Production of biodiesel from the locally isolated yellow strain of Chlorella sp. using dairy wastewater as a growth medium

Fossil fuels have served humans well for a long time. However, they remain exhaustible and contribute to pollution. Microalgae seem to be an alternative to fossil fuels through biofuel production. These microscopic plants have the opportunity to be grown in different ways to produce biofuel. The aim of this study was to isolate the indigenous unicellular microalgae for their potential of biodiesel production by characterizing their ability to grow in wastewater from dairy effluents under heterotrophic condition. Thus, a local wild yellow strain of Chlorella isolated in oases of Metlili (Algerian Septentrional Sahara) were screened for biomass and lipid production. The results showed that the use of dairy wastewater can replace using of a synthetic medium such as BG11 for the cultivation of the fresh water algae. The addition of nitrogen and magnesium to the dairy wastewater increased significantly the productivity in terms of biomass and lipids. The biomass productivity reached 0.0367 g/h, whereas the productivity inside the BG11 medium was 0.33 g/h. The investigation of lipid production showed high potential for the wild yellow strain to produce biodiesel. Thus, total lipid rate recorded for Chlorella sp. during normal nutrition on dairy wastewater supplemented with nitrogen and magnesium exceeds on average 27% of the algal biomass produced at the decline growth.