LAUSR

Abstract Background Microalgae are microorganisms that produce various products, among others, pigments, mainly carotenoids. This study has the objective of using the strain of Muriellopsis sp. and evaluate their behavior when grown in freshwater and seawater, along with the indoor and outdoor conditions for both. Growth of the strain was evaluated by determining its biomass, lutein productivity by using high performance liquid chromatography (HPLC), and antioxidant activity by using the 2,2-diphenyl-1-picrilhydrazil (DPPH method). Results Muriellopsis sp. strain in indoor cultures showed an increased antioxidant activity. In outdoor conditions, both cultures increased cells number, concentration of biomass, and lutein productivity. The percentage of lutein obtained from the strain MCH in indoor conditions was 25 times higher than that reported for calendula, reaching 0.75% of lutein in Muriellopsis sp. cultured in seawater, followed by 0.6% in Muriellopsis sp., cultures in freshwater, at day 12 of both cultures. These values exceed that of microalgae Scenedesmus almeriensis, which reaches 0.53% lutein. Conclusions The results show that the native strain of the Atacama Desert is one of the largest producers of lutein as compared to those reported so far. Demonstrated the feasibility of producing this carotenoid that has well-known properties to prevent some diseases due to its high nutritional value. Muriellopsis sp. cultivation in open-air seawater is a good precedent for developing mass production of this species in an area where freshwater is scarce and costly.