Enhanced biomass production of Scenedesmus obliquus in a flat-panel photobioreactor, grown in photoautotrophic mode

A study on biomass accumulation was conducted with Scenedesmus obliquus CCAP 276/3A in flat-panel photobioreactor, grown in photoautotrophic mode. It is one of the prime prerequisites to increase the economic feasibility and acceptance of microalgal feedstock for biofuel production, besides high lipid concentration. Various physicochemical parameters considered for evaluation during the present study were illumination conditions between 50 and 200 µmol m−2 s−1, temperatures between 22 and 30°C, pH varying from 7 to 9, and with and without the use of buffers. Among the variables, growth temperature and buffering with TRICINE had a pronounced effect on the enhanced biomass production. With an illumination intensity of 150 µmol m−2 s−1 at 24°C in the TRICINE-buffered Bold's Basal medium (pH 8.5) the maximum biomass concentration achieved was 1.76 gL-1. The specific growth rate of the microalga was found to be 1.28 d−1. Under these optimized conditions, the maximum lipid accumulation in Scenedesmus obliquus was found to be 33% (w/w). The compositional analysis of the neutral lipids indicated the predominance of palmitic acid and linoleic acid, accounting for 28% and 22.5%, respectively.