Improved lipid productivity of Chlamydomonas globosa and Oscillatoria pseudogeminata as a biodiesel feedstock in artificial media and wastewater

Abstract

Chlamydomonas globosa and Oscillatoria pseudogeminata were grown under different growth conditions on artificial and agricultural wastewater as growth media for biodiesel production. C. globosa and O. pseudogeminata were able to grow in a range of temperatures from 15 to 37 °C and the maximum percentage of total lipid productivity/dry weight was attained after one week of incubation. The optimal pH and light intensity for the growth and lipid productivity were 8.5 and 1000 lux, respectively. The non-irradiated microalgae showed higher growth and lipid content than the irradiated ones with gamma radiation at different doses. The optimal growth and lipid productivity for the algal strains were reached at N/P ratio: 45 using 0.05 and 0.00174 gl^-1 for nitrogen and phosphorus concentrations, respectively. The percentages of the produced lipid in sterilized agricultural wastewater compared to the lipids produced in the modified BG-11 were 69% for C. globosa and 76% for O. pseudogeminata. The most common fatty acids of the two algal strains were palmetic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. According to the obtained results in this study, C. globosa and O. pseudogeminata were found to be highly efficient in producing total lipids for biodiesel and can be used in artificial media and wastewaters as growth media for biodiesel production.