The genotoxicity of energetic compounds (i.e., explosives) that are known to be present in contaminated soils at military training sites has not been extensively investigated. Thus, the Salmonella mutagenicity and Muta(TM)Mouse assays were employed as in vitro assays to examine the mutagenic activity of twelve explosive compounds, as well as three soil samples from Canadian Forces Base Petawawa. Salmonella analyses employed strains TA98 (frameshift mutations) and TA100 (base-pair substitution mutations), as well as the metabolically-enhanced YG1041 (TA98 background) and YG1042 (TA100 background), with and without exogenous metabolic activation (S9). For Salmonella analyses, the results indicate that ten of the explosive compounds were mutagenic, and consistently elicited direct-acting, base-pair substitution activity. All three soil samples were also observed to be mutagenic, eliciting direct-acting, frameshift activity. Mutagenic potencies were significantly higher on the metabolically-enhanced strains for all compounds and soil samples. For Muta(TM)Mouse analyses on FE1 cells, the results indicate that the majority of explosive compounds did not exhibit mutagenic activity. All three soil samples elicited significant positive responses (PET 1 and PET 3 without S9, and PET 2 with S9), and although there is some evidence of a concentration-related trend, the responses were weak. Correspondence of the mutagenic activity observed with the two assay systems, for both the explosive compounds and soil samples, was negligible. The differential response is likely due to differences in metabolic capacity between the two assay systems. Furthermore, it is likely that there are unidentified compounds present in these soil samples that are, at least in part, responsible for the observed mutagenic activity. Additional testing of other explosive compounds, as well as soil samples from other military training sites, using a variety of in vitro and in vivo assays, is warranted in order to reliably estimate mutagenic hazard and subsequently assess risk to human health.

Unlike municipal water supplies, provincial regulations do not require systematic testing of domestic well water, which may adversely impact local residents should contamination occur. Private wells are typically shallow relative to municipal wells, and thus, are particularly vulnerable to sources of surficial contamination if preferential recharge pathways such as natural fractures or faulty seals are present. In order to determine the relative importance of well seal integrity as a preferential pathway, a practical detection method was developed based on infiltrometry. This method successfully detected faulty well seals in a wide range of geological settings across Canada, including: Hobbema, Alberta; Lindsay, Ontario; and Chelsea, Québec. It was most successful in areas of minimal heterogeneity and where the surficial geology is composed of fine-grained sediments. The community of Chelsea (Québec) was also the primary study site to examine a range of factors affecting water quality including physical characteristics, faulty well seals, other anthropogenic activities and seasonality. Water samples were collected over a period of 14 months and analyzed for bacteria and major-ion chemistry. The results show that the consideration of physical features alone is not enough to predict vulnerability in the study area. Seasonal fluctuations in ionic concentrations (e.g. ionic strength, NO3-N and Cl-) and coliform bacteria are observed and result from disperse and rapid recharge events. Multivariate analysis techniques (e.g. principal components analysis and hierarchical cluster analysis) demonstrate that preferential recharge pathways and anthropogenic activities, such as domestic effluents affect the groundwater quality. The data and findings of this study were used to assist in the design of a probabilistic risk assessment model based on the Poisson distribution. This study demonstrates the complexity and the challenges related to bacterial contamination in drilled wells. In spite of these challenges, this analysis was useful as a baseline to assess the impact of anthropogenic activities, and may be used in future studies to assist municipalities in the evaluation and protection of groundwater supplies.

Microalgae are promising candidates for biofuel production, CO2 biomitigation, and production of a variety of value-added products. However, high production costs and large energy consumption have been a major concern hindering the commercialization of microalgal products and processes. In addition, biological contamination and oxygen stress are two of the major contributors to these challenges. The objective of this project was twofold: 1) developing a novel strategy for control of biological contamination to enable non-sterile cultivation of microalgae such as N. oleoabundans, and 2) developing advanced deoxygenation mechanisms to reduce oxygen accumulation in the culture. It was found that addition of appropriate amount of NaHCO3 could effectively inhibit the growth of protozoa while its inhibition on microalgae was much less and could be alleviated by increasing pH to an appropriate level. It was also found that adding 160 mM NaHCO3 in media or decreasing incident light intensity to 100 W/m2 would help alleviate the oxidative stress to cells at 400% of air saturation. The feasibility of contamination-free non-sterile cultivation of freshwater green alga N. oleoabundans was verified using long-term continuous cultivation in a 15-liter TPBR with non-sterile medium and aeration. Furthermore, localized oxygen removal using hydrophobic hollow membranes was found to effectively reduce dO2 and increase lipid accumulation. These results have the potential to be translated into low-cost cultivation of freshwater microalgae processes for production of value-added microalgal products. At a more fundamental level, the mechanisms of the inhibition of NaHCO3 on microalgae and protozoa were discussed. Efforts were also made to simulate the effects of incident light intensity on light distribution, cell growth kinetics, and lipid accumulation of N. oleoabundans under non- sterile cultivation conditions.

L’état Viable Non Cultivable (VNC) a été observé et décrit chez de nombreuses espèces bactériennes. Mais cet état métabolique a également été suggéré chez certaines cellules eucaryotes, et notamment chez les levures du vin comme Brettanomyces. L’état VNC chez cette levure a donc été étudié afin d’en déterminer les conditions d’entrée et de sortie, ainsi que les modifications morphologiques et métaboliques associées à cet état VNC. Une addition de sulfite (0,8 mg/L de SO2 moléculaire) induit un état VNC chez Brettanomyces, et une inactivation de ce sulfite par modification du pH du milieu permet une sortie de l’état VNC de la levure par un regain de cultivabilité. Dans les conditions VNC, la taille moyenne des cellules de Brettanomyces a été déterminée comme diminuée de 22% comparée à leur taille en condition contrôle. Ensuite, la capacité des cellules à produire des phénols volatils, éléments de contamination des vins, est conservée même lorsque les cellules sont en état Viable Non Cultivable. De plus, l’étude comparative des protéomes entre cellules de Brettanomyces témoin et cellules en état VNC montre une modification du métabolisme avec une diminution de la synthèse d’ATP compensée par une augmentation des protéines impliquées dans d’autres voies métaboliques de production d’énergie. Cette étude met donc en évidence pour la première fois l’existence de l’état VNC chez une espèce eucaryote et montre des points communs avec l’état VNC chez les cellules procaryotes. L’existence de cet état VNC chez Brettanomyces peut également engendrer des erreurs de détection. Un nouvel outil de détection par hybridation in situ et lecture par cytométrie en flux a donc été mis en place. Cette méthode permet ainsi la mise en évidence des cellules de Brettanomyces présentes en vin de façon efficace et rapide. / The viable but not culturable (VBNC) state has been studied in detail in bacteria. It has been suggested that the VBNC state also exists in eukaryote cells, such as wine yeasts, including Brettanomyces in particular. We investigated the VBNC state in this yeast, focusing on the conditions for entry and exit, and the morphological and metabolic modifications associated with this state. We added sulfite (0.8 mg.L-1 molecular SO2) to induce the VBNC state. Increasing the pH of the medium inactivated the sulfite, allowing the cells to exit from the VBNC state and to become culturable again. In these conditions, we found that Brettanomyces VBNC cells were smaller than culturable cells, and that spoilage by volatile phenols could persist during VBNC state. Furthermore, according to our proteome comparison, it seems that the blockade of ATP synthesis was compensated by an increase in energy-producing metabolism pathway. This study provides the first insight into the VBNC state in eukaryote cells, showing common trend to the VBNC state of prokaryotic cells. The existence of VBNC state in Brettanomyces cells can also provoke errors of detection. A new tool of detection by fluorescence in situ hybridization and reading by flow cyometry was thus set up. This method allows the revealing of Brettanomyces cells presence in wine in an efficient and fast way.

The practices of solid waste management (SWM) and solid waste disposal (SWD) in Kano metropolis, Nigeria, were examined. The water quality of groundwater sources in the areas adjacent to the SWD sites was monitored in order to evaluate interactions and assess the possibility of groundwater contamination as a result of percolation of the leachates generated in the SWD sites. An integrated approach to the field investigation was employed in the study. This included an extensive desk study; a field survey of all existing SWD sites in the area; leachate and groundwater sampling; and laboratory-based experimental and instrumental analyses. The locations of the SWD sites relative to inhabited areas were examined, and eight sites and their environs were selected for leachate and groundwater sampling and quality assessments in May 2009 and May 2010. It was observed that SWM activities in Kano metropolis are unsystematic and pose a significant risk to both public health and environmental quality, especially in relation to local groundwater sources. It was also found that the leachates produced in the sampled sites contained significant concentrations of a wide range of contaminants; including nitrates, total alkalinity, total dissolved solids, chlorides and sulphates. The leachates were also observed to be in the methanogenic phase of biochemical degradation and were shown to have similar characteristics to other leachates from mature SWD sites in different parts of the world. Similarly, the physico-chemical characteristics of the groundwater samples around the selected SWD sites indicated high concentrations of nitrates, chlorides, total dissolved solids, total alkalinity, turbidity, iron and manganese, often above the WHO thresholds for acceptable drinking water quality. It is, therefore, concluded that the shallow groundwater sources analysed have been contaminated, due largely to improper SWM practice. This, in turn, affects not only the health and well-being of the local population, but also impedes developmental efforts and obstructs prosperity. Accordingly, some strategies for pollution prevention and control were developed for Kano metropolis, although they are also applicable to other urban areas with similar characteristics. These strategies, which are largely categorised as resource-focused, source-focused or remedial measures, can be achieved through: (1) identification and mapping of pollution sources; (2) establishment of databases and information management system; (3) vulnerability mapping; (4) establishment of functional monitoring and evaluation system; (5) promotion of public awareness and participation; (6) establishment of protection zones; and (7) the integration of pollution prevention and control strategy into urban planning, development and management of municipal services.

The study of acid rock and mine (ARD and AMD) environments mainly focused on the mineralogical and microbiological conditions and responses of such systems. Most of the research that involved some organic viewpoint was related to the amelioration of the environmental conditions, sometimes with contradictory results. How organic matter (OM) participates and which organic fractions are involved in ARD and AMD processes remain unclear. In this work we have applied organic geochemistry tools combined with mineralogical ad molecular microbiology techniques to study of ARD and AMD environments. The main objectives were to identify and characterise the natural sources of OM occurring both at ARD and AMD sites, and to determine whether the OM sources identified are involved in the generation or amelioration of AMD/ARD. This study shows that multiple OM sources occur naturally in acid drainage environments, included plant derived material and mature, petroleum-derived hydrocarbons, originating from the source rocks, apparently have not directly influence on the processes. This suggests that the generation of ARD and AMD is a completely chemoautotrophic process. Particle size of the iron phases present at ARD sites seems to be involved in the iron bioavailability. The presence of goethite in ARD/AMD systems may have a relationship with the presence of OM. Stimulation of ARD sediments using plant derived OM, abundantly present in and around ARD and AMD ponds systems does not result in the neutralisation of ARD or AMD. This suggests that plant material is not used by Fe(III)-reducing bacteria. However, it fuels fermentation processes and it is likely that fermentation products such as acetate, detected in microcosms and in situ, could limit Fe(III)-reduction. In contrast, the stimulation of ARD sediments using manure (particularly sheep manure) raises the pH up to near neutral conditions. Although it remains unclear which OM fraction from the manure is actively involved in the neutralisation of ARD; these results suggest that manure may make an interesting and non-expensive electron donor in AMD/ARD treatments.

This dissertation focuses on the chemistry, detection, and control of metals and metal contaminants during manufacturing of integrated circuits (ICs) on silicon wafers. Chapter 1 begins with an overview of IC manufacturing, including discussion of the common aqueous cleaning solutions, metallization processes, and analytical techniques that will be investigated in subsequent chapters. Chapter 2 covers initial investigations into the chemistry of the SC2 clean - a mixture of HCl, H2O2, and DI water - especially on the behavior of H2O2 in this solution and the impact of HCl concentration on metal removal from particle addition to silicon oxide surfaces. Chapter 3 includes a more generalized investigation of the chemistry of metal ions in solution and how they react with the silicon oxide surfaces they are brought into contact with, concluding with illumination of the fundamental chemical principles that govern their behavior. Chapter 4 shows how metal contaminants behave on silicon wafers when subjected to the high temperature (≥ 800 °C) thermal cycles that are encountered in IC manufacturing. It demonstrates that knowledge of some fundamental thermodynamic properties of the metals allow accurate prediction of what will happen to a metal during these processes. Chapter 5 covers a very different but related aspect of metal contamination control, which is the effectiveness of metal diffusion barriers (e.g. Ru) in holding a metal of interest, (e.g. Cu), where it is wanted while preventing it from migrating to places where it is not wanted on the silicon wafer. Chapter 6 concludes with an overview of the general chemical principles that have been found to govern the behavior of metals during IC manufacturing processes.

O objetivo desta tese foi o desenvolvimento de um equipamento compacto para o tratamento de águas subterrâneas contaminadas por BTEX e TPH em postos de combustíveis. Esta questão ambiental é uma preocupação mundial devido ao nível de contaminação e a quantidade de vazamentos existentes, toxicidade dos poluentes e a necessidade de uso de aquíferos para consumo humano. O equipamento é composto por unidades que contemplam as seguintes etapas: (a) sucção e volatilização de compostos orgânicos voláteis; (b) injeção de ar (“air sparging”) para remoção de substâncias orgânicas voláteis; e (c) filtro de adsorção com recheio composto por mistura de 50% de carvão ativado e 50% de cinza de casca de arroz para a remoção de TPH. A parte experimental envolveu a caracterização de águas subterrâneas contaminadas e estudos em escala piloto e real. Os resultados obtidos demostraram que o equipamento de remediação desenvolvido é altamente eficiente para o tratamento de águas subterrâneas contaminadas. Com um tempo de detenção de 8 horas, obtiveram-se decréscimos superiores a 96% de BTEX e TPH. Nesta situação, a água contaminada tratada alcança valores que atendem aos critérios de lançamento estabelecidos pelas legislação nacional vigente. / This study describes the development of a compact device to treat groundwater contaminated with BTEX and TPH in gas stations. This environmental issue raises concerns worldwide, due to the level of contamination, the high occurrence of leaks, the toxicity of contaminants, and the importance of aquifers for human consumption. The equipment was formed by: a) a suction and treatment stage using vacuum and aeration with injectors (to replace the suction system based on a conventional vacuum pump and the air stripping and/or air sparging system); b) small-scale surface aerators (to replace the air stripping and/or air sparging system); c) an adsorption filter using a mixture of activated carbon (50%) and rice husk ash (50%) (to replace the activated carbon system). The experiment was conducted in four stages: a) characterization of groundwaters; b) presentation of the adsorbents used in the filter; c) pilot test (under controlled conditions to measure the efficiency to remove BTEX and TPH); and d) the full-scale tests (observation and confirmation of equipment efficiency). The results show that the remediation equipment developed is highly efficient to treat contaminated groundwater. An 8-h retention time afforded to reduce BTEX and TPH levels by over 96%. In this scenario, the treated water parameters meet the current legal requirements for discharge.

Orientador: Brenda Paula Figueiredo de Almeida Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T14:01:31Z (GMT). No. of bitstreams: 1 Chiesa_WandersonMiguelMaia_D.pdf: 2308331 bytes, checksum: 52ef248e0f498c63a519acd9b0b14e9a (MD5) Previous issue date: 2011 / Resumo: Conteúdos dos canais radiculares podem ficar aderidos às limas endodônticas durante o preparo químico-mecânico, tais como endotoxinas, com grande potencial de desencadear resposta inflamatória. Instrumentos endodônticos são frequentemente reutilizados, existindo preocupação sobre a neutralização daqueles conteúdos pelos métodos de esterilização empregados em consultórios odontológicos. Os objetivos deste estudo foram: avaliar os efeitos de esterilização por estufa de calor seco ou autoclave, na detecção de DNA bacteriano e níveis de endotoxinas de limas endodônticas contaminadas in vivo, verificando correlações entre as espécies detectadas; investigar a produção de IL-1ß por macrófagos murinos estimulados in vitro por amostras coletadas de hastes metálicas contaminadas de limas endodônticas e esterilizadas por estufa de calor seco ou autoclave. Oitenta limas endodônticas manuais número 15 de aço inoxidável ficaram estéreis e apirogênicas, após esterilização pelo calor seco a 200ºC/4h. Vinte limas tiveram seus cabos removidos e as hastes metálicas destinadas ao Grupo I (Controle negativo), em frascos apirogênicos. Vinte pacientes apresentando necrose da polpa dental, lesão periapical e sem dor espontânea foram incluídos nesta pesquisa. Cavidades de acesso foram assepticamente preparadas e três limas apirogênicas sucessivamente introduzidas e removidas até o comprimento de trabalho de cada canal. Depois do uso, os cabos foram removidos, as hastes metálicas inseridas em frascos estéreis e apirogênicos e os outros grupos foram divididos (n=20): Grupo II (Controle positivo) - amostras sem esterilização; Group III - esterilização pela estufa de calor seco (170ºC/1h); Grupo IV - amostras autoclavadas. A técnica PCR (16S rDNA) foi usada para detectar DNA bacteriano, um teste turbidimétrico do Lisado dos Amebócitos de Limulus (LAL) foi usado para mensurar os níveis de endotoxinas e o método ELISA calculou as quantidades de IL-1ß liberadas por macrófagos murinos estimulados pelos conteúdos das limas contaminadas e esterilizadas. Prevotella nigrescens, Porphyromonas endodontalis e Treponema socranskii foram as bactérias-alvo mais frequentemente detectadas, a partir das amostras contaminadas e não esterilizadas. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tanerella forsythia e Prevotella tannerae não foram identificadas. Correlação positiva estatisticamente significante (p<0.05) foi encontrada entre Porphyromonas endodontalis e Treponema denticola, e desta com Treponema socranskii. Depois de esterilização pela estufa de calor seco ou autoclave, o método PCR não detectou bactérias. O teste turbidimétrico indicou a mediana de 1,070 UE/mL, 0,875 UE/mL e 0,251 EU/mL, no grupo sem esterilização, esterilizado pela estufa de calor seco e autoclavado, respectivamente. Macrófagos estimulados pelas amostras das limas contaminadas e autoclavadas liberaram IL-1ß (mediana de 55,39 pg/mL). Conclusão: DNA bacteriano não foi detectado depois da esterilização pela estufa de calor seco ou autoclave, mas estes métodos não foram capazes de eliminar endotoxinas de limas endodônticas contaminadas e não foram encontradas diferenças estatisticamente significantes entre os dois métodos de esterilização empregados (p>0.05). Correlações positivas significantes foram detectadas entre micro-organismos colhidos de limas endodônticas contaminadas. Amostras autoclavadas estimularam a liberação de IL-1ß por macrófagos, mas não foram detectados níveis mensuráveis desta citocina depois da estimulação pelas amostras esterilizadas por calor seco / Abstract: Contents from root canal can be attached on endodontic files during chemomecanical preparation, such as endotoxin, with great potential to trigger inflammation. Endodontic instruments are often reused, and there is a concern about the neutralization of those contents by sterilization methods employed in dental offices. The objectives of this study were: to evaluate the effect of sterilization by dry heat oven or autoclave, in the bacterial DNA detection and endotoxin levels from in vivo contaminated endodontic files, verifying correlations between detected species; to investigate IL-1ß production by murine macrophage stimulated in vitro by samples from contaminated metal shafts of endodontic files and sterilized by dry heat oven or autoclave. Eighty size 15 stainless steel hand files were sterile and apyrogenic, after dry heat sterilization at 200ºC/4h. Twenty files had their handles cut off and metal shafts destined to the Group I (Negative control), in apyrogenic vials. Twenty patients presenting dental pulp necrosis, periapical lesion and without spontaneous pain were included in this research. Access cavities were aseptically prepared and three apyrogenic files were successively introduced and removed at the working length of each canal. After use, handles were cut off, metal shafts inserted in apyrogenic vials and the other groups were divided (n=20): Group II (Positive control) - samples with no sterilization; Group III - sterilization by dry heat oven (170ºC/1h); Group IV- autoclaved samples. PCR technique (16S rDNA) was used to detect bacterial DNA, Limulus Amebocyte Lysate (LAL) turbidimetric test measured endotoxin levels and ELISA method calculated amounts of IL-1ß released by murine macrophage stimulated by contents from the contaminated and sterilized files. Prevotella nigrescens, Porphyromonas endodontalis and Treponema socranskii were the most frequently detected target bacteria, from contaminated and non sterilized samples. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tanerella forsythia and Prevotella tannerae were not identified. Statistically significant positive correlation (p<0.05) was found between Porphyromonas endodontalis and Treponema denticola, and between Treponema denticola and Treponema socranskii. After sterilization by dry heat oven or autoclave, PCR method detected no bacteria. Turbidimetric test indicated median of 1.070 EU/mL, 0.875 EU/mL and 0.251 EU/mL, in the group without sterilization, sterilized by dry heat oven and autoclaved, respectively. Macrophage stimulated by samples from contaminated and autoclaved files released IL-1ß (median of 55.39 pg/mL). Conclusion: no bacterial DNA was detected (PCR technique - 16S rDNA) after sterilization by dry heat oven or autoclave, but these methods were not able to eliminate endotoxin from contaminated endodontic files and no statistically significant differences were found between the two methods of sterilization employed (p>0.05). Significant positive correlations were detected between microorganisms collected from contaminated endodontic files. Autoclaved samples stimulated IL- 1ß releasing by macrophage, but no measurable levels of this cytokine were detected after stimulation by dry heat sterilized samples / Doutorado / Endodontia / Doutor em Clínica Odontológica

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-04-20T14:35:10Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ribas tese vf.pdf: 2036236 bytes, checksum: 4d1f446720dbedcab34a1394932ee78f (MD5) / Made available in DSpace on 2016-04-20T14:35:10Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ribas tese vf.pdf: 2036236 bytes, checksum: 4d1f446720dbedcab34a1394932ee78f (MD5) Previous issue date: 2015-03-06 / FACEPE / O termo biocombustível refere-se aos biocombustíveis sólidos, líquidos ou gasosos que são produzidos predominantemente por matérias-primas. Atualmente, dois tipos de combustíveis são utilizados para o transporte a nível global, o bioetanol e o biodiesel. Destacando-se o bioetanol, sendo este o mais consumido mundialmente. A produção desse biocombustível a partir da cana-de-açúcar no Brasil e milho nos Estados Unidos apresenta um mercado maduro com os dois países liderando a produção mundial. Contudo as destilarias de todo mundo que produzem etanol a partir dessas matérias primas ou outros cereais tem presenciado diminuição no rendimento industrial, e uma das causas é a presença de contaminantes bacterianos. Os episódios de contaminação são normalmente causados por bactérias láticas (LAB), devido à sua capacidade de adaptação às condições adversas impostas pelo processo industrial. Além disso, o aumento da população de espécies de leveduras contaminantes, podem também contribuir para a redução da produção de etanol. O presente trabalho avaliou a possível relação ecológica entre a levedura comercialmente utilizada para o processo fermentativo das destilarias de etanol a S. cerevisiae e dois microrganismos freqüentemente encontrados no processo: a levedura Dekkera bruxellensis e a bactéria Lactobacillus vini. Os resultados mostraram que o elevado teor de etanol no meio produzido por S. cerevisiae, pode controlar a população de bactérias, enquanto que a diminuição deste metabolito causada pelo aumento de contagem de células de D. bruxellensis poderia favorecer o crescimento bacteriano. Além disso, o elevado número de células bacterianas promoveu o aumento na produção de ácido orgânico que reduz o crescimento de levedura. No entanto, este fenômeno pareceu dependente do pH do meio. Por fim, foi realizado um estudo acerca do metabolismo de carboidratos de L. vini em meio sintético similar ao Manga Rosa Shape, com o objetivo de analisar a velocidade específica de L.vini e a sua biomassa final, tendo sido demonstrado uma alta biomassa quando celobiose, glicose, frutose e sacarose foram utilizados em relação a lactose e maltose, quando citrato de amônio estava presente no meio. Contudo a velocidade específica de crescimento de L.vini e sua biomassa variaram para os diferentes carboidratos com a mudança de citrato de amônio para sulfato de amônio, nitrato de sódio ou glutamato. A velocidade específica de crescimento e a biomassa de L.vini também foram analisadas em caldo e melaço da cana de açúcar com Brix 12, adicionados ou não de suplementos nutricionais como peptona, extrato de levedura, extrato de carne, citrato de amônia, Tween 80 e vitaminas, assim como com lisado celular de S.cerevisiae, interessantemente L.vini cresceu em caldo porém não em melaço quando adicionados do lisado de S.cerevisiae. Dessa forma, estamos apresentando um dos principais aspectos ecológicos da relação entre leveduras e bactérias que tem um enorme significado para o processo de produção de etanol. / The biofuel term refers to solid, liquid, or gaseous biofuels that are made predominantly of raw materials. Currently, two fuels are used to transport the global level, bioethanol and biodiesel. Highlighting bioethanol, which is the most consumed worldwide. The production of this biofuel from sugar cane in Brazil and corn in the United States has a mature market with more advanced technology. However distilleries worldwide that produce ethanol from these raw materials or other cereals has witnessed decline in industrial output, and one reason is the presence of bacterial contaminants. The episodes of contamination are normally caused by Lactic Acid Bacteria (LAB) due to their adaptability to the rough conditions imposed by the industrial process. Furthermore, the increase in the population of contaminating yeast species may also contribute to the reduction of ethanol production. This study evaluated the possible ecological relationship between the yeast commercially used for the fermentation of ethanol distilleries S. cerevisiae and two microorganisms frequently found in the process: the yeast Dekkera bruxellensis and the bacterium Lactobacillus vini. The results showed that high ethanol content in the medium produced by S. cerevisiae can control bacterial population, while the decrease of this metabolite caused by the raising of D. bruxellensis cell count could stimulate bacterial growth. Furthermore, the high number of bacterial cell promoted the increase in organic acid production that reduces yeast growth. However, this phenomenon seemed dependent on the medium pH. Finally, a study was conducted on the L.vini carbohydrate metabolism in synthetic medium, in order to analyze the specific growth rate and biomass of L.vini, it has been demonstrated high biomass while cellobiose, glucose, fructose and sucrose were used in connection with the lactose and maltose, while ammonium citrate was present in the medium. However, the specific growth rate and biomass of L.vini varied for different carbohydrates with a change in ammonium citrate to ammonium sulfate, sodium nitrate or glutamate. The specific growth rate and biomass of L.vini were also analyzed in broth and molasses from sugar cane with Brix 12, with or without nutritional supplements as peptone, yeast extract, meat extract, ammonium citrate, Tween 80 and vitamins, as well as with cell lysate of S. cerevisiae, interestingly L.vini grown in broth but not in molasses when added lysate of S. cerevisiae. Thus, we are presenting one of the major ecological aspects of the relationship between yeasts and bacteria that has an enormous significance to ethanol production process.