Project description:Haematococcus pluvialis transcriptome analysis The genetic transcriptome details of astaxanthin biosynthesis were analysed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). SRP062153 PRJNA292140
Project description:Haematococcus pluvialis has been used to produce the ketocarotenoid antioxidant, astaxanthin. Currently, heterotrophic cultivation of H. pluvialis is limited by slow growth rates. This work aims to address this challenge by exploring the mechanisms of acetate metabolism in Haematococcus. Chemical mutagenesis and screening identified H. pluvialis strain KREMS 23D-3 that achieved up to a 34.9% higher cell density than the wild type when grown heterotrophically on acetate. An integrative proteomics and phosphoproteomics approach was employed to quantify 4,955 proteins and 5,099 phosphorylation sites from 2,505 phosphoproteins in the wild-type and mutant strains of H. pluvialis. Among them, 12 proteins were significantly upregulated and 22 significantly downregulated in the mutant while phosphoproteomic analysis identified 143 significantly upregulated phosphorylation sites on 106 proteins and 130 downregulated phosphorylation sites on 114 proteins. Upregulation of anaphase promoting complex phosphoproteins and downregulation of a putative cell cycle division 20 phosphoprotein in the mutant suggests rapid mitotic progression, coinciding with higher cell division rates. Upregulated coproporphyrinogen oxidase and phosphorylated magnesium chelatase in the mutant demonstrated altered nitrogen partitioning towards chlorophyll biosynthesis. The large proportion of differentially expressed phosphoproteins suggests phosphorylation is a key regulator for protein expression and activity in Haematococcus. Taken together, this study reveals the regulation of interrelated acetate metabolic pathways in H. pluvialis and provides protein targets that may guide future strain engineering work.
Project description:Herein, we tried to examine the protein composition of EVs derived from cultivation medium of Haematococcus pluvialis (HpEVs) at three growth stages of life cycle, including the green vegetative motile stage, green nonmotile stage, and red nonmotile cyst stage.