Metabolic engineering and identification of quantitative traits loci related to HMF tolerance of Saccharomyces cerevisiae strain

Abstract

The urge to replace fossil fuels due to the political, economic and environmental issues have motivated research and development of renewable energy, with bioethanol being one of the main alternatives. Yeasts used in both processes - first and second generation - are responsible for a significant part in the viability of economic models. In the industrial environment, microorganisms are subjected to a variety of stresses that adversely affect production. Thus, tolerate such conditions is essential to obtain satisfactory yields. In the production process of second generation, besides environmental factors, inhibitors generated during the biomass processing constitute a barrier to the metabolism of yeasts, including weak acids, phenolic compounds or furan derivatives such as 5-hydroxymethylfurfural (HMF). In this work, it is proposed the detailed study of FMY001 strain, identified previously as tolerant to high HMF concentration. The genetic basis of its strength will be understood from the detailed study of Quantitative Trait Loci (QTL) related to the observed phenotype. For this, it will be used a flow cytometry-based method to obtain a high number of segregants derivate from FMY001 strain (or hybrid FMY001 x S288c). These will be individually characterized by means of high-throughput screening methods and sequenced for further QTL mapping. The cofactor metabolism - NAD (P) +, NAD (P) H - will also be evaluated by metabolic engineering techniques. Thus, understanding the genetic mechanisms related to the ability of FMY001 strain to tolerate the HMF will contribute significantly to the continued development of more productive strains. (AU)