Chlorella vulgaris cultivation with an additive of magnesium-aminoclay

In integral microalgal biofuel production consisting of microalgal culturing, harvesting, lipid (oil) extraction, oil-to-biodiesel conversion and biodiesel quality improvement, cultivation to improve lipid (oil) content in microalgal cells without inducement of transformants is a booming field of experimentation and application. In the present study, water-solubilized, transparent and cationic-charged and clustered magnesium-aminoclay (MgAC) was utilized as a co-additive in Chlorella vulgaris cultivation. The MgAC effected both an increase of cell size (from ~ 3.524 μm to ~ 4.175 μm size) with low cell density (from 1260 × 106 cells/mL to 511 × 106 cells/mL) and an increase of total lipid content without microalgal cell transformation according to various MgAC loadings (0, 0.25, 0.50, and 1.0 g/L) at the 2.0% CO2 supply. The cationic-charged MgAC clusters wrapped the microalgal cells to create a stressful microenvironment, increasing the intracellular reactive oxygen species (ROS) content. Therefore, additive-MgAC-based microalgal cultivation is herein suggested in a novel microalgal biofuel production.