Characterization of novel Picochlorum diversity in Caribbean Colombia via 18S rDNA and bioprospecting potential

Microalgae are unicellular, photosynthetic microorganisms widely distributed in marine and freshwater ecosystems, where they serve as primary producers and play a crucial role in aquatic food webs. Their rapid growth rates and the feasibility of cultivation in both open ponds and closed bioreactor systems have made them increasingly attractive for sustainable production of biofuels, functional foods, nutraceuticals, and bioactive compounds. In a study conducted to isolate and characterize native microalgae from the San Andrés Archipelago, two strains were identified via 18S rDNA sequencing: Picochlorum oklahomense and Picochlorum eukaryotum , both showing 100% sequence similarity to reference taxa. Growth kinetics, biomass productivity, and biochemical composition were assessed. P. oklahomense demonstrated the highest biomass productivity (0.039 mg/L/day), along with a favorable biochemical profile (52.3% protein, 23% carbohydrate) and superior cultivation resilience. A third strain, tentatively identified as Picochlorum sp., exhibited lower but still significant nutritional values (42.3% protein, 20% carbohydrate), suggesting potential for use in animal feed. These results highlight P. oklahomense as a promising candidate for biotechnological exploitation. However, further taxonomic confirmation using multilocus phylogenetic markers is recommended to validate its identification