Sugar metabolization of Saccharomyces cerevisiae with transporter of sucrose and different invertase activity / Metabolização de açúcares em linhagens de Saccharomyces cerevisiae com e sem transportador de sacarose e diferentes atividades de invertase

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The aim of this work was to evaluate the metabolic profile in the utilization of sugars, using different yeast strains (BG-1, CAT-1, FLEISHMANN, PE-2, 1403-7A and LCM001) with different growth medium and also to analyze behavior and the invertase activities of these yeast strains during fermentative process with recycling, similar to the industrial process. The following parameters were used: ethanol production, biomass formation, trealose production, glycogen, glycerol, ethanol yield and fermentation efficiency. The trials were divided into three parts: First was activity quantification of invertase using different yeast strains, with a mix of molasses and water (13% ART), the second was analyzed the metabolization profile with different growth medium using YEP added 2% of sugars (glucose, sucrose, or glucose + sucrose), and the third it was the alcoholic fermentation with 4 yeast cell recycles, using wort of molasses and juice ( 13 % ART), The first three were utilized to evaluate the fermentation yield and also theirs indicatives (trealose, glycogen, viability within others) and, the last one was performed to study the profile of sugars metabolization in fermentation conditions. The results showed that those yeasts produced different invertase activities (BG-1 = 7,34; FLEISCHMANN = 5,75; CAT-1 = 3,76; PE-2 = 2,39 gART.h-1.gbiomass; 1403-7A and LCM001 did not have invertase activity), different velocity of sucrose hydrolysis, as much as medium growth as worts (BG-1 and FLEISCHANN = 2 h; CAT-1 = 3h; PE-2 = 4h; 1403-7A = 24 h and LCM001 = >24 h), also as the velocity of sugars metabolization present on this medium. It can be concluded that the invertase activity is dependent of yeast strain, as the velocity of sugars metabolization in growth medium and wort. The profile analysis of metabolization of sugars did not allow to identify the presence of sucrose transporter. In general, the selected yeasts present the best fermentation performance. On the other hand, it was observed the strains with sucrose transportation did not show stress. The major problem of these yeasts were the high fermentation time and low propagation rate, and a decrease of the viability.

ASSUNTO(S)

invertase sacarose sucrose transporter fermentação alcoólica invertase activity enzimas sacarolíticas cana-de-açúcar agt1 permease alcoholic fermentation

ACESSO AO ARTIGO

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