Enhanced lipid accumulation in microalgae Scenedesmus sp. under nitrogen limitation

• Published in: Enzyme and microbial technology 2025-01, Vol.182, p.110546, Article 110546
• Main Authors: Abrha, Getachew Tafere, Makaranga, Abdalah, Jutur, Pannaga Pavan
• Format: Article
• Language: English
• Subjects: Biofuels; Fatty Acids - metabolism; Gas Chromatography-Mass Spectrometry; Lipid Metabolism; Lipids; Metabolic Networks and Pathways; Metabolomics; Microalgae; Microalgae - growth & development; Microalgae - metabolism; Nervonic acid; Nitrogen - metabolism; Nitrogen deprivation; Scenedesmus - growth & development; Scenedesmus - metabolism
• ISSN: 0141-0229; 1879-0909; 1879-0909
• DOI: 10.1016/j.enzmictec.2024.110546

Microalgae-based biofuel production is cost-effective only in a biorefinery, where valuable co-products offset high costs. Fatty acids produced by photosynthetic microalgae can serve as raw materials for bioenergy and pharmaceuticals. This study aims to understand the metabolic imprints of Scenedesmus sp. CABeR52, to decipher the physiological mechanisms behind lipid accumulation under nitrogen deprivation. Metabolomics profiles were generated using gas chromatography-mass spectrometry (GC–MS) of Scenedesmus sp. CABeR52 subjected to nutrient deprivation. Our initial data sets indicate that deprived cells have an increased accumulation of lipids (278.31 mg.g−1 dcw), 2.0 times higher than the control. The metabolomic profiling unveils a metabolic reprogramming, highlighting the upregulation of key metabolites involved in fatty acid biosynthesis, such as citric acid, succinic acid, and 2-ketoglutaric acid. The accumulation of trehalose, a stress-responsive metabolite, further underscores the microalga's adaptability. Interestingly, we found that a new fatty acid, nervonic acid, was identified in the complex, which has a significant role in brain development. These findings provide valuable insights into the metabolic pathways governing lipid accumulation in Scenedesmus sp., paving the way for its exploitation as a sustainable biofuel feedstock. [Display omitted] •Nitrogen deprivation boosts lipid accumulation in Scenedesmus sp., ideal for biofuel.•The metabolic shift under stress favours lipid synthesis over growth.•Key metabolites like citric acid play a pivotal role in lipid production.•Trehalose accumulation aids in stress tolerance and growth regulation.•The fatty acid profile under stress is suitable for biodiesel production.