## 1 Introduction  
Microalgae can produce large amounts of lipids, proteins, and carbohydrates--key components in the formulation of bio-based products such as bioplastics [1; 2] and edible films and coatings [3]--offering a sustainable alternative to conventional plastic packaging. Microalgae are rich in a wide range of bioactive compounds, including proteins (essential amino acids and bioactive peptides), polyunsaturated fatty acids (EPA and DHA), pigments (chlorophylls, carotenoids, and phycobiliproteins), polysaccharides, vitamins, polyphenols, and phytosterols [4; 5]. However, data on the chemical composition and nutritional value of algal biomass are available for only a limited number of commercially utilized species [6]. These data vary considerably due to the immense diversity and heterogeneity of algal species, as well as the wide variations in environmental conditions during cultivation, harvesting, and biomass processing [7; 8]. Microalgae contain pigments that impart different colors. These pigments are classified into chlorophylls (\(a\) and \(b\)), carotenoids (carotenes and xanthophylls), and phycobiliproteins. Due to structural differences, chlorophyll \(a\) appears blue-green in color, whereas chlorophyll \(b\) exhibits a green-yellow hue. Carotenoids are responsible for orange and red coloration. Phycobiliproteins--complexes of phycobilins bound to proteins--exhibit distinct spectral properties. The four main classes of phycobiliproteins are allophyocyanin (bluish green), phycocyanin (blue), phycoerythrin (red), and phycoerythrocyanin (orange) [9]. Seven microalgae species were studied as part of the Extratoteca Project, with biomass produced by the company A4F, due to their high potential for sustainable biotechnological applications and market relevance. Each species offers unique metabolic profiles and bioactive compounds that are of growing interest in fields such as functional foods, nutraceuticalals, cosmetics, aquaculture, and pharmaceuticals. _Limnospira_ sp. (former _Arthospira_ sp.) is a genus of cyanobacteria capable of adapting to diverse aquatic environments, including freshwater and alkaline brackish lakes. It represents a promising component of the aquaculture bioeconomy due to its high biomass productivity and expected market growth. _Limnospira_ sp. is rich in proteins, photosynthetic pigments, and various bioactive compounds. Traditionally used in nutrition and therapeutic applications, it is also employed in wastewater treatment and biofuel production. More recently, it has demonstrated potential in the development of pharmaceuticals, wound-healing dressings, photosensizers for photodynamic therapy, tissue engineering,and anticancer therapies. Additionally, _Linnospira_ sp. is being explored in industrial applications for biopolymer production, fuel cells, and photovoltaic technologies, thereby contributing to climate change mitigation [10]. _Dunaliella_ sp. is a genus of predominant marine chlorophyte algae, with freshwater species being relatively rare. It is widely used for the recovery of high-value compounds (\(\beta\)-carotene, glycerol, proteins, lipids), which can be extracted from this microalgae, or as whole-cell biomass, which can be used in e.g., animal feed, functional foods, and dietary supplements. Due to its high carotenoid content, _Dunaliella_ sp. exhibits therapeutic properties, including antioxidant, anticancer, and anti-inflammatory effects. It is particularly rich in \(\beta\)-carotene, making it valuable to the food and cosme industries as a natural colorant and antioxidant. Lipids from _Dunaliella_ sp., particularly fatty acids, are of interest for biofuel production, and the whole organism is also used in bioremediation applications such as wastewater treatment [11]. _Lobosphaera_ sp. is primarily a freshwater chlorophyte, although some species are found in marine environments. It produces high-value metabolites with potential pharmaceutical and nutritional applications.