Maximizing intrinsic value of microalgae using multi-parameter study: conjoint effect of organic carbon, nitrate, and phosphate supplementation

The present study investigates the interactive effect of important growth media components (organic carbon, nitrate, and phosphate) on Scenedesmus sp. Interestingly, simultaneous enhancement of energy storage components and biomass was observed. Six carbon sources taken into consideration in this study affected the microalgal growth profile distinctively. As compared to other studied organic carbon sources, the addition of glucose (5 g L−1) resulted in the highest total biomass (3.7 ± 0.2 g L−1). Further, the combination of 5 g L−1 glucose supplementation with phosphate and nitrate starvation fetched the highest total lipids (331.5 ± 29.4 µg mg−1 and 281.6 ± 9.4 µg mg−1, respectively). Additionally, phosphate starvation with 5 g L−1 glucose supplementation fetched the highest total fatty acid content (118.35 µg mg−1). Carbohydrate content was the highest (1025.5 ± 83.9 µg mg−1) at 5 g L−1 of glucose, 1.5 g L−1 of NaNO3, and 0.04 g L−1 of K2HPO4 without compromising biomass accumulation. Principal component analysis confirmed that carbohydrate and protein concentrations in the algal biomass were closely related to enhanced biomass and chlorophyll concentration and were heavily impacted by NaNO3 in the presence of high organic carbon. This study supported in fetching the nutrient combinations, which increased biomass with wide range of fuel, as well as non-fuel applications.