Spathaspora and Scheffersomyces: Promising Roles in Biorefineries

Currently, biotechnologies that aim to optimize the residual lignocellulosic biomass are receiving widespread attention, mainly when it comes to developing integrated systems that allow the generation of multi-products in industrial plants, especially for ethanol production. One of the main bottlenecks for efficient conversion of lignocellulosic biomass into ethanol is the limitation of Saccharomyces cerevisiae, the most widely used yeast in bioethanol production, in metabolizing xylose. This pentose is the main constituent of the hemicellulose fractions in plant cell walls and the second most abundant monosaccharide in lignocellulosic biomass. This challenge is being overcome by the isolation and intense molecular evaluation of new yeast species, mainly members of the genera Spathaspora and Scheffersomyces, since they have shown high capacities for xylose assimilation, which has been corroborated through studies aimed at improving ethanol production and other products via the association of these yeasts with improved fermentation capacity. In this sense, this chapter addresses the recent advances in the identification of novel isolates of the genera Spathaspora and Scheffersomyces, particularly emphasizing the applications of these genera in ethanol and xylitol production.