Transcriptome-based analysis of euglena gracilis lipid metabolic pathways under light stress

Abstract

To investigate lipid metabolism pathways and the genes encoding essential enzymes regulating these pathways, the present study was conducted to analyze the transcriptome of Euglena gracilis cultured under light and dark conditions for 5 days using the Illumina HiSeq 4000 sequencing platform. A total of 120,086 unigenes were obtained using Trinity assembly software, of which 48,031 were annotated. Through bioinformatics analysis, genes associated with E. gracilis lipid metabolism pathways were identified, and pathways for fatty acid biosynthesis, fatty acid degradation, and glycerolipid metabolism were preliminarily constructed. In addition, differences in gene expression under different culture conditions were compared. By regulating the activity of acetyl-CoA carboxylase, 3-ketoacyl-ACP synthase II, and phospholipid: diacylglycerol acyltransferase, enzymes associated with fatty acid and glycerolipid degradation may be inhibited or knocked out, thereby increasing fatty acid and glycerolipid content in E. gracilis. This study provides a basis for genetic modification of E. gracilis for construction of a high-quality oil-producing engineered strain.