## 1 Introduction  
The overloading of nutrients in aquatic ecosystems provides ideal conditions for the excessive growth of marine organisms, which comprise approximately half of the total global biodiversity [1]. In parallel, oxidative stress and reactive oxygen species (ROS) have been increased in these kinds of environments, which could cause severe cellular damage [2]. Therefore, in order to defend against oxidative bursts, microalgae and other oceanic organisms have developed multiple defensive mechanisms, mainly the accumulation of valuable biomolecules, which could stimulate antioxidant activity [3]. Thus, the interest in extracting new antioxidant agents from aquatic species has remarkably increased. Aquatic ecosystems include a great diversity of marine species, 245,500 of which have been identified thanks to advances in molecular biology. All of these organisms constitute blue biotechnology and are classified into different major categories, namely, vertebrates, invertebrates, bacteria, fungi, and algae. Algae constitute the most abundant resource in the aquatic environment. They are a very diverse group, approximately 50,000 species of which have been isolated and identified [4]. They are chlorophyllous organisms, classified into macroalgae and microalgae. Macroalgae represent a polyphyletic group of multicellular algae inhabiting the shallow littoral zone with sufficient light to accomplish photosynthesis [5]. Microalgae can be prokaryotic or eukaryotic. Prokaryotic microalgaeare represented by cyanobacteria, which possess a wide variety of ecological characteristics that have allowed them to colonize most aquatic ecosystems, while eukaryotic microalgae are classified into _Chlorophyceae_, _Rhodophylleae_, and _Phaeophyceae_. Their chloroplasts contain several flattened thylakoids that contain chlorophylls and other pigments responsible for their pigmentation. Microalgae cultivation is an effective process used for CO\({}_{2}\) sequestration and carbon footprint reduction [6]. Thus, microalgae biomass production is a promising strategy to combine the reduction of anthropogenic emissions with the production of biomass useful in various fields [7; 8; 9]. Microalgae biomass has been considered as a new source of metabolites [3; 10; 11; 12]. They are highly explored due to their richness in valuable molecules, mainly proteins, polysaccharides, fatty acids, and pigments. In particular, many microalgae strains, such as _Arthospira_ sp., _Aphanizomenon_ sp., _Dunialella_ sp. and _Chorella_ sp., are characterized by their high protein content, exceeding 50%, and are actually used as human food supplements [8]. In fact, they have protein and amino acid profiles with high dietary value. Anti-inflammatory activity has been also reported for multiple compounds derived from different microalgae species, such as those belonging to _Chlorella_, _Dunialella_, and _Phaeodactylum_ genera [13; 14]. Such products could prevent various occurrences caused by inflammations, such as the increase in protein denaturation, increase in vascular permeability, and biological membrane alteration [15]. In this frame, the isolation of bioactive peptides is a novel approach attracting scientists' attention. Nowadays, several therapeutic peptides, obtained by the proteolytic degradation of some proteins present in bacteria, plants, and animals, have been reported as potential therapeutic agents [16]. Those peptides are characterized by specific biological activities coupled with low toxicity. Antioxidant and anti-inflammatory capacities are among the most popular biological activities of peptides [17; 18]. Both animal and plant proteins are known to contain potential bioactive sequences; however, most studies to date have involved milk proteins [19]. The most common and easiest method by which produce bioactive peptides is enzymatic hydrolysis [16]. It generates peptides with specific molecular weights and a specific amino acid composition. In addition, it allows the control of the hydrolysis process as well as the hydrolysis degree.