Influence of the use of rice bran extract as a source of nutrients on xylitol production

Ernesto   Acosta MARTÍNEZ; Juliana Aparecida   Frade SANTOS

Influence of the use of rice bran extract as a source of nutrients on xylitol production

Autores

Ernesto Acosta MARTÍNEZ

Juliana Aparecida Frade SANTOS

Editor

Sociedade Brasileira de Ciência e Tecnologia de Alimentos

Descripción

Xylose-to-xylitol bioconversion using 2.5 or 10% (v/v) rice bran extract was performed to verify the influence of this source of nutrients on Candida guilliermondii metabolism. Semisynthetic medium (SM) and sugarcane bagasse hemicellulosic hydrolysate detoxified with ion-exchange resins (HIE) or with alteration in pH combined with adsorption onto activated charcoal (HAC) were fermented in 125 mL Erlenmeyer flasks at 30 °C and 200 rpm for 72 hours. Activated charcoal supplemented with 2.5% (v/v) rice bran extract was fermented by C. guilliermondii in a MULTIGEN stirred tank reactor using pH 5.0 and 22.9/hour oxygen transfer volumetric coefficient. Higher values of xylitol productivity (0.70, 0.71, and 0.62 g.Lh–1) and xylose-to-xylitol conversion yield (0.71, 0.69, and 0.63 g.g–1) were obtained with 2.5% (v/v) rice bran in semisynthetic medium, ion-exchange resins, and activated charcoal, respectively. Moreover, during batch fermentation, the xylitol volumetric productivity and fermentation efficiency values obtained were 0.53 g.Lh–1 and 61.1%, respectively.