Influence of nutrient deprivations on lipid accumulation in a dominant indigenous microalga Chlorella sp., BUM11008: evaluation for biodiesel production.

Abstract Microalgae are a potential source of biodiesel. The urgent need for an alternative and sustainable energy has created renewed interest to analyze the microalgae for biodiesel production. In this study, a dominant indigenous freshwater unicellular microalgal strain Chlorella sp., BUM11008 , was examined for its efficiency towards biodiesel production. The organism was evaluated for ability to yield high of biomass and lipid productivity under normal and various nutrient-deprived conditions (nitrogen, phosphate-potassium, iron, and all three combined). Under normal conditions, after 20 days of cultivation in Chu10 medium, the organism yielded a biomass of 2.58 ± 0.07 g/L, with lipid content of 312.16 ± 2.38 mg/g. In a two-phase culturing system upon nutrition deprivation, the organism was able to respond with different levels of lipid accumulation. Among the various post-harvest treatments, nitrogen deprivation yielded the highest lipid productivity of 53.96 ± 0.63 mg/L d, followed by the combined deprivation condition (49.16 ± 1.36 mg/L d). FAME profiles of the isolate were found to meet the requirements of international standards for biodiesel. The study leads to the conclusion that the two-phase culturing system with nitrogen starvation as post-harvest treatment would be suitable for gaining maximum biomass productivity, and lipid content of high quality fatty acids. Thus, it is proposed that Chlorella sp., BUM11008 , would be a promising candidate for sustainable biodiesel production.