|Title||Enhancement of co-production of nutritional protein and carotenoids in Dunaliella salina using a two-phase cultivation assisted by nitrogen level and light intensity|
|Author(s)||Sui, Yixing; Muys, Maarten; Waal, Dedmer B. Van de; Adamo, Sarah D'; Vermeir, Pieter; Fernandes, Tânia V.; Vlaeminck, Siegfried E.|
|Source||Bioresource Technology 287 (2019). - ISSN 0960-8524|
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Food - Microalgae - Nitrogen limitation - Pigment - Single-cell protein|
Microalga Dunaliella salina is known for its carotenogenesis. At the same time, it can also produce high-quality protein. The optimal conditions for D. salina to co-produce intracellular pools of both compounds, however, are yet unknown. This study investigated a two-phase cultivation strategy to optimize combined high-quality protein and carotenoid production of D. salina. In phase-one, a gradient of nitrogen concentrations was tested. In phase-two, effects of nitrogen pulse and high illumination were tested. Results reveal optimized protein quantity, quality (expressed as essential amino acid index EAAI)and carotenoids content in a two-phase cultivation, where short nitrogen starvation in phase-one was followed by high illumination during phase-two. Adopting this strategy, productivities of protein, EAA and carotenoids reached 22, 7 and 3 mg/L/d, respectively, with an EAAI of 1.1. The quality of this biomass surpasses FAO/WHO standard for human nutrition, and the observed level of β-carotene presents high antioxidant pro-vitamin A activity.