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| Author(s): |
Denise Amaral Duarte Aranha
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2002-04-12 |
| Examining board members: |
Luiz Carlos Basso;
André Ricardo Alcarde;
Mario Lucio Lopes
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| Advisor: | Luiz Carlos Basso |
| Abstract | |
The aim of this work was to study physiological and biochemical effects caused by aluminum (Al) in two strains of Saccharomyces cerevisiae: baker's yeast Fleischmann and strain PE-2. For such, was tried to simulate, so much as possible, the physiological conditions of the industrial process. Four experiments were performed: using semi-synthetic and cane juice containing 200g of total reducing sugar per liter at pH 4.0 and 5.0. Aluminum was added in the form of AlCl3.6H2O in the following proportions: 0 (control), 50 mg/L and 100 mg/L . The experiments were performed with cell reuse and the following parameters were analysed: ethanol production, glicerol production and residual sugars, growth of the yeast, yeast viability, bacterial contamination, trehalose and glycogen content and accumulation of aluminum in the yeast cells. It was concluded that toxic levels of aluminum could be present in industrial substrates, since toxic effects were verified for both strains. The strain PE-2 showed to be more tolerant to aluminum when compared to baker's yeast. (AU) | |