Microbiologia

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840

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Resultados da Pesquisa

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    Screening of yeasts isolated from brazilian environments for the 2-Phenylethanol (2-PE) production
    (Biotechnology and Bioprocess Engineering, 2018-06) Lima, Lorena Azevedo de; Diniz, Raphael Hermano Santos; Queiroz, Marisa Vieira de; Fietto, Luciano Gomes; Silveira, Wendel Batista da
    Phenylethanol alcohol, or 2-phenylethanol (2-PE) production by yeasts has been considered a promising alternative to its chemical synthesis. In order to evaluate the potential of yeast strains isolated from different Brazilian environments, we evaluated the 2-PE production of 267 strains. Among them, the Kluyveromyces marxianus CCT 7735 yeast stood out as being the best 2-PE producer. The K. marxianus CCT 7735 growth was impaired by 2-PE; nevertheless, this effect is less pronounced than the inhibition reported for certain Saccharomyces cerevisiae strains. The maximum 2-PE titer obtained under optimized conditions was 3.44 g/L, 28% higher than the titer achieved under unoptimized conditions. The optimized conditions were: 30ºC, and glucose and L-phe concentrations of 3.0 and 4.0 g/L, respectively. Moreover, the specific production rate of 2-PE increased twofold compared to the unoptimized conditions.
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    Optimizing ethanol production by thermotolerant Kluyveromyces marxianus CCT 7735 in a mixture of sugarcane bagasse and ricotta whey
    (Food Science and Biotechnology, 2015-08) Ferreira, Priscila Gonçalves; Silveira, Fernando Augusto da; Santos, Raquel Cristina Vieira dos; Genier, Hugo Leonardo André; Diniz, Raphael Hermano Santos; Ribeiro Jr., José Ivo; Fietto, Luciano Gomes; Passos, Flávia Maria Lopes
    The simultaneous saccharification and fermentation (SSF) process is a promising strategy to obtain ethanol from cellulosic biomass. In this study, sugarcane bagasse was supplemented with ricotta whey to increase the sugar, vitamin, and trace metal concentrations in the fermentation medium. The optimum conditions for SSF ethanol production from a mixture of sugarcane bagasse and ricotta whey produced by Kluyveromyces marxianus CCT 7735 were evaluated considering five factors: cellulase concentration, cellulosic biomass concentration, pH, temperature, and agitation. The highest ethanol yield was 49.65 g/L with a cellulosic biomass of 80 g/L, pH value of 5.05, agitation at 65 rpm and temperature of 39.2°C. The results demonstrated that a mixture of the cellulosic residue of sugarcane bagasse and ricotta whey is promising for ethanol production because the ethanol yield in the mixture was higher than that in single substrate of sugarcane bagasse.
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    Optimizing ethanol production by thermotolerant Kluyveromyces marxianus CCT 7735 in a mixture of sugarcane bagasse and ricotta wh
    (Food Science and Biotechnology, 2015-05-01) Ferreira, Priscila Gonçalves; Silveira, Fernando Augusto da; Santos, Raquel Cristina Vieira dos; Genier, Hugo Leonardo André; Diniz, Raphael Hermano Santos; Ribeiro Jr., José Ivo; Fietto, Luciano Gomes; Passos, Flávia Maria Lopes; Silveira, Wendel Batista da
    The simultaneous saccharification and fermentation (SSF) process is a promising strategy to obtain ethanol from cellulosic biomass. In this study, sugarcane bagasse was supplemented with ricotta whey to increase the sugar, vitamin, and trace metal concentrations in the fermentation medium. The optimum conditions for SSF ethanol production from a mixture of sugarcane bagasse and ricotta whey produced by Kluyveromyces marxianus CCT 7735 were evaluated considering five factors: cellulase concentration, cellulosic biomass concentration, pH, temperature, and agitation. The highest ethanol yield was 49.65 g/L with a cellulosic biomass of 80 g/L, pH value of 5.05, agitation at 65 rpm and temperature of 39.2°C. The results demonstrated that a mixture of the cellulosic residue of sugarcane bagasse and ricotta whey is promising for ethanol production because the ethanol yield in the mixture was higher than that in single substrate of sugarcane bagasse.