LAUSR

Many aspects can influence the CO2 biofixation efficiency by microalgae, including CO2 concentration, initial biomass concentration and photobioreactor configuration. This study evaluated two photobioreactors (raceway and tubular) and two initial biomass concentrations (0.2 and 0.4 g L−1) in the growth parameters and in the CO2 biofixation by Spirulina sp. LEB 18 cultures. The carbon source was replaced by 10% (v/v−1) of CO2 (0.05 vvm). Tubular photobioreactor cultures provided an increase of 43 and 62%, respectively, in the maximum specific growth rate and in the CO2 biofixation efficiency, compared with the raceway photobioreactor cultures. The lowest initial biomass concentration evaluated (0.2 g L−1) increased the growth parameter results, with a maximum specific growth rate of 42% higher than the cultures using the highest initial biomass concentration (0.4 g L−1). Spirulina sp. LEB 18 cultures in tubular photobioreactor with 0.2 g L−1 of initial biomass concentration showed a potential for CO2 biofixation.