Capacity strains of Saccharomyces cerevisiae to inhibit the activity Brettanomyces custersianus during the winemaking

Leveduras do gênero Dekkera/Brettanomyces causam sérios problemas ao vinho, afetando as propriedades sensoriais do produto final. O objetivo deste trabalho foi investigar a capacidade de duas linhagens de Saccharomyces cerevisiae em inibir a atividade de Brettanomyces custersianus na vinificação em tinto e durante a fase inicial de envelhecimento, assim como investigar a capacidade deste microrganismo (Br. custersianus) em inibir a atividade metabólica de Sacch. cerevisiae. Foram realizadas vinificações com 4 inoculações diferentes. O tratamento 1 (T1) foi inoculado com a linhagem neutra Sacch. cerevisiae EMBRAPA 1vvt/97, T2-Sacch. cerevisiae EMBRAPA 91B/84 killer, T3-EMBRAPA 1vvt/97 e Br. custersianus, T4-EMBRAPA 91B/84 killer e Br. custersianus e T5-Br. custersianus. Também foram realizados, testes de velocidade fermentação, inibição ou estímulo do metabolismo e tolerância ao SO2. Durante a fase tumultuosa realizaram-se análises de açúcares redutores totais e etanol. Observou-se que durante todo o período da fermentação, o consumo de substrato de T1 e T2 foi mais rápido, do que em T3 e T4. A velocidade de fermentação da Br. custersianus (T5) foi muito inferior às demais linhagens. Mesmo com uma velocidade de crescimento baixa, a linhagem contaminante quando inoculada juntamente com Sacch. cerevisiae retarda a fermentação tumultuosa, podendo comprometer o processo de vinificação. Br. custersianus (T5) não teve sua atividade metabólica afetada na presença de 125 mg/L de SO2, logo conclui-se que as concentrações normalmente utilizadas no processo de vinificação, 30 a 70 mg/L, não seriam suficientes para impedir sua atividade.Dekkera/Brettanomyces yeasts cause serious problems to the wine, affecting the sensorial properties of the final product. The objective of this work was to investigate the capacity of two strains of Saccharomyces cerevisiae in inhibiting the activity of Brettanomyces custersianus in the vinification in red wine and during the early stage of aging of the wine, as well as to investigate the ability of this microorganism (Br. custersianus) to inhibit metabolic activity of Saccharomyces cerevisiae. Vinifications were performed with 4 different inoculations. Treatment 1 (T1) was inoculated with the neutral strain Sacch. cerevisiae EMBRAPA 1vvt/97, T2-killer Sacch. cerevisiae EMBRAPA 91B/84, T3-EMBRAPA 1vvt/97 and Br. custersianus, T4-EMBRAPA 91B/84 and Br. custersianus and T5-Br. custersianus. There were also carried out tests of speed fermentation, inhibition or stimulation of metabolism and tolerance to SO2. During the tumultuous phase analysis was performed of total reducing sugars and ethanol. It was observed that throughout the period of fermentation, the substrate consumption in T1 and T2 was faster than in T3 and T4. The speed of fermentation of Br custersianus (T5) was much lower than the other strains. Even with a low rate of growth, the strain contaminant when inoculated with Saccharomyces cerevisiae. delays the tumultuous fermentation, being able to compromise the vinification process. Br. custersianus (T5) did not have its metabolic activity affected in the presence of 125 mg/L of SO2, then it was concluded that the concentrations normally used in the vinification process, 30 to 70 mg/L, would not be enough to prevent their activity

Capacity strains of Saccharomyces cerevisiae to inhibit the activity Brettanomyces custersianus during the winemaking

Leveduras do gênero Dekkera/Brettanomyces causam sérios problemas ao vinho, afetando as propriedades sensoriais do produto final. O objetivo deste trabalho foi investigar a capacidade de duas linhagens de Saccharomyces cerevisiae em inibir a atividade de Brettanomyces custersianus na vinificação em tinto e durante a fase inicial de envelhecimento, assim como investigar a capacidade deste microrganismo (Br. custersianus) em inibir a atividade metabólica de Sacch. cerevisiae. Foram realizadas vinificações com 4 inoculações diferentes. O tratamento 1 (T1) foi inoculado com a linhagem neutra Sacch. cerevisiae EMBRAPA 1vvt/97, T2-Sacch. cerevisiae EMBRAPA 91B/84 killer, T3-EMBRAPA 1vvt/97 e Br. custersianus, T4-EMBRAPA 91B/84 killer e Br. custersianus e T5-Br. custersianus. Também foram realizados, testes de velocidade fermentação, inibição ou estímulo do metabolismo e tolerância ao SO2. Durante a fase tumultuosa realizaram-se análises de açúcares redutores totais e etanol. Observou-se que durante todo o período da fermentação, o consumo de substrato de T1 e T2 foi mais rápido, do que em T3 e T4. A velocidade de fermentação da Br. custersianus (T5) foi muito inferior às demais linhagens. Mesmo com uma velocidade de crescimento baixa, a linhagem contaminante quando inoculada juntamente com Sacch. cerevisiae retarda a fermentação tumultuosa, podendo comprometer o processo de vinificação. Br. custersianus (T5) não teve sua atividade metabólica afetada na presença de 125 mg/L de SO2, logo conclui-se que as concentrações normalmente utilizadas no processo de vinificação, 30 a 70 mg/L, não seriam suficientes para impedir sua atividade.Dekkera/Brettanomyces yeasts cause serious problems to the wine, affecting the sensorial properties of the final product. The objective of this work was to investigate the capacity of two strains of Saccharomyces cerevisiae in inhibiting the activity of Brettanomyces custersianus in the vinification in red wine and during the early stage of aging of the wine, as well as to investigate the ability of this microorganism (Br. custersianus) to inhibit metabolic activity of Saccharomyces cerevisiae. Vinifications were performed with 4 different inoculations. Treatment 1 (T1) was inoculated with the neutral strain Sacch. cerevisiae EMBRAPA 1vvt/97, T2-killer Sacch. cerevisiae EMBRAPA 91B/84, T3-EMBRAPA 1vvt/97 and Br. custersianus, T4-EMBRAPA 91B/84 and Br. custersianus and T5-Br. custersianus. There were also carried out tests of speed fermentation, inhibition or stimulation of metabolism and tolerance to SO2. During the tumultuous phase analysis was performed of total reducing sugars and ethanol. It was observed that throughout the period of fermentation, the substrate consumption in T1 and T2 was faster than in T3 and T4. The speed of fermentation of Br custersianus (T5) was much lower than the other strains. Even with a low rate of growth, the strain contaminant when inoculated with Saccharomyces cerevisiae. delays the tumultuous fermentation, being able to compromise the vinification process. Br. custersianus (T5) did not have its metabolic activity affected in the presence of 125 mg/L of SO2, then it was concluded that the concentrations normally used in the vinification process, 30 to 70 mg/L, would not be enough to prevent their activity

Desenvolvimento de meio de cultura para isolamento de leveduras pertencentes aos gêneros Dekkera e Brettanomyces

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Influence of Brettanomyces custersianus upon the activity of Saccharomyces cerevisiae strains during the tumultuous phase of vinification

The aim of this work was to evaluate the influence of Brettanomyces custersianus on the metabolic activity of Saccharomyces cerevisiae during the tumultuous stage of wine production. The Cabernet Sauvignon grape must with the skin was inoculated with individual cultures of Sacch. cerevisiae and with mixed cultures of Sacch. cerevisiae and Br. custersianus. During the 6-day tumultuous phase of fermentation, the highest ethanol production and the highest sugar consumption were obtained with the strains without B. custersianus. Fermentations carried out with the addition of Brettanomyces metabolites, acetic acid and 4-ethylphenol, showed that only the former inhibited the growth of both Sacch. cerevisiae strains used. In some cases, Br. custersianus could affect the rate higher alcohols production and their final concentrations during the tumultuous phase of vinification

Production of functional killer protein in batch cultures upon a shift from aerobic to anaerobic conditions

The aim of this work was to study the production of functional protein in yeast culture. The cells of Saccharomyces cerevisiae Embrapa 1B (K+R+) killed a strain of Saccharomyces cerevisiae Embrapa 26B (K-R-)in grape must and YEPD media. The lethal effect of toxin-containing supernatant and the effect of aeration upon functional killer production and the correlation between the products of anaerobic metabolism and the functional toxin formation were evaluated. The results showed that at low sugar concentration, the toxin of the killer strain of Sacch. cerevisiae was only produced under anaerobic conditions . The system of killer protein production showed to be regulated by Pasteur and Crabtree effects. As soon as the ethanol was formed, the functional killer toxin was produced. The synthesis of the active killer toxin seemed to be somewhat associated with the switch to fermentation process and with concomitant alcohol dehydrogenase (ADH) activity