Mixotrophic Cultivation of Scenedesmus dimorphus for Enhancing Biomass Productivity and Lipid Yield

Algal lipids are being used extensively for the production of environment-friendly biofuels nowadays. However, quantity and quality of the extracted lipids are key prerequisites for the production of quality biofuels. The current study was carried out to analyze biomass productivity, lipid content and fatty acid profile of a pre-characterized oleaginous microalgal species ( Scenedesmus dimorphus ) raised under mixotrophic conditions using apple-pomace hydrolysate as additional source of carbon and energy. The above-mentioned parameters were compared for the microalgal biomass raised under mixotrophic as well as photoautotrophic conditions to justify the need of the study. Mixotrophic cultivation yielded significantly higher biomass productivity (140.37 mg L −1 d −1 ) than that of photoautotrophic cultivation (96.55 mg L −1 d −1 ). Lipids’ content (w/w) was also significantly higher for the biomass raised mixotrophically (41%) as compared to that raised photoautotrophically (28%). Lipidome depicted higher concentrations of polyunsaturated fatty acids (palmitic and oleic acids). The frequent availability of polyunsaturated fatty acids (64 mg g −1 of dried biomass) in the lipid contents of algal biomass raised mixotrophically may ensure the production of high-quality biofuel. Our findings of the present study will be fruitful to top up the biofuel balance by the exploited utility of oleaginous microalgal biomass raised under mixotrophic conditions. Graphic Abstract