Análise proteômica da levedura Saccharomyces cerevisiae CAT-1 cultivada em diferentes concentrações de sacarose

• Autor(a) principal: Azarias, Gabriela de Sá [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/124409
• topic: Proteômica; Levedos; Etanol; Fermentação; Microbiologia industrial; Ethanol

Bacause of the national and international increasing demand for fuel ethanol, the alcohol industry needs more studies to benefit productivity without exacerbated increased investment. Therefore, it is necessary biochemical and physiological knowledge of the microorganisms and optimization of the medium and fermentation conditions. The proteomic analysis proposed in this work is a key tool in the elucidation of the changes suffered by the microorganism when exposed to adversity as, for example, aeration difficulty, low pH maintenance and sugar content of the mash and variations in molasses according to the harvest, recurrent situations in industrial fermentation processes. So, the aim of this study was to investigate the biochemical changes suffered by Saccharomyces cerevisiae CAT-1 grown by 30% (very high gravity fermentation) and 14% (high gravity fermentation) sucrose concentration. The analysis were performed by two-dimensional electrophoresis followed by mass spectrometry (MALDI-TOF/TOF). The results showed the presence of 22 differential protein spots between the two conditions with regard to quantitative analysis, qualitative and statistics analysis. Four of these spots were sequenced and correspond to GRX1p, Rtc3p, ENO2p and ADH1p. Additionally, the invertase activity was analyzed for understanding the catabolite repression and the enzyme activity reached its peak in 10 h in cultures containing 30% sucrose (13.68 ± 2,26U.ml-1). The ethanol yield and cell viability analysis showed that cultures containing 30% sucrose show advantageous results when compared to cultures containing 14% sucrose, once these cultures provided an ethanol yield of 15.99% and 99.2% viable cells at the end of each fermentation, very close to the theoretical values expected for an industrial process. Biomass and reducing sugars were also quantified.