Submitted by Kelson Anthony de Menezes (kelson@ucb.br) on 2016-11-23T11:53:28Z No. of bitstreams: 1 OhanaYonaradeAssisCostaDissertacaoparcial2015.pdf: 2702312 bytes, checksum: 31ec065175a2d2c39c8a0c2121900693 (MD5) / Made available in DSpace on 2016-11-23T11:53:28Z (GMT). No. of bitstreams: 1 OhanaYonaradeAssisCostaDissertacaoparcial2015.pdf: 2702312 bytes, checksum: 31ec065175a2d2c39c8a0c2121900693 (MD5) Previous issue date: 2014-03-31 / The interest in biofuels started in the 2000s, due to a greater concern with the production of cleaner and renewable energy sources needed to decrease global dependency on fossil fuels. Brazil is the largest producer of sugar cane and the second largest producer of ethanol. Although the process is already well established, microbial contamination can be an obstacle, resulting in decreased productivity. The aim of this work was to study the microbial diversity of contaminants in six stages of ethanol production process using classical microbiology techniques and cultureindependent techniques. Triplicate samples from different stages of ethanol production were collected: sugarcane juice, mixed juice, clarified juice, evaporated juice, must and wine. Each sample was diluted and plated on four culture media: PCA, MRS and YPD CZAPEK. The colonies were counted, isolated and stored in glycerol at -80?? C. DNA extraction of samples was done, and the DNA of each one of the replicates of each sample was used for pyrosequencing of Bacteria and Archaea 16S rRNA genes, and Fungi ITS gene. The sequences generated were subjected to bioinformatics analysis using a specific database to the genes. It were isolated and stored in 64 bacteria, 30 yeasts, 20 filamentous fungi, which were identified by Sanger sequencing. The pyrosequecing showed 322 genera for the domain Bacteria, 21 genera for the domain Archaea and 184 genera for the domain Fungi. Among the predominant genera of bacteria in samples of sugarcane juice, mixed juice, clarified juice, evaporated juice and must are Leuconostoc, unclassified Enterobacteriales and unclassified Actinomycetales, while in the wine sample, the predominant genus was Lactobacillus, one of the major contaminants of ethanol production. For the domain Fungi, only sequenced in the sugarcane juice and mixed juice, the predominant groups were Lachancea, unclassified Hypocreales and unclassified Sordariomycetes. For the domain Archaea, also sequenced only in the sugarcane juice and mixed juice, the predominant group was unclassified Soil Crenarchaeotic group. Rarefaction curves showed that the samples of sugarcane juice, mixed juice and clarified juice did not have diversity at the genus level covered, and for sugarcane juice and mixed juice samples, the diversity was not covered in any of the domains, showing that further studies involving the diversity of these samples are needed. / O interesse na produ????o de biocombust??veis se iniciou na d??cada de 2000, devido a uma maior preocupa????o com a produ????o de fontes de energia mais limpas e renov??veis, necess??rias para diminui????o da presente depend??ncia mundial dos combust??veis f??sseis. O Brasil ?? o maior produtor mundial de cana-de-a????car e o segundo produtor mundial de etanol. Embora o processo de produ????o do etanol esteja bem estabelecido, a contamina????o microbiana pode ser um obst??culo, gerando diminui????o da produtividade. O objetivo desse trabalho foi estudar a diversidade microbiana de contaminantes em seis etapas do processo de produ????o de etanol utilizando t??cnicas de dependentes e independentes de cultivo. Amostras triplicadas de diferentes est??gios da produ????o de etanol foram coletadas: caldo da cana crua, caldo misto, caldo clarificado, caldo evaporado, mosto e vinho. Cada amostra foi dilu??da e semeada em quatro meios de cultura: PCA, MRS, CZAPEK e YPD. As col??nias foram contadas, isoladas e armazenadas em glicerol a -80??C. Foi feita a extra????o de DNA das amostras, e o DNA das replicatas de cada amostra foi utilizado para o pirosequenciamento dos genes do RNAr 16S dos dom??nios Bacteria e Archaea e da regi??o ITS do reino Fungi. As sequ??ncias geradas foram submetidas a an??lise bioinform??tica utilizando-se banco de dados espec??ficos para os genes em quest??o. Foram isolados, armazenados e identificados por sequenciamento de Sanger 64 bact??rias, 30 leveduras e 18 fungos filamentosos. O pirosequenciamento demonstrou a presen??a de 322 g??neros/grupos n??o classificados para o dom??nio Bacteria, 21 g??neros/grupos n??o classificados para o dom??nio Archaea e 184 para o reino Fungi, no total. Entre os g??neros de bact??rias predominantes nas amostras de caldo da cana crua, caldo misto, caldo clarificado, caldo evaporado e mosto est??o Leuconostoc, Enterobacteriales n??o classificados e Actinomycetales n??o classificados, enquanto que na amostra de vinho, o g??nero predominante ?? Lactobacillus, um dos maiores contaminantes da produ????o de etanol. Para o reino Fungi, sequenciado apenas no caldo da cana crua e no caldo misto, foram predominantes os grupos Lachancea, Hypocreales n??o classificados e Sordariomycetes n??o classificados. Para o dom??nio Archaea, tamb??m sequenciado apenas no caldo da cana crua e no caldo misto, predominaram sequ??ncias n??o classificadas do Soil Crenarchaeotic Group. As curvas de rarefa????o mostraram que as amostras de caldo da cana crua, caldo misto, caldo clarificado n??o tiveram sua diversidade coberta em n??vel de g??nero, sendo que para as amostras de caldo da cana crua e caldo misto a diversidade n??o foi coberta em nenhum dos dom??nios, de modo que s??o necess??rios mais estudos envolvendo a diversidade dessas amostras.