Avaliação do potencial de fermentação alcoólica por Brettanomyces bruxellensis em diferentes fontes de carbono

• Ano de defesa: 2019
• Autor(a) principal: Kaehler, Cristina
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Positivo; Brasil; Pós-Graduação; Programa de Pós-Graduação em Biotecnologia Industrial; UP
• Palavras-chave em Português: Biotecnologia; Álcool; Leveduras; Fermentação; Sacarose; Frutose; Glicose; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2289

Advances in the field of biotechnology have been essential for the evolution of the ethanol industry in Brazil. Brettanomyces bruxellensis yeast is commonly found in commercial fermentation environments. This yeast can ferment a variety of carbon sources, but at varying rates. Its unique aroma profile makes it interesting for beer production, in addition to its low pH tolerance and ability to produce high concentrations of ethanol, characteristics of interest to the brewing and bioethanol industry. The objective of this work was to evaluate the fermentative potential of Brettanomyces bruxellensis, isolated from a brewery in Brussels - Belgium, in the presence of different sugars. Initially, growth analysis was performed on Yeast Nitrogen Base medium supplemented with xylose, glucose, sucrose, fructose and lactose. Plates containing calcium carbonate medium were prepared for the evaluation of acid production. Then, the alcohol tolerance test was performed in the presence of ethanol at concentrations of 0%, 4%, 6%, 8%, 10% and 12% (v/v). In addition, yeast growth in YPD medium with pH ranges between 2 - 8 was also evaluated. Finally, the alcoholic fermentation in sucrose, fructose and glucose was evaluated. The yeast used was not able to consume xylose and lactose, showing growth only in media supplemented with sucrose, fructose and glucose. Alcoholic fermentation was also observed in the presence of these sugars, with an alcoholic content of 1,33% for sucrose, 1,22% for fructose and 1,21% for glucose. The indication of acid production by yeast was observed in the tests in calcium carbonate medium, due to the formation of transparent halos around the colonies. In addition, the yeast showed growth in medium containing 12% ethanol and at pH in the range 3 - 8. It is concluded that the Brettanomyces bruxellensis strain has potential to be used in biotechnological processes, mainly due to the tolerance to high ethanol concentration and performance in a wide pH range.