Comparison of two strains of the edible cyanobacteria Arthrospira: Biochemical characterization and antioxidant properties

Arthrospira is a cyanobacteria broadly cultivated worldwide due to its high nutritional value, metabolites with therapeutic properties, non-toxic character and easy culture. The genus Arthrospira has been historically confused with the genus Spirulina (with potential toxicity) therefore, an accurate taxonomic identification of strains for food applications, is essential. In this study we compared two strains of Arthrospira with remarkable morphological differences, preliminary classified as Arthrospira maxima (CCM-UdeC 040) and Arthrospira platensis (CCM-UdeC 136). Despite of their morphological differences, we confirmed that both strains belong to the same genetic species, according to their ribosomal ITS (internal transcribed spacer) sequences. We also compared the biochemical composition of both strains, including analysis of antioxidant properties of their aqueous protein extracts, both crude, as well as, hydrolyzed with commercial proteases. Biotechnological potential of these strains as raw material for nutraceutical and functional food markets is discussed. Strain CCM-UdeC 040 showed the highest biotechnological potential so further studies should be conducted for optimizing its culture conditions. •Two Arthrospira strains were identified as belonging to the same genetic species.•Morphological, biochemical and functional attributes were different between strains.•Protein hydrolysis increased antioxidant properties of Arthrospira's extracts.•Strain CCM-UdeC 040 had higher potential as raw material for food and nutraceuticals.•Next step is optimizing biomass production process for strain CCM-UdeC 040.