Produção de álcoois superiores por linhagens de Saccharomyces durante a fermentação alcoólica

Abstract

RESUMO:A produção de álcoois superiores pelas leveduras Saccharomyces cerevisiae M-300-A, Saccharomyces uvarum IZ-1904 e levedura de panificação (Saccharomyces cerevisiae) foi estudada em diversas condições de temperatura, concentração de sacarose, pH, fontes de nitrogênio e com inibidor 2-4 dinitrofenol (DNP). Em todas as condições estudadas, a levedura Saccharomyces uvarum IZ-1904 apresentou a menor formação de álcoois superiores enquanto a levedura de panifícação apresentou os teores mais elevados. Com o aumento de temperatura e da concentração de sacarose ocorreu maior formação de álcool isoamílico pelas leveduras estudadas. Em pH 4,5 ocorreu menor produção de álcoois superiores do que em pH 3,0. Na presença do inibidor DNP ocorreu significativa redução (p< 0,05) nos teores de álcool isoamílico. As leveduras utilizadas não apresentaram o mesmo comportamento em relação ao sulfato de amônio e uréia quanto a formação de álcoois superiores. Descritores: álcoois superiores, Saccharomyces, fermentação alcoólica. PRODUCTION OF HIGHER ALCOHOLS BY Saccharomyces STRAINS DURING ALCOHOLIC FERMENTATIONABSTRACT: The production of higher alcohols by Saccharomyces cerevisiae M-300-A, Saccharomyces uvarum IZ-1904 and baker's yeast (5. cerevisiae) was studied under several temperature conditions, sucrose level, pH, nitrogen sources and with 2-4 dinitrophenol (DNP). The yeast IZ-1904 showed lower production of higher alcohols than other yeasts in all conditions studied. With the increase of temperature and higher level of sucrose an increase of isoamyl alcohol production was observed. A lower formation of higher alcohols was observed at pH 4.5 than at pH 3.0. With the addition of DNP occurred a significant reduction in isoamyl alcohol content. The yeasts did not show the sanie production of higher alcohols in relation to urea and ammonium sulfate.

Studies on the kinetic parameters for alcoholic fermentation by flocculent Saccharomyces cerevisiae strains and non-hydrogen sulfide-producing strains

“…Various factors such as strain, pH and the temperature of the medium also influence the production of glycerol (Rankine & Bridson, 1971). Gutierrez (1991) studied the effects of sugar concentration (8-16% sucrose) on fermentations conducted with three S. cerevisiae strains and observed a significant increase in the production of glycerol with an increase in the concentration of sucrose in the medium (from 0.31 g/100 ml at 8% to 0.56 g/ 100 ml at 16%). According to Radler & Schutz (1982), the production of glycerol depends principally on the yeast strain used.…”

Wavelet Transform as a tool in the monitoring of fermentative processes through image processing

“…The synthetic culture medium, proposed by Gutierres (1993), was prepared. Discontinuous fermentations were performed to obtain data on growth/concentration of microorganism [8]. The microorganism used in the growth tests was the yeast Saccharomyces cerevisae.…”

Monitoring of Fermentative Processes via Image Processing Online and in Situ

“…Gravimetric quantification using graduated centrifuge tubes. Immediately after centrifugation, the total volume of centrifuged sample was read, and the total volume of decanted volume was obtained by volume percentage of yeast from the medium [8].…”