## 1 Introduction
Enzymatic hydrolysis could create particular structural motifs in the generated peptides, conferring unique structural properties that influence their specific mode of action [20]. Bioactive peptides are generally 3 to 20 amino acid residues in length and have molecular weights of less than 6000 Da [21]. Microalgae, especially those produced at an industrial scale, are considered a promising bioactive peptides source with highly beneficial features. In this frame, peptides with antioxidant potential have been extracted from various Chlorophycae species, mainly _Chlorella vulgaris_, _Naxicula incerta_, _Chlorella ellipsoidea_, and _Dunialella salina_[22; 23; 24; 25; 26]. Anti-inflammatory and antihypertensive peptides have been also isolated from cyanobacteria species belonging to the _Spirulina_ genus [18]. In general, the average protein content of the microalgae biomass is around 25-30% of the total biomass. The protein content and amino acid composition of microalgae biomass are affected by many biotic and abiotic factors and by the genomic variation of species [12; 27]. However, the biological activities of proteins can be determined by their amino acid composition, their size, as well as their 3D conformation. It is important to note that proteins and peptides from cryptophytes are not as well studied and exploited as those from other phyla. _Rhodomonas_ genus is a cryptophyte microalgae that is still poorly studied in terms of its biodiversity, distribution, and food web interactions despite its widespread occurrence in coastal ecosystems. Indeed, it is widely used in aquaculture feed due to its high nutritional value. In fact, _Rhodomonas_ species are able to produce a large variety of metabolites, including proteins, carbohydrates, carotenoids, chlorophylls a and c, phycoerythrin, as well as fatty acids [28]. Regarding its biochemical composition, The _Rhodomonas_ genus is considered a suitable microaplga for a variety of applications in biomedical, biotechnological, and nutraceuticaltial domains due to its high production of commercially valuable compounds such as amino acids, polar lipids, and unsaturated eicosapentaenoic and docosahexaenoicenoic fatty acids [29]. In addition, it represents a source of natural proteins that could compete favorably with the conventional protein sources. In addition, the _Rhodomonas_ genus constitutes a promising candidate for the production of phycoerythrin, an interesting fluorescent protein, used as a natural dye in food and cosmetics as well as a fluorescent marker in biomedical research. This phycobiliprotein is a potential therapeutic agent that has been shown to have multiple benefits in human health thanks to its antioxidant, anticancer, and anti-inflammatory properties [30]. This adds value for the _Rhodomonas_ genus to be considered a potential strain for several promising bioactivities. These potentialities of _Rhodomonas_ proteins could be improved after the hydrolysis and generation of peptides. Hence, it will be interesting to isolate peptides from _Rhodomonas_ species and then study their biological activities, something that has not been previously investigated. In the present study, proteins and peptides hydrolyses were prepared from a strain of the _Rhodomonas_ genus [30] and were then further utilized to investigate their antioxidant and anti-inflammatory activities.