Effect of different culture media on the growth and lipids of the green microalgae, Scenedesmus obliquus and Micractinium reisseri as a feedstock for biodiesel production

Abstract

The aim of this study was to investigate the growth, lipid content and lipid productivity of the biodieselpromising microalgae Scenedesmus obliquus and Micractinium reisseri grown in batch culture using four differentfreshwater growth media, namely Chu-10, KC, Flory and Kuhl’s medium to identify the most suitable medium for high lipidproduction for each species. The Results confirmed that Kuhl and KC showed the highest biomass productivity for S.obliquus and M. reisseri (0.05 and 0.07g L-1 d-1, respectively). The Lipid content and lipid productivity were estimated atfour different growth phases (early, middle, late exponential and stationary phase).The results revealed that, M. reisserishowed the highest lipid productivity at stationary phase (17.08 mg L−1d−1), while S. obliquus showed lipid productivity of12.61 mg L−1d−1 which was insignificant with that at the late exponential phase (12.55 mg L−1d−1). The fatty acids profile ofS. obliquus and M. reisseri at stationary growth phase showed that both of them were suitable as feedstock for biodieselproduction because of their high saturated fatty acids content that represented by 81.34% and 72.51% of the total fattycontent, respectively. Palmitic acid (C16:0) was represented by 15.74 and 16.06 % in the two studied species, respectivelythat increase the biodiesel quality for each strain. This study suggests M. reisseri cultivated on KC medium to provide highlipid productivity which offers a promise to be one of the sources of biodiesel.