Isolation, Identification, and Evaluation of the Lipid Content of Desmodesmus communis from the Ecuadorian Amazon

The aim of this study was to evaluate biomass generation and determine the total lipid content of a microalgae isolated from a lagoon of the Ecuadorian Amazon. The morphological identification of the isolated microalgae was done through bibliographic comparisons and molecular identification by PCR followed by DNA sequencing and phylogenetic analysis. A 10-day batch culture was operated in 1-L glass bottles, and nutrient removal was determined daily. After harvesting, biomass was centrifuged to remove most of the water content. Half of the obtained biomass was kept wet and the other half was dried for further analysis. Cell growth, optical density, and dry weight were measured during cultivation time. In addition, total lipid and free fatty acid (FFA) percentages were evaluated. Removal of chemical oxygen demand (COD), nitrates (NO 3 − ), and phosphates (PO 4 3− ) was 33.12%, 67.77%, and 76.73%, respectively. The biomass concentration was 2.19 ± 0.12 g/L with a productivity of 0.22 g/L per day. The best extraction percentages of total lipids and FFA were 18.43% and 61.46%, respectively. Although the results of lipids and FFA do not reach the required limits, the productivity of biomass and lipids is comparable with species that are cultivated for biodiesel production.