Effects of calcium, magnesium and sodium chloride in enhancing lipid accumulation in two green microalgae

Abstract

Biodiesel from microalgae has the potential as a sustainable fuel, since some species show exceptionally high lipid accumulation potential under various stresses. Effects of different concentrations of Ca, Mg and NaCl in the growth medium on biomass yield and lipid accumulation of Chlorella vulgaris and Scenedesmus obliquus grown under batch culture mode were investigated. Starvation of Mg showed a marginal rise in lipid content for a short period of time. Ca-starved cultures, however, demonstrated a profound rise in lipid content, i.e. 40% of dry cell wt. (dcw) was recorded against 11.9% control for C. vulgaris and 37% (dcw) against 11.3% for S. obliquus. Under increased concentration of Mg, significant rise in biomass and lipid yield was recorded. Effect of NaCl-induced osmotic stress showed lipid accumulation of approximately 40% (dcw) in both the test algae, whereas the biomass yield was severely affected. The fatty acid profiles under the above stresses were analysed and discussed.

Enhancing Lipid Production of Dunaliella tertiolecta by Manipulating the Interactive Effect of Salinity and Nitrogen

“…As the concentration of NaNO 3 was decreased in the medium, it also resulted in a decrease in lipid productivity. In case of salinity variation, 3 30 Similarly, lipid productivity of our specie was better than that of Dunaliella sp as reported by Mata et al 32 …”

“…However, this increase in biomass was lower compared to the previous experiment which was performed under salinity variation alone. This shows that this concentration of NaNO 3 was not optimum for normal cell growth. Fig.…”

“…14 However, Fig. 1c 3 , which was the highest initial nitrate concentration used in this study. These results were supported by a previous study on Dunaliella where nitrogen stress alone did not result in lipid enhancement.…”

“…Microalgae offer fast growth rate, high carbohydrate, lipid, and have the ability to grow under harsh conditions. 3 Besides the unique features of microalgae, their scale-up applications for biofuels production is as yet uneconomical. 4 Actually, the current level of lipid production (30-40 % of cell biomass) is much lower than its potential.…”

Expression of Synthetic Phytoene Synthase Gene to Enhance β‐Carotene Production in Scenedesmus sp. CPC2

“…Some metal ions, in particular magnesium, are also known as crucial components for the culture of green algae under autotrophic conditions. As shown in Figure A, using higher MgSO 4 concentration could dramatically enhance cell growth of CPC2 strain.…”