Designing and Demonstrating the Use of a Bioluminescent Genetic Tool Set in Scheffersomyces stipitis

Abstract

Scheffersomyces stipitis is the most efficient xylose fermenting yeast currently characterized, which could potentially be utilized in a lignocellulosic fermentation consortium. The genetics of S. stipitis are not as well studied as other species of yeast because S. stipitis is a member of a group of yeast known as the “CUG clade”. Yeast species in the “CUG clade” translate the codon CUG differently from most eukaryotic organisms, instead adding a serine to the protein product instead of a leucine. This alternative translation inhibits the modularity of established selectable markers and reporter systems such as CBG99 in Saccharomyces cerevisiae. Foreign genes need to be codon optimized, changing CTG codons into different leucine codons in order to allow the proteins coded from these genes to retain their native amino acid sequence, structure and function. The work presented in this thesis demonstrate a codon optimized bioluminescent tool set used in S. stipitis, as well as what it can be used for.