Ettlia sp. YC001 showing high growth rate and lipid content under high CO2

Over 100 green-colored colonies were isolated from environmental samples when cultivating on a BG11 agar medium, and 4 strains showing different morphologies were selected based on light microscopic observation. Among these strains, the microalgal species with the highest growth rate under 10% CO2 was identified as Ettlia sp. YC001 using an 18S rDNA-based phylogenetic analysis and morphological comparison. The highest cell density of 3.10 g/L (based on dry cell weight) and biomass productivity of 0.19 g/L/d were obtained under 5% CO2 after 16 days. The lipid content and productivity were also up to 42% of the dry cell weight and 80.0 mg/L/d, respectively. The color of the Ettlia sp. YC001 culture changed from green to red after a month due to the accumulation of certain carotenoids. Therefore, it would seem that Ettlia sp. YC001 is appropriate for mitigating CO2 due to its high biomass productivity, and a suitable candidate for producing biodiesel and high-value products.

► Ettlia sp. YC001 showing high biomass productivity even under a high CO2 of 5–10%. ► A high lipid content of 42% (dry cell weight) and accumulation of certain carotenoids. ► Ettlia sp. YC001 can be a candidate for producing biodiesel and high-value products.