate non-physiological health risks and impacts in relation to contaminated seafood. Findings demonstrate that community cohesion, food security, ceremonial use and knowledge transmission all play primary roles as concerns the Swinomish notions of health, and that these indicators are regarded as equally important when juxtaposed to physical indicators of health. Thus, to eat less seafood—as prescribed by current policy and decision-making procedures when contamination is present—is actually detrimental to the multi-dimensional concept of health as defined by the Swinomish. The evaluation tool may be used in conjunction with the conventional risk assessment framework to more accurately and comprehensively deduce risks and impacts. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

VANETs are the essential component of the intelligent transport system, which attract research and industrial interests increasingly. As the multifunctional mobile nodes integrating transporting, sensing, information processing, and wireless communication capabilities, vehicular nodes are facing remarkable security issues and more vulnerable to malware attack than conventional communication nodes. In this thesis, the behavior and the security issues of the worm spreading on VANETs are studied. The approaches of the worm spreading on VANETs are discussed and an infrastructure based worm containment strategy is proposed. The infrastructure based worm containment problem is modeled as minimum contamination problem by introducing the expected contamination degree. Then the existing greedy method is applied to solve the proposed problem in VANETs scenario. After that, the Grid-shrinking Greedy Method and the Simplified Greedy Method are proposed which incorporate the characteristics of road networks and VANETs respectively. Simulation results show the two proposed methods outperform the existing greedy method and the comparison method from both complexity and solution quality aspects.

Des contaminations par Enterobacter gergoviae, dans les formulations cosmétiques diverses soulèvent le problème de la résistance bactérienne aux biocides. J'ai pu mettre en évidence, que certains épisodes de contaminations apparus au sein de l'entreprise partenaire, étaient dus à un même isolat persistant suite à un système de conservation/désinfection inefficace. Aux concentrations maximales autorisées par la commission européenne, les conservateurs ont des effets bactériostatiques mais ne présentent pas d'effets synergiques en association. Par conséquent, l'adaptation aux produits cosmétiques est favorisée. Divers mécanismes de résistance peuvent être mis en place par E. gergoviae : enzymatique (synthèse de peroxyredoxine), modifications de l'enveloppe (expression d'appendices externes : flagelles ou fimbriae/pili), modification de la mobilité, et formation de biofilms. L'apparition de ces mécanismes a aussi favorisé les résistances croisées conservateurs /désinfectants-détergents. / Contaminations by Enterobacter gergoviae in various cosmetic formulations raise the problem of bacterial resistance to biocides of the species, which represent the third source of cosmetics bacterial contaminations. The collaborative cosmetic company was concerned by unrelated contaminations but some contamination events were due to persistence of isolates in internal system process, despite disinfection protocols and use of preservatives. At the maximum levels allowed by the European Commission, preservatives tested have bacteriostatic effects and do not exhibit synergistic effects in combination. Therefore, adaptation in cosmetics is facilitated. Various resistance mechanisms can be implemented by E. gergoviae: Enzymatic (peroxyredoxin synthesis), changes in the envelope (expression of external appendages: flagella or fimbriae/pili), changes in mobility and biofilm formation. The appearance of such mechanisms has also promoted a cross-resistance conservative / disinfectant - detergent.

Overhead conductors used in the transmission of power in grids around the world are generally subjected to ageing, which is the time-based change of their properties. Important properties such as corona discharge, audible noise, hydrophobicity and corrosion are usually considered and investigated. On some conductors such as the aluminium conductor steel reinforced (ACSR), a reduction in audible noise over exposure time to the service environment has been noted to occur. However, the converse has been observed for the gap-type thermal resistant aluminium conductor steel reinforced (GTACSR or “Matthew” conductor), although this conductor is preferred due to its high ampacity. The relationship between conductor hydrophobicity, audible noise, surface contamination and roughness, wettability and corrosion were investigated using All Aluminium Alloy Conductor (AAAC), Aluminium Conductor Composite Core (ACCC) and GTACSR samples. Findings from Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectric Spectroscopy (XPS) and contact angle measurements revealed that carbon, hydrocarbon and silicone contamination was responsible for the hydrophobic nature of the surface. Furthermore, electrochemical investigations and electron microscopy showed that pitting or/and crevice corrosion were the predominant corrosion mechanisms on these conductors. Exposure to simulated industrial and marine environments further confirmed this finding and also showed that general corrosion also occurs on relatively uncontaminated conductors, thereby changing their surface roughness, as seen from the White Light Interferometry results. Corrosion was observed to be accelerated by the presence of surface contaminants such as oils and carbon, as these facilitated water (droplet) retention by reducing the conductor’s surface energy. Reduction/elimination of surface contamination/hydrophobicity were the desired solutions to the problem, and this was achieved by grit blasting. Partial/complete oxidation of the silicones resulted in the reduction/elimination of sample hydrophobicity – this was seen from more contact angles measurements and XPS data. Grit blasting also restored conductor cleanliness and roughened the surface sufficiently to produce surface run-off.

Two hybridoma clones, labelled 4D10 C1 and 2H4 H12, produced monoclonal antibodies which recognized the outer membrane of an enteropathogenic Escherichia coli (EPEC) 0142:K86:H6 in an enzyme-linked immunosorbent assay (ELISA) and the whole cell in an immunofluorescence assay. Large scale production of the monoclonal antibodies was accomplished through ascites production in balb/c mice. Purification of the ascites fluid was achieved by gel filtration and ion exchange chromatography. Isotyping of the purified fractions showed 4D10 C1 to be an IgG2 and 2H4 H12 an IgM. These monoclonal antibodies were screened by immunofluorescence assay against several pathogenic and nonpathogenic strains of E.coli in addition to other Enterobacteriaciae. Results of the screening showed these antibodies to be specific for the E.coli serotype to which they were raised. Minimal cross-reactivity with other Enterobacteriaceae was observed. In a separate and concurrent project, the use of an ELISA capable of detecting ß-N-acetylglucosaminidase (NAGase) was examined. White Leghorn hens were injected with commercially prepared bovine NAGase. Eggs were collected and the immunoglobulin fraction separated from the egg yolk by polyethylene glycol precipitation followed by ion exchange on a DEAE-Sephacel column. The use of the purified immunoglobulins was examined in a sandwich, double-sandwich and a competitive ELISA. A statistically significant standard curve for the detection of NAGase was successfully derived using a double-sandwich ELISA when rabbit immunoglobulin was used to coat the microwell plates. This assay was used to measure the NAGase concentration in press juice and fish extract of fresh and frozen salmon muscle samples. The ratio of the NAGase concentration in the press juice to the total NAGase concentration was compared. No significant difference was found between the calculated concentration ratios of the fresh muscle samples and samples frozen for 1 week at -20°C. / Land and Food Systems, Faculty of / Graduate

Teores anômalos de cromo hexavalente vêm sendo detectados na água subterrânea de vários municípios da região noroeste do Estado de São Paulo, sendo que em Urânia foram observadas as maiores concentrações do elemento, afetando as condições do consumo e uso humano. Estudos prévios realizados indicaram que a origem do cromo na água subterrânea é natural e proveniente de minerais com cromo no aqüífero profundo. Este projeto teve como principais objetivos: (1) a caracterização química e mineralógica da fase sólida do aqüífero profundo, realizada em testemunhos de duas sondagens profundas; (2) a caracterização da estratificação das concentrações de cromo na água subterrânea, com base na coleta e análise de amostras de água provenientes de poços de monitoramento instalados em diferentes profundidades do aqüífero; (3) a identificação dos processos hidrogeoquímicos que justificam a passagem do cromo da fase sólida para a água. Para tanto, foram realizadas análises químicas e mineralógicas por WDS, microssonda eletrônica e CTC, diversos métodos de análise química da água subterrânea, utilizados programas como o AquaChem e PHREEQc para trabalhamento do banco de dados e modelagens, além de uma grande variedade de experimentos de laboratório. As análises químicas por WDS e microssonda eletrônica indicaram concentrações de cromo de até 12.600 ppm em cristais de diopsídio, e de 650 ppm em capas de argilomineral. O material sólido apresenta uma capacidade de troca de cátions da ordem de 30 meq/100g, com ordem de abundância dos cátions Ca>>Mg>>K>Na. Na porção profunda do aqüífero, foi observada uma anomalia de sódio adsorvido, influenciando na composição química da água. As características hidroquímicas do aqüífero indicaram a ocorrência de estratificações de águas com diferentes perfis hidroquímicos. As águas são, no geral, do tipo bicarbonatadas cálcicas, porém com uma elevação do conteúdo de sódio na base do aqüífero. O cromo foi identificado na água predominantemente na forma hexavalente, com concentrações que atingiram 0,139 mg/L, acima, portanto do limite de potabilidade (0,05 mg/L). A ocorrência de valores mais elevados de cromo na água parece estar associada a ambientes de elevados pH e Eh, como observado no aqüífero profundo, enquanto que nas zonas rasas, que apresentam valores de pH e Eh neutros, apresentaram baixo conteúdo de cromo. Os principais resultados dos ensaios de laboratório indicaram que há passagem de cromo para água subterrânea, através do ataque aos minerais pesados com pH ácido; os ensaios de batch test realizados apontaram que o material sólido do aqüífero apresenta alguma capacidade de adsorção de Cr6+, chegando a um máximo de 0,12 ppm; o experimento de solubilização indicou a passagem de pequenas concentrações de cromo para a água e que a composição química da água do ensaio é semelhante à água do aqüífero. O modelo mais provável das reações geoquímicas que explicam a passagem do cromo da fase sólida para a água é apresentado a seguir, divido por etapas: (1) o intemperismo dos diopsídios cromíferos deve ser o processo inicial de disponibilização de cromo para a água, resultando na precipitação do cromo como hidróxidos ou sendo adsorvido por hidróxidos de ferro e manganês; (2) ocorrência de uma reação de oxi-redução a partir do cromo trivalente que ocorre nos minerais secundários, disponibilizando o cromo para a água subterrânea, sendo que esta oxidação ocorre a partir da redução de óxidos de manganês presentes como minerais em aqüíferos, liberando Mn2+; (3) O Cr3+ é rapidamente e fortemente imobilizado por adsorção em argilominerais de baixo valor de pHpzc, enquanto que o Cr6+, devido à sua natureza aniônica, é preferencialmente retido em superfícies carregadas positivamente, como os óxidos e hidróxidos de ferro e alumínio (minerais com elevados valores de pHpzc), principalmente em condições hidroquímicas neutras a ácidas; (4) altas concentrações de OH-, de HCO3- e de CO3 2- provavelmente elevam a competição pelos sítios de adsorção de ânions e causam a dessorção dos ânions de Cr6+ para a água do aqüífero. / Anomalous hexavalent chromium contents have been detected in groundwater in many municipalities of the northwestern region of São Paulo state. In the city of Urânia, the highest concentrations of this element have been observed, affecting the conditions for human consumption. Previous studies indicated that the origin of chromium in groundwater is from natural sources and derived from chromium minerals in the deep aquifer. The main objectives of this research are to: (1) characterize chemically and mineralogically the solid phase from the deep aquifer; (2) characterize the stratification of chromium concentrations in groundwater, based on sampling and analysis of groundwater from wells installed in different depths of the aquifer; (3) identify hydrogeochemical processes that justify the passage of chromium from solid phase to groundwater. To achieve these objectives, chemical and mineralogical analysis by WDS, microprobe and CEC were made, diverse chemical analytical methods were used for groundwater, database and modeling were used through AquaChem and PHREEQc programs, besides a great variety of laboratory experiments. Chemical analysis from WDS and microprobe indicated chromium concentrations of up to 12.600 ppm in diopside crystals, and up to 650 ppm in clay mineral coats. The solid material has a Cation Exchange Capacity (CEC) of about 30 meq/100g, with cation abundance order of Ca>>Mg>>K>Na. In the aquifer deep zone, it was observed an adsorbed sodium anomaly, that influences groundwater chemical composition. The aquifer hydrochemical characteristics indicated the occurrence of water stratifications with different hydrochemical profiles. The groundwaters are, in general, calcium bicarbonated, with a elevation of sodium contents in the base of the aquifer. Chromium was identified predominatly in hexavalent state of oxidation, with concentrations of up to 0,139 mg/L, thus above potability standards (0,05 mg/L). The occurrence of higher chromium concentrations in groundwater seems to be related to high pH and Eh environments, whereas shallow zones, that have neutral values of pH and Eh, presented low chromium contents. The main results of laboratory experiments have indicated that there is passage of chromium to groundwater through acid etching in heavy minerals; batch tests have shown that solid phase has some sorption capacity, reaching a maximum of 0,12 ppm; solubilization experiment indicated the passage of low concentrations of chromium to water and that chemical composition from the experiment water is similar to groundwater. The probable model that explain the passage of chromium from solid phase to groundwater is presented hereafter, divided in steps: (1) it is indicated that weathering of chromium diopsides must be the initial process of availability of chromium to water; (2) hexavalent chromium can only occur in groundwater after the occurrence of an oxi-reduction reaction from the trivalent chromium that occurs in minerals. Many authors recognize that this oxidation occurs from the reduction of manganese oxide presented as minerals in the aquifer, releasing Mn2+, that later will be oxidated again; (3) the trivalent chromium is rapidly and strongly immobilized by sorption in clay minerals of low values of pHzpc, whereas the hexavalent chromium, due to its anionic nature, is preferably retained in positively charged surfaces, like iron and aluminium hydroxides (minerals with high values of pHzpc), mainly in neutral to acid hydrochemical conditions; (4) high OH-, HCO3 - and CO3 2- concentrations probably elevate the competition for anion sorption sites and cause the desorption of hexavalent chromium anions to groundwater.

Submitted by Adriana Martinez (amartinez@unoeste.br) on 2017-10-23T11:44:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Letícia.pdf: 5591928 bytes, checksum: 2cba7167a042b5176b457d4b899e2add (MD5) / Made available in DSpace on 2017-10-23T11:44:35Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Letícia.pdf: 5591928 bytes, checksum: 2cba7167a042b5176b457d4b899e2add (MD5) Previous issue date: 2017-03-10 / Cemeteries are intrinsic to society and need to be analyzed in order to provide a harmonious relationship with the environment, minimizing the impacts that this activity can generate. According to the contamination potential of the cemeteries, and the changes in the physical and biotic spheres, a potential environmental impact is attributed to cemetery activity. The liquid released by the decomposition of the corpses, the necrochorume, is the main cause of environmental pollution by the cemeteries. The present work had as objective to carry out a historical survey of the cemeteries of Presidente Prudente; to analyze the water quality of water bodies near cemeteries; as well as to analyze the biodiversity of plant species and birds. The research methodology consisted of a bibliographical survey regarding the history of cemetery activity, burial forms and environmental impacts of cemeteries. Physical-chemical and microbiological analyzes were carried out on surface water samples collected at points near the cemeteries, in addition to the survey of plant and bird species present in the cemeteries. From the results obtained through fieldwork, laboratory and literature reviews it was possible to identify that the cemeteries of the municipality of Presidente Prudente-SP can generate negative environmental impacts on the environment, causing contamination of water resources. Biodiversity is not satisfactory, so it is recommended variation of the tree species to guarantee the biodiversity of the place and potentially attract more bird species. / Os cemitérios são intrínsecos à sociedade e precisam ser analisados a fim de proporcionar uma relação harmoniosa com o meio ambiente, minimizando os impactos que essa atividade pode gerar. De acordo com a potencialidade de contaminação dos cemitérios, e as alterações nos meios físico e biótico, é atribuída à atividade cemiterial um potencial impacto ambiental. O líquido liberado pela decomposição dos cadáveres, o necrochorume, é a principal causa da poluição ambiental pelos cemitérios. O presente trabalho teve como objetivo realizar um levantamento histórico dos cemitérios de Presidente Prudente, analisar a qualidade da água de corpos hídricos próximo aos cemitérios, bem como analisar a biodiversidade de espécies vegetais e aves. A metodologia de pesquisa consistiu no levantamento bibliográfico sobre o histórico da atividade cemiterial, as formas de sepultamento e os impactos ambientais dos cemitérios. Análises físico-químicas e microbiológicas foram executadas em amostras de água superficiais, coletadas em pontos próximos dos cemitérios e o levantamento das espécies vegetais e aves presentes nos cemitérios também foram realizados. A partir dos resultados obtidos por meio de trabalhos de campo, laboratoriais e revisões de literatura foi possível identificar que os cemitérios do município de Presidente Prudente-SP podem proporcionar impactos ambientais negativos no meio ambiente, causando contaminação dos recursos hídricos. A biodiversidade não é satisfatória, por isso recomenda-se variação das espécies arbóreas para garantir a biodiversidade do local, podendo atrair dessa forma mais espécies de aves.

As contaminações por leveduras selvagens e por bactérias no processo de produção de etanol combustível no Brasil causam prejuízos ao rendimento fermentativo e aumento de custos pelo uso de biocidas. No entanto, poucos estudos tem focado no efeito das contaminações conjuntas de leveduras selvagens e bactérias e as possíveis interações entre os micro-organismos, especialmente em função dos diferentes substratos de fermentação e das formas de controle. Este trabalho teve por objetivos verificar o efeito do substrato (caldo de cana e melaço) sobre o desenvolvimento das contaminações pela levedura da espécie Dekkera bruxellensis e pela bactéria Lactobacillus fermentum, em co-culturas com Saccharomyces cerevisiae (linhagem industrial PE-2) e possíveis formas de controle do crescimento dos contaminantes (pelo uso de metabissulfito de potássio e adição de etanol ao tratamento ácido) sem afetar a levedura do processo. Os testes foram realizados em condições de crescimento (substrato com 4 °Brix, culturas agitadas) e fermentação com reciclo celular (substrato com 16 °Brix, culturas estáticas). Houve interação entre as leveduras e a bactéria quando crescidas em caldo de cana 4 °Brix. A levedura industrial não foi afetada pela presença dos micro-organismos contaminantes, no entanto, para D. bruxellensis a presença de L. fermentum interferiu positivamente no crescimento, com aumento no número de UFC, e consequentemente inibição do crescimento da bactéria. Em melaço, houve um estímulo ao crescimento de L. fermentum quando em co-cultura com S. cerevisiae. Houve influência das contaminações sobre os parâmetros avaliados no experimento (pH, açúcar redutor total, etanol, glicerol e crescimento das células) e a contaminação conjunta de L. fermentum e D. bruxellensis potencializou o efeito das contaminações pelos micro-organismos isoladamente, tanto em caldo quanto em melaço. A adição de 13% de etanol à solução de ácido sulfúrico pH 2,0 no tratamento celular resultou em uma diminuição significativa no número de UFC de D. bruxellensis (entre 90-99%). A levedura PE-2 foi pouco afetada pelo tratamento proposto. A bactéria L. fermentum teve seu crescimento afetado em todas as combinações testadas. Como os experimentos foram feitos em co-culturas, verificouse que pode haver influência de um micro-organismo sobre a viabilidade do outro, dependendo da reação ao tratamento ácido-etanol. O metabissulfito de potássio (MBP), no intervalo entre 200-400 mg/L, foi eficaz para controlar o crescimento de D. bruxellensis dependendo do meio de cultura e linhagem. Quando adicionado (250 mg/L) à solução ácida (pH 2,0) no tratamento celular, um efeito significativo foi observado nas culturas mistas, pois ocorreu a inativação do SO2 pela S. cerevisiae e uma provável proteção das células de D. bruxellensis, não sendo essa levedura prejudicada pelo MBP. A resposta fisiológica de S. cerevisiae na presença de MBP pode explicar a diminuição significativa na produção de etanol. Quando o MBP foi adicionado ao meio de fermentação, resultou no controle da D. bruxellensis mas não em sua morte, com efeito menos intensivo sobre a eficiência fermentativa. Em cocultura com a adição de MBP, a eficiência fermentativa foi significativamente menor do que na ausência de MBP. / The contaminations by wild yeasts and bacteria are harmful to the fermentative process for fuel ethanol production in Brazil due to the decrease in ethanol yield and increase in the industrial costs by the use of biocides. However, a few studies have been focused in the effects of simultaneous contaminations of wild yeasts and bacteria and the possible interactions among the microorganisms, especially concerning different fermentation substrates and forms of growth control. This work aimed to verify the effect of the substrate (sugar cane juice and molasses) on the development of contaminations by Dekkera bruxellensis yeast and Lactobacillus fermentum bacteria, in co-cultures with Saccharomyces cerevisiae (industrial strain PE-2) and possible forms of growth control of the contaminants (using potassium metabisulphite and addition of ethanol to the acid treatment) without affecting the starter yeast. Tests were carried out in growing conditions (substrate with 4 °Brix, shaken cultures) and cell-recycled fermentation (substrate with 16 °Brix, static cultures). There was interaction among the yeasts and the bacteria when growing in sugarcane juice 4 °Brix. The industrial yeast strain was not affected by the presence of the contaminant microorganisms, however, for D. bruxellensis, the presence of L. fermentum influenced positively the growth, increasing the number of CFU and consequently inhibiting the bacterial growth. In molasses, there was an increase in the growth of L. fermentum when in co-culture with S. cerevisiae. The contaminations influenced the fermentative parameters (pH, total reducing sugars, ethanol, glycerol and cell growth) and the simultaneous contamination by L. fermentum and D. bruxellensis potentiated the effect of the contaminations isolately, both in sugarcane juice as in molasses. The combined effect of pH 2.0 + 13% ethanol in the cell treatment resulted in a significant decrease (90-99%) in the CFU number of D. bruxellensis. The industrial yeast PE-2 was a little affected by the treatment. The growth of the bacteria L. fermentum was affected in all the combinations tested. As the experiments were performed with co-cultures, an influence of a microorganism over the viability of another was observed, depending of the reaction to the treatment. The potassium metabisulphite (PMB), in the range of 200-400 mg/L, was effective to control the growth of D. bruxellensis depending on the culture medium and strain. When added (250 mg/L) to the acidic solution (pH 2.0), a significant effect was observed in mixed cultures, because the inactivation of SO2 by S. cerevisiae most likely protected D. bruxellensis from being damaged by PMB. The physiological response of S. cerevisiae to the presence of PMB may explain the significant decrease in alcohol production. When added to the fermentation medium, PMB resulted in the control but not the death of D. bruxellensis, with less intensive effect on the fermentative efficiency. In co-culture with the addition of PMB, the fermentative efficiency was significantly lower than in the absence of PMB.

No presente trabalho foram realizadas análises de enterobactérias e Salmonella em cecos e papos de frangos de corte criados sem reaproveitamento de cama e com baixa densidade, submetidos a períodos de jejum de 3, 6, 9, 12, 15 e 18 horas; também foram feitas análises das mesmas bactérias, incluindo esporos de Bacillus subtilis e bactérias ácido lácticas em papos e cecos de frangos de corte alimentados com probióticos (bactérias lácticas, Bokashi e esporos de B. subtilis) e antibiótico (bacitracina de zinco) nas rações. Não houve diferença significativa entre as populações de enterobactérias nos períodos de jejum analisados, e não foram isoladas cepas de Salmonella nos diferentes tratamentos. Houve diminuição significativa na população de enterobactérias nos cecos em relação ao grupo controle quando os frangos foram alimentados com bactérias ácido lácticas nas rações. Com Bokashi e antibiótico nas rações, a população de enterobactérias nos cecos foi maior que no grupo controle. Nos papos, não houve diferença significativa entre as populações de enterobactérias para os diferentes tratamentos, mas o tratamento com Bokashi foi o que obteve menor população das enterobactérias nesse habitat. As contagens de bactérias ácido lácticas e esporos de B. subtilis dos cecos e papos analisados não sofreram alteração significativa devido aos diferentes aditivos presentes nas rações, quando comparadas ao grupo controle. Novamente não foram isoladas cepas de Salmonella nos cecos e papos dos frangos analisados. A ausência de Salmonella pode ter explicação no modo de criação dos frangos, com baixa densidade (12 aves/m2) e sem reaproveitamento de cama, pois foi um resultado encontrado nas duas fases do trabalho. A diminuição de enterobactérias nos cecos por parte das bactérias ácido lácticas administradas na ração pode ter sido devido à exclusão competitiva, apesar da população dessas bactérias não ter aumentado significativamente neste habitat. O tratamento com administração de Bokashi obteve menor contagem de enterobactérias no papo possivelmente devido ao fato de ser um produto fermentado, com pH baixo, que poderia agir prontamente no papo. A administração de esporos de B. subtilis não surtiu efeito nas populações das bactérias analisadas nos cecos e papos dos frangos de corte. / This study analyzed the population of enterobacteria and Salmonella in the crop and caeca of broiler chickens submitted to 3, 6, 9, 12, 15 and 18 hours of feed withdrawal, and raised without reutilization of the litter, in low density. The same bacteria were analyzed, plus Bacillus subtilis spores and lactic acid bacteria, in the crop and caeca of broiler chickens fed rations with probiotics (lactic acid bacteria, Bokashi and B. subtilis spores) and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and Salmonella and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and B. subtilis spores populations from the caeca and crops of analyzed broiler chickens did not differ from the control group when the different additives were fed through the ration. Again there were no Salmonella isolates in the analyzed crop and caeca. The absence of Salmonella may have an explanation on the way that chickens were raised, with low density (12 birds/m2) and no litter reutilization, because this result was found on the two phases of the study. The lower caeca enterobacteria population found when the broilers were fed lactic acid bacteria may have been due to competitive exclusion, even though the lactic acid bacteria counting did not increase significantly in this habitat. Treatment with Bokashi administration had lower counting of enterobactérias in the crop, possibly due to the fact that Bokashi is a fermented product, with low pH, that could act readily in the crop. The administration of B. subtilis spores did not have any effect on the populations of the analyzed bacteria, in the crop and caeca of broiler chickens.

A espécie Dekkera bruxellensis tem sido detectada como a principal levedura contaminante em diversos processos fermentativos, dentre eles o de produção de etanol combustível, apresentando uma surpreendente capacidade de crescimento e adaptação naqueles substratos. No entanto, pouco se conhece sobre suas características de crescimento em condições de estresse e comportamento fermentativo. Desta forma, este trabalho objetivou avaliar a tolerância ao estresse e as características fermentativas exibidas por três linhagens de D. bruxellensis isoladas da fermentação alcoólica, além do efeito da contaminação em mosto de caldo de cana sobre os parâmetros fermentativos, buscando informações que possam contribuir para o manejo da fermentação alcoólica quando contaminada com esta levedura. Foram realizados testes de caracterização em meio YEPD sólido e líquido em condições estressantes para as três linhagens de D. bruxellensis e uma linhagem de S. cerevisiae (PE-02). O efeito do tratamento ácido associado ao etanol sobre a viabilidade das quatro linhagens em situação de agitação e sem agitação foi também avaliado. Em seguida, testes fermentativos em meio sintético (sem reciclo celular) e em meio de caldo de cana (com reciclo celular e utilizando-se ou não tratamento ácido) foram conduzidos para verificar as características fermentativas das linhagens de D. bruxellensis em comparação com S. cerevisiae, simulando-se uma contaminação por 103 células/mL da linhagem CCA155 em meio de caldo de cana. As três linhagens de D. bruxellensis apresentaram crescimento invasivo em meio YEPD sólido, possivelmente um mecanismo de sobrevivência da levedura em condições estressantes. Observou-se uma variação na resposta das linhagens às situações de estresse (baixo pH e alta concentração de etanol). Em condições não estressantes, a linhagem PE-02 apresentou melhor desenvolvimento, no entanto, em situações de estresse de pH, concentrações de açúcar e etanol, as linhagens de D. bruxellensis desenvolveram-se melhor. O controle eficiente do crescimento destas leveduras poderia ser obtido com um tratamento combinado de baixo pH (1,5) e etanol (9%), porém houve também prejuízo significativo à levedura S. cerevisiae, embora em menor extensão. Em sistema de batelada sem reciclo celular em meio sintético, verificou-se que a agitação influenciou significativamente a produção de etanol e ácidos por D. bruxellensis. O teor alcoólico foi maior quando se utilizou glicose como fonte de carbono ao invés de sacarose. Em sistema de batelada com reciclo celular em meio de caldo de cana, foram obtidos melhores resultados quanto à produção de etanol, menor teor de açúcar redutor total residual e maior eficiência fermentativa quando se utilizou o tratamento ácido do fermento (pH 1,5), assim como melhor controle do crescimento da linhagem CCA155 quando em cultura mista com S. cerevisiae (PE-02). O tratamento ácido utilizado teve efeito não só sobre o crescimento da levedura contaminante, mas também beneficiou a levedura do processo, resultando assim na minimização do efeito da contaminante sobre a fermentação conduzida em meio de caldo de cana sob dez ciclos fermentativos de 12 horas. / The species Dekkera bruxellensis has been considered as the main contaminant yeast in several fermentative processes, including the fuel alcohol production, showing a surprising growth capacity and adaptation in those substrates. However, a little is known about their growth characteristics in stressing conditions and fermentative profile. In this context, this work aimed to evaluate the stress tolerance and fermentative characteristics exhibited by three strains of D. bruxellensis isolated from the alcoholic fermentation, besides the effect of the contamination in sugar cane juice over the fermentative parameters, searching for information that could contribute to the management of the alcoholic fermentation when the medium is contaminated with this yeast. Characterization tests in YEPD medium (solid and liquid) under stressing conditions for the D. bruxellensis and S. cerevisiae (PE-02) strains were carried out. The effect of the acid treatment associated with ethanol over the cell viability of the four strains in shaken and non-shaken flasks was also evaluated. Following, fermentative tests in synthetic medium (without cell recycle) and in sugar cane juice (with cell recycle and with/without acid treatment) were carried out to verify the fermentative characteristics of the strains of D. bruxellensis comparing to S. cerevisiae, simulating a contamination by 103 cells/mL of the strain CCA155 in sugar cane juice. All the strains of D. bruxellensis showed invasiveness in YEPD agar medium, probably a survival mechanism in stressful conditions. A variation in the response of the strains to the stressing conditions (low pH and high ethanol concentration) was observed. In nonstressing situations, the strain PE-02 showed better growth; however, in stressing conditions of pH, ethanol and sugar concentrations, the strains of D. bruxellensis had better growth performance. The effective control of their growth could be obtained with a combined treatment of low pH (1.5) and ethanol (9%), however, a significant harmful effect to the S. cerevisiae strain was also verified, but in a lower extension. In batch system without cell recycle in synthetic medium, it was verified the influence of agitation over the ethanol and acid production by D. bruxellensis. The alcohol content was significantly higher when glucose was utilized instead of sucrose. In batch system with cell recycle in sugar cane juice, the best results for ethanol production, lower residual total reducing sugar and higher fermentative efficiency were obtained with the acid treatment of the ferment at pH 1.5, as well as a better growth control of the strain CCA155, in mixed culture with S. cerevisiae (PE-02). The acid treatment utilized in this work had effect not only over the growth of the contaminant yeast, but also benefited the yeast S. cerevisiae, resulting in the minimization of the effect of the contaminant over the fermentation developed in sugar cane juice medium in 12-hour ten fermentative cycles.