Operational strategies for maximizing CO2 utilization efficiency by the novel microalga Scenedesmus obliquus SA1 cultivated in lab scale photobioreactor

The present study deals with optimization of operational parameters to maximize the CO2 utilization efficiency by microalga: Scenedesmus obliquus SA1 (KC733762) previously isolated in our laboratory. SA1 strain was cultivated in a cylindrical glass photobioreactor under 15% CO2 concentration at various operational conditions. At a light intensity of 4351 lx, a CO2 sparging duration of 12 h per day and flow rate of 0.43 L per hour, a maximum biomass concentration of 3.32 ± 0.022 g L− 1, a maximum specific growth rate of 1.24 ± 0.028 d− 1, and a maximum CO2 utilization efficiency of 10.23% were obtained, which were higher than most of the relevant literature reports. Total inorganic carbon and total organic carbon concentrations of the cultivation medium were monitored with time, which showed increasing trends with an increase in biomass concentration.