Enhancement of lipid production in Scenedesmus sp. by UV mutagenesis and hydrogen peroxide treatment.

The high potential UV mutagenized Scenedesmus sp. was obtained in which the cells had a higher biomass and lipid content than the wild type with an increase from 1.9 to 2.4g/L and from 40 to 55% of dry cell weight respectively after 12days. Oxidative stress imposed by H2O2 treatment decreased the biomass of both the wild type and the mutant. The H2O2 treated mutant when grown in BG11 medium showed an increase in biomass which was in contrast to a decreased biomass observed in the H2O2 treated wild type. A 3-fold increase in lipid yield of 1.63g/L was obtained in the oxidative stress-induced mutant compared to the wild type. Overall results indicate that prior treatment of UV-mutagenized Scenedesmus with oxidative stress can increase the total lipid production which, due to its derived methyl ester having acceptable biodiesel properties, can be potentially utilized for biodiesel production.