Diversidade microbiana na produ????o de etanol utilizando t??cnicas tradicionais e biologia molecular

• Ano de defesa: 2014
• Autor(a) principal: Costa, Ohana Yonara de Assis
• Orientador(a): Quirino, Betania Ferraz
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Cat??lica de Bras??lia
• Programa de Pós-Graduação: Programa Strictu Sensu em Ci??ncias Gen??micas e Biotecnologia
• Departamento: Escola de Sa??de e Medicina
• País: Brasil
• Palavras-chave em Português: Biotecnologia; Biologia molecular; Energia da biomassa; ??lcool; Contamina????o microbiana
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::GENETICA
• Resumo em Inglês: 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.
• Link de acesso: https://bdtd.ucb.br:8443/jspui/handle/tede/1977

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.