Optimized co-production of lipids and carotenoids from Ettlia sp. by regulating stress conditions

[Display omitted] •Ettlia sp. YC001 produces lutein and β-carotene, along with lipids.•Two-stage cultivation was adopted for co-production of lipid and carotenoids.•The highest lutein content was 7.8 mg/g with white light at 25 °C.•Double stress induced the accumulation of lipids (58.2%) and β-carotene (19.5 mg/g). This study used a single strain Ettlia sp. YC001 and two stages to optimize the production of three materials: lipids, lutein, and β-carotene. In the cultivation stage for lutein production, different temperatures, light qualities, and intensities were applied. The highest biomass was obtained at 35 °C, but the maximum lutein productivity of 6.1 mg/L/d achieved at 25 °C. In the stress stage for lipids and β-carotene production, UV-A and nitrogen starvation were applied. While UV stress increased the chlorophyll-a and β-carotene content. The β-carotene, oleic acid, and lipids significantly increased under nitrogen starvation with a high light intensity of 1200 µmol/m2/s, plus the Ettlia sp. changed from green to red. The results showed that Ettlia sp. can be an effective microalga for the co-production of lutein, β-carotene, and biodiesel.