Publicação
Factors affecting the production of 4-ethylphenol by the yeast Dekkera bruxellensis in enological conditions
| Resumo: | The conversion of p-coumaric acid into 4-ethylphenol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in synthetic media. The production of 4-ethylphenol occurred roughly between mid-exponential growth phase and the beginning of the stationary phase. This behaviour was observed when glucose was the only energy and carbon source, the conversion rate being close to 90%. Ethanol, as the single energy source, yielded conversion rates close to 80% while in the presence of trehalose and acetic acid conversion rates lower than 10% were obtained. The production of 4-ethylphenol was not observed when the cells were maintained in buffer solution without carbon and energy sources. The precursor of 4-ethylphenol, p-coumaric acid, was not utilized as energy and carbon source. Furthermore, it was shown that 4-vinylphenol may be used as a precursor of 4-ethylphenol in the absence of pcoumaric acid. Growth and 4-ethylphenol production were inhibited by increasing concentrations of ethanol, being fully prevented at 13% (v/v) ethanol. The cultivation of strain ISA 1791 in mixed culture with Saccharomyces cerevisiae, in synthetic medium, showed that the cell numbers of D. bruxellensis increased from 104 cfu/ml to 5 109 cfu/ml. Laboratory microvinifications of white and red juices inoculated with as low as 10 cfu/ml of D. bruxellensis and 107 cells/ml of S. cerevisiae showed growth of D. bruxellensis to levels of about 5 108 cfu/ml. In addition, 4-ethylphenol production by D. bruxellensis was observed only after complete fermentation of the grape juices |
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| Autores principais: | Malfeito-Ferreira, Manuel |
| Outros Autores: | Loureiro, Virgilio; Dias, L.; Pereira-da-Silva, S.; Tavares, M. |
| Assunto: | dekkera bruxellensis wine grape juice 4-ethylphenol p-coumaric acid ethanol |
| Ano: | 2003 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The conversion of p-coumaric acid into 4-ethylphenol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in synthetic media. The production of 4-ethylphenol occurred roughly between mid-exponential growth phase and the beginning of the stationary phase. This behaviour was observed when glucose was the only energy and carbon source, the conversion rate being close to 90%. Ethanol, as the single energy source, yielded conversion rates close to 80% while in the presence of trehalose and acetic acid conversion rates lower than 10% were obtained. The production of 4-ethylphenol was not observed when the cells were maintained in buffer solution without carbon and energy sources. The precursor of 4-ethylphenol, p-coumaric acid, was not utilized as energy and carbon source. Furthermore, it was shown that 4-vinylphenol may be used as a precursor of 4-ethylphenol in the absence of pcoumaric acid. Growth and 4-ethylphenol production were inhibited by increasing concentrations of ethanol, being fully prevented at 13% (v/v) ethanol. The cultivation of strain ISA 1791 in mixed culture with Saccharomyces cerevisiae, in synthetic medium, showed that the cell numbers of D. bruxellensis increased from 104 cfu/ml to 5 109 cfu/ml. Laboratory microvinifications of white and red juices inoculated with as low as 10 cfu/ml of D. bruxellensis and 107 cells/ml of S. cerevisiae showed growth of D. bruxellensis to levels of about 5 108 cfu/ml. In addition, 4-ethylphenol production by D. bruxellensis was observed only after complete fermentation of the grape juices |
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