Application of response surface methodology for optimization of growth and lipids in Scenedesmus abundans using batch culture system

Abstract

Owing to an increased demand for fuel and the depletion of fossil fuels, an alternative source such as algae is currently being exploited for biofuel production. One such potential microalgal candidate for biofuel production is Scenedesmus abundans. The aim of this study was to optimize the growth and lipid content of Scenedesmus abundans in a batch culture system in order to extend its applicability to the commercial production of biodiesel. Optimization of growth parameters such as culture time, concentration of inoculum, and concentration of sodium bicarbonate was performed by Central Composite Design-Response Surface Methodology (CCD-RSM) to maximize production of biomass as well as biofuel yield. The results obtained using CCD-RSM indicate that 30 days, 10% of inoculum and 8 g L⁻¹ of sodium bicarbonate are optimum working parameters to achieve a tentative maximum biomass yield of 0.0391 g per L per day and a maximum lipid content of 26.28% dcw. It was observed that the model prediction values satisfactorily matched the investigated values, within ±2%, for both growth rate and lipid content. Moreover, the individual and synergistic effects of the operational parameters on growth rate and lipid content were analyzed. The obtained experimental data were fitted to Lineweaver–Burk, Langmuir Hanes, Eadie and Eddie Hofstee plots. Among these models, the Langmuir Hanes method was found to provide the best fit, with a coefficient of regression of 0.9888. Consequently, the results of the study indicate that Scenedesmus abundans would be an apt natural source for biodiesel production.