Fermentation of hexoses and pentoses from sugarcane bagasse hydrolysates into ethanol by Spathaspora hagerdaliae

The present study evaluated 13 strains of yeast for ethanol and xylitol production from xylose. Among them, Spathaspora hagerdaliae UFMG-CM-Y303 produced ethanol yields (Y_P/S) of 0.25 g g^- 1 and 0.39 g g^- 1 under aerobic and microaerophilic conditions, respectively, from a mixture of glucose and xylose in flasks. A pH of 5.0 and an inoculum of 3.0 × 10⁸ cells mL^- 1r resulted in the highest ethanol yields. These conditions were tested in a bioreactor for fermenting a medium containing an enzymatic hydrolysate of sugarcane bagasse with 15.5 g L^- 1 of glucose and 3 g L^- 1 of xylose, and achieved a Y_P/S of 0.47 g g^- 1, in relation to total available sugar. These results suggest that S. hagerdaliae UFMG-CM-Y303 has potential for use in second-generation ethanol studies.