| Description |
Chromochloris zofingiensis has been proved as a potential resource for large-scale astaxanthin production, but little information of phytohormones on growth and astaxanthin accumulation could be obtained. This study explored the impact of gibberellic acid-3 (GA3) on growth and astaxanthin generation in heterotrophically growing C. zofingiensis. On Day 16, the astaxanthin yield in 7.5 L fermenters was 89% higher at 0.34 g/L compared to the control. GA3 changed transcription levels of genes linked to carbon metabolism, lipid metabolism, astaxanthin production and ABC transporters. Genes related to astaxanthin biosynthesis, such as phytoene synthase (PSY), phytoene desaturase (PDS), beta-carotenoid hydroxylase (CHYb) and beta-carotenoid ketolase (BKT), were upregulated under GA3 induction. The relative abundances of metabolites involved in carbon metabolisms, such as glucose-1-phosphate (G1P), glucose-6-phosphate (G6P) and glyceraldehyde-3-phosphate (GAP), were altered. By using GA3 and arginine together, the astaxanthin yield increased by 2.3 times to 0.39 g/L over the control. This research proposed novel feasible approaches for heterotrophic C. zofingiensis high astaxanthin production. |
