Evaluación de carotenoides y lípidos en la microalga Scenedesmus dimorphus a escala laboratorio

Carotenoids are metabolites produced by microalgae that perform as accessory pigments in photosynthesis and as photoprotective molecules. In order to increase the accumulation of carotenoids in the microalga Scenedesmus dimorphus, salinity (NaCl and KNO3) and blue LED light were evaluated as stress factors when reaching the stationary phase of culture growth in such microalga. After evaluation, the bestof the two salts studied was KNO3 0.6M, since this culture reached the highest concentration of total carotenoids (0.3357±0.02 μg carotenoids mL-1), in contrast to 0.1791±0.01 µg mL-1 with NaCl 0.6 M. Subsequently, the process was scaled in an adapted container of 4 L, entering the stationary phase on day 12. On day 14 the KNO3 was added at 0.6 M; this experiment lasted 20 days of cell count, obtaining on the last day a total of 0, 7395±0, 05 μg of carotenoids mL-1 by means of spectrophotometry. Afterwards, drying of the culture with salinity was carried out, obtaining a dry weight of 5.7 g, with a productivity of 0.0927 g L-1d-1. Final- ly, through HPLC CHRomatography, the lipid profile of the culture was analyzed, resulting in 21.1% MUFAS, 35.9% sFAS, and 43% PUFAS (34% omega-6 and 8.9% omega-3). Based on the above, it was determined that salinity is a possible factor to increase in a greater proportion the concentration of lipids than that of ca- rotenoids, specifically in a ratio of 1:2,500 carotenoids and lipids, respectively.