Produção de etanol por sacarificação e fermentação simultâneas do bagaço de cana-de-açúcar utilizando leveduras termotolerantes

• Ano de defesa: 2011
• Autor(a) principal: Souza, Carlos Joulbert Alves de
• Orientador(a): Fietto, Luciano Gomes
• Banca de defesa: Queiroz, José Humberto de , Guimarães, Valéria Monteze
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Bioquímica Agrícola
• Departamento: Bioquímica e Biologia molecular de plantas; Bioquímica e Biologia molecular animal
• País: BR
• Palavras-chave em Português: Etanol; Bagaço de cana-de-açúcar; Leveduras
• Palavras-chave em Inglês: Ethanol; Sugarcane bagasse; Yeasts
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::BIOLOGIA MOLECULAR
• Link de acesso: http://locus.ufv.br/handle/123456789/2431

The aim of this work was to compare the ethanol production between LBM-1 and Kluyveromyces marxianus UFV-3. The assay of thermotolerance was performed to characterize the strains as the capacity to grow at different temperatures. It was found that both grew at temperatures of 28, 37 and 42oC. Only K. marxianus UFV-3 grew at 45oC. It was, also, evaluated the fermentation of sugar cane bagasse, which was submitted to Acid/Alkali pretreatments, in processes of saccharification and fermentation simultaneous (SSF) at 37 and 42oC, analyzing even different times of prehydrolysis of the biomass at 37, 42 and 50oC. The yields of ethanol production were similar at 37 and 42oC for both strains. It was found that the ethanol yield was higher when the bagasse was initially submitted to a hydrolysis at 50oC for 72 hours. Thereafter was analyzed the relation between fermentation and number of cycles and it was determined the maximum number of cycles performed without loss of ethanol yield. The ethanol yield for K. marxianus UFV-3 decreases at cicle fourth and then, remained constant. The S. cerevisiae LBM-1 income increased during the cycle. These results suggest the use of two strains in the production of cellulosic ethanol by processes of SSF because they have ethanol yields statistically identical. However the number of fermentation cycles without loss of yield by strain K. marxinaus UFV-3 was lower than that LBM-1, indicating that this is more suited to the production process by industries in the fed batch production of ethanol.