Biomass, total lipid production, and fatty acid composition of the marine diatom Chaetoceros muelleri in response to different CO2 levels

The marine diatom Chaetoceros muelleri grown under air (0.03% CO2), 10%, 20%, and 30% CO2 conditions was evaluated to determine its potential for CO2 reduction coupled with biodiesel production. The results indicated that C. muelleri grows well with high CO2 aeration levels (10–20%) and is induced to accumulate lipids under 10–30% CO2. In particular, the highest values of the maximum biomass concentration (1.059 g L−1), maximum specific growth rate (0.868 d−1), maximum biomass productivity (0.272 g L−1 d−1), maximum CO2 biofixation (0.428 g L−1 d−1), and total lipid (43.40% dry weight) and neutral lipid contents were all obtained with 10% CO2 aeration. Moreover, the analysis of the fatty acid composition of C. muelleri revealed the predominance of C14–C18 fatty acids (>90%) and saturated and monounsaturated fatty acids (>80%) under all CO2 levels. The results suggest that C. muelleri has great potential to biodiesel production using flue gases.