Prospecting for Oleaginous and Robust Chlorella spp. for Coal-Fired Flue-Gas-Mediated Biodiesel Production

Prospecting for robust and high-productivity strains is a strategically important step in the microalgal biodiesel process. In this study, 30 local strains of Chlorella were evaluated in photobioreactorsfor biodiesel productionusing coal-fired flue-gas. Three strains (M082, M134, and KR-1) were sequentially selected based on cell growth, lipid content, and fatty acid composition under autotrophicand mixotrophicconditions. Under autotrophicconditions, M082 and M134 showed comparable lipid contents (ca. 230 mg FAME [ fatty acid methyl estersderived from microalgal lipids]/ g cell) and productivities (ca. 40 mg FAME/L·d) versus a reference strain (KR-1) outdoors with actual flue-gas(CO2, 13%). Interestingly, under mixotrophicconditions, M082 demonstrated, along with maximal lipid content (397 mg FAME/ g cell), good tolerance to high temperature (40 °C). Furthermore, the fatty acid methyl estersmet important international standards under all of the tested culture conditions. Thus, it was concluded that M082 can be a feedstock of choice for coal-fired, flue-gas-mediated biodiesel production.