Glucose-mediated regulation of glycerol uptake in Rhodosporidium toruloides: Insights through transcriptomic analysis on dual substrate fermentation

The goal of the study is to use Next generation sequencing (RNA-seq) to study the underlying regulation of glycerol metabolism in mixed culture fermentation (glucose and glycerol) of Rhodosporidium toruloides. We sequenced the RNA from 4 different samples in the mixed culture (glucose and glycerol) with 2 replicates each. Transcriptional profiles showed that glycerol might be produced intracellularly and glycerol kinase (GUT1) and glycerol 3–phosphate dehydrogenase (GUT2) enzymes were not down-regulated in the presence of glucose at the transcriptional level. It also showed that this yeast has a different regulation compared to S.cerevisiae. Certain insights into lipid biosynthesis on these mixed cultures are provided at systems level. This analysis provides interesting targets for metabolic engineering in this organism growing on glucose and glycerol. Total 4 phases (glucose-nitrogen excess, glucose-nitrogen limited, diauxic shift, glycerol growth) were choosen and 2 replicates for each phase were pair-end sequenced using Illumina True seq kit on Illumina Hiseq 2000 platform.