Influence of CO2 and light spectra on the enhancement of microalgal growth and lipid content

Abstract

The effect of different light spectrum and CO2 concentrations on the growth and lipid content of Micractinium pusillum and Ourococcus multisporus was investigated. The highest biomass yields (2.9 and 2.6 g-dry cell weight l(-1)) were observed for M. pusillum and O. multisporus, respectively, at 5% CO2 with red light illumination. Red light spectrum with 5% CO2 supported the highest lipid contents (20% and 27%) and lipid productivity (32 and 36 mg l(-1) d(-1)) for M. pusillum and O. multisporus, respectively. The highest fatty acid methyl esters content for both microalgal species was observed under red light spectrum and 5% CO2 conditions, with the oleic acid fraction ranging between 35% and 37%. This study showed that the red light spectrum and 5% CO2 were the optimum conditions for maximum growth, lipid content and lipid productivity of both microalgae species, which could be further exploited to establish a microalga-based biodiesel production strategy.