## 1 Introduction
Its lipid profile--particularly the presence of arachidonic acid, \(\alpha\)-linolenic acid, and eicosapentaenoic acid--underscores its potential for biotechnological applications. _Lobosphaera_ sp. has also shown promise in biofuel production and may serve as a biosorbent in water treatment processes [12; 13]. _Nannochloropsis_ sp. is found in both marine and freshwater environments. It has been studied for a range of applications, including cosmetics, food, feed, and carbon dioxide capture. This microalgae is notable for its skin-protective properties and contains several bioactive compounds such as polyunsaturated fatty acids (PUFAs including EPA), carotenoids (canthaxanthin, \(\beta\)-carotene, zeaxanthin, violaxanthin), and phenolic compounds. _Nannochloropsis_ sp. is beneficial for aquaculture and human nutrition and is used in forms such as pastes, dry powders, or extracts [14; 15; 16]. _Odontella_ sp. is a genus of marine diatoms rich in bioactive metabolites, including fucoxanthin and omega-3 fatty acids. Fucoxanthin has been studied for its antiproliferative effects on bronchopulmonary and epithelial cancer cell lines, and for its anti-inflammatory properties. This microalgae also contains high levels of PUFAs, \(\beta\)-carotene, and other antioxidant pigments, as well as in sulphated polysaccharides and sterols with potential antimicrobial activity [17; 18]. _Porphyridium_ sp. produces sulphated polysaccharides with applications as gelling agents, thickeners, stabilizers, and emulsifiers. These compounds exhibit antioxidant activity and have potential uses as hypolipidaemic, hypoglycaemic, biolubricant agents, and drag reducers. _Porphyridium_ sp. is also employed in the pharmaceutical and cosmetics industries. It contains a range of metabolites, including chlorophyll, carotenoids, and phycoerythrin [19; 20; 21]. _Tetraselmis_ sp. is a marine microalgae known for its broad tolerance to variations in salinity and temperature. It has potential uses in aquaculture wastewater reclamation and biofuel production. This species exhibits several biological activities, including antioxidant, tyrosinase-inhibitory, and antifungal properties [22; 23; 24]. The Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have advocated for dietary shifts to reduce calorie intake from animal sources and to promote the consumption of sustainable, nutrient-dense, and calorie-efficient food products. Among the emerging candidates for functional foods, microalgae have garnered considerable global interest due to their abundance of high-value bioactive compounds with potential health-promoting properties [5]. The use of green extraction techniques employing environmentally friendly solvents is essential for producing extracts suitable for food applications and for enhancing the valorization of these microalgae. Innovativeapplications, such as the development of edible films and coatings based on or enriched with microalgae extracts, may significantly expand their industrial potential [25]. This study aims to evaluate the nutritional value and bioactive properties of seven microalgae species and to investigate the application of their extracts in edible films for food use. Specifically, it focuses on the determination of the nutritional compositions of these microalgae and the bioactivity of their hydroethanolic extracts (obtained via ultrasound-assisted extraction), particularly their antioxidant and antimicrobial activities. Additionally, the application of selected extracts-- especially a lipid-rich extract from _Nannochloropsis_ sp. and bioactive-rich extracts with high antioxidant and antimicrobial properties--is explored for the production of edible films. Therefore, this study presents a comprehensive comparative analysis of the biochemical composition and bioactive properties of _Limnospira_ sp., _Dunaliella_ sp., _Lobosphaera_ sp., _Nannochloropsis_ sp., _Odontella_ sp., _Porphyridium_ sp., and _Tetraselmis_ sp. A key innovation lies in the inclusion of _Lobosphaera_ sp.