Influência da glucose, etanol e dióxido de enxofre no crescimento de bactérias do ácido lático

• Author(s): Ramos, Ana Patrícia Pedro
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.5/5682
• Origin: Repositório da UTL
• Subject(s): wine; lactic acid bacteria; glucose; ethanol; sulphur dioxide; response surface method
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Malfeito Ferreira, Manuel
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto

The aim of this study was to evaluate the effect of various factors on the inhibition of lactic acid bacteria (LAB) related to wine. The bacteria chosen were Lactobacillus plantarum, Lactobacillus mali, Lactobacillus hilgardii, Leuconostoc mesenteroides and Oenococcus oeni. The choice fell on their importance in the wine world both as agents of malolactic fermentation as for production of microbiological changes in wine. In the first perspective growths of LAB were performed in wine. However, the absence of growth led to carry out tests on synthetic medium MRS. In this context, the work involved the construction of a central composite design by response surface method using three factors: glucose (2 - 10 g/L), ethanol (10 - 15% (v/v)) and carbon dioxide sulfur (0-40 mg/L), chosen because of its importance in wine. The results showed that ethanol was dominant as an inhibitor agent, above 14%, and with a slow growth of 12.5% as opposed to sulfur dioxide, which, in the tested concentrations did not manifest itself as an inhibitor agent. Glucose did not show a stimulating effect on growth which contradicted inhibition by ethanol.