On the Design of <em>Chlorella vulgaris</em> Composition for Potential Food Uses via Manipulation of Cultivation Conditions

Interest in microalga-based technologies has emerged in recent years as a response to environmental challenges and the global food crisis for providing alternative and sustainable food products. This study used temperature variations between 18 and 32 °C, and nitrogen-to-phosphorus (N:P) ratios between 1.9 and 42.6, to model and optimize growth and composition of Chlorella vulgaris, a nutritionally interesting species. Lower temperatures appear ideal for this strain. An increase in average biomass productivity was observed with decreasing temperature, leading to a maximum of 122.27 mgdw L-1 d-1 at 18 °C on the 4th day of cultivation. The maximum productivities for total proteins, fatty acids, carbohydrates, and pigments were, respectively, 26.9 mg L-1 d-1, 26.4 mg L-1 d-1, 16.0 mg L-1 d-1, and 2.41 mg L-1 d-1, all referring to 18 °C. The fatty acid, carotenoid, and amino acid profiles were also ascertained; several indicators suggested that cultivation of this microalga under the aforementioned optimal conditions holds potential for the food industry. The high proportion of polyunsaturated fatty acids, including two essential fatty acids; the high production of lutein; and the presence of several essential amino acids are among the favorable indicators. Overall, the information generated by this study is helpful to support future pilot studies aimed at the commercial production of microalga-derived products.