Genomics and lipidomics analysis of the biotechnologically important oleaginous red yeast Rhodotorula glutinis ZHK provides new insights into its lipid and carotenoid metabolism

Abstract

Background: Rhodotorula glutinis is recognized as a biotechnologically important oleaginous red yeast, which synthesizes numerous meritorious compounds with wide industrial usages. One of the most notable properties of R. glutinis is the formation of intracellular lipid droplets full of carotenoids. However, the basic genomic features that underlie the biosynthesis of these valuable compounds in R. glutinis have not been fully documented. To reveal the biotechnological potential of R. glutinis, the genomics and lipidomics analysis was performed through the Next-Generation Sequencing and HPLC-MS-based metabolomics technologies. Results: Here, we firstly assemble the genome of R. glutinis ZHK into 21.8 Mb, containing 30 scaffolds and 6774 predicted genes with a N50 length of 14, 66,672 bp and GC content of 67.8%. Genome completeness assessment (BUSCO alignment: 95.3%) indicated the genome assembly with a high-quality features. According to the functional annotation of the genome, we predicted several key genes involved in lipids and carotenoids metabolism as well as certain industrial enzymes biosynthesis. Comparative genomics results suggested that most of orthologous genes have underwent the strong purifying selection within the five Rhodotorula species, especially genes responsible for carotenoids biosynthesis. Furthermore, a total of 982 lipids were identified using the lipidomics approaches, mainly including triacylglycerols, diacylglyceryltrimethylhomo-ser and phosphatidylethanolamine. Conclusion: Using whole genome shotgun sequencing, we comprehensively analyzed the genome of R. glutinis and predicted several key genes involved in lipids and carotenoids metabolism. By performing comparative genomic analysis, we show that most of the ortholog genes have undergone strong purifying selection within the five Rhodotorula species. Furthermore, we identified 982 lipid species using lipidomic approaches. These results provided valuable resources to further advance biotechnological applications of R.glutinis.