Impact of Nutrient Conditions on Growth and Lipid Accumulation in Scenedesmus obliquus and Chlorococcum humicola as Biofuel Sources

Abstract

This investigation utilizes two indigenous microalgal Species, Scendesmus obliquus and Chlorococcum humicola, to evaluate their lipid production capabilities as a potential biodiesel source under nutrient deprivation conditions, specifically nitrogen limitation at 50% (-N), phosphorus limitation at 50% (-P) and a combination of nitrogen and phosphorus starvation at 50% (-N) 50% (-P). The results indicated that lipid accumulation in Scendesmus obliquus was significantly more effective than that observed in Chlorococcum humicola at (-N50%), with a lipid content of 42.9% of dry weight, in contrast to a minimal lipid content of 15.7% observed in the control, and lipid accumulation in Chlorococcum humicola at (-N) 50% reached to 38.9% of dry weight compared with the control's 12.5% of dry weight. Furthermore, carbohydrate content elevated from 16% in the control to 41% at (-N) 50% + (-P) 50% treatment in Scendesmus obliquus, whereas the highest protein content recorded was 34% of dry weight in the control condition. In the case of Chlorococcum humicola, carbohydrate content was 40.5% of dry weight in the 50 % nitrogen deprivation treatment, with the highest protein content recorded being 29.8% of dry weight in the control condition.