DEVELOPING MOLECULAR TOOLS TO IMPROVE TERPENOIDS PRODUCTION IN RHODOSPORIDIUM TORULODIES

Abstract

Terpenoids produced are usually highly toxic to the host cells, leading to early shut-off of the biosynthesis. Red yeasts, particularly species in Rhodosporidium, were considered high-yielding platform for terpenoids production due to their remarkable potentials for lipid production and their well-known roles as natural producers of lipid and carotenoids. We first investigated the putative strong promoters in Rhodosporidium. Among these, two strongest ones, namely PRg2ENO1 and PRg2FAD1, were characterized and a putative cis-acting element was identified in Rg2ENO1 sequence. Meanwhile, we used random T-DNA insertional mutagenesis to generate a mutant pool of Rhodosporidium toruloides and screened for mutants that were able to grow at high levels of monoterpene, menthol. Two such mutants, RtDPR1 and Rt0S08, were successfully identified, which helps remediating the cytotoxicity issue during terpenoid production and we expect these mutants will be able to significantly enhance terpenoid productivity in this host.