Enhanced lipid accumulation in microalgae Scenedesmus sp. under nitrogen limitation

Area of Science:

• Biotechnology
• Metabolomics
• Microalgal Physiology

Background:

• Microalgae are promising for sustainable biofuel production within a biorefinery framework.
• Efficient biofuel generation necessitates identifying valuable co-products to offset production costs.
• Fatty acids from microalgae are versatile precursors for bioenergy and pharmaceuticals.

Purpose of the Study:

• To investigate the metabolic changes in Scenedesmus sp. CABeR52 under nitrogen deprivation.
• To elucidate the physiological mechanisms driving lipid accumulation in microalgae.
• To explore the potential of Scenedesmus sp. as a source for biofuel and high-value compounds.

Main Methods:

• Cultivation of Scenedesmus sp. CABeR52 under controlled nutrient-deprived conditions.
• Lipid content analysis using established biochemical assays.
• Metabolomic profiling via gas chromatography-mass spectrometry (GC-MS) to identify key metabolites.

Main Results:

• Nitrogen-deprived Scenedesmus sp. exhibited a 2.0-fold increase in lipid accumulation (278.31 mg.g⁻¹ dry weight).
• Metabolomic analysis revealed upregulated pathways for fatty acid biosynthesis, including citric acid, succinic acid, and 2-ketoglutaric acid.
• Accumulation of trehalose indicated a stress response, and the novel identification of nervonic acid was noted.

Conclusions:

• Nitrogen deprivation triggers significant metabolic reprogramming in Scenedesmus sp., enhancing lipid production.
• Understanding these metabolic pathways is crucial for optimizing microalgae as a sustainable feedstock.
• The identification of nervonic acid opens new avenues for pharmaceutical applications alongside biofuel production.