Mixotrophic Growth of Microalgae Chlorella and Scenedesmus Using Crude Glycerol As Carbon Source

There is a growing global interest in production of ‘green’ fuels that utilize existing infrastructure due to their economical and environmental advantages. This in turn has prompted research activities in production of diesel fuel from algae. In this study, growth rates of two algae strains, Scenedesmus Obliquus and Chlorella Vulgaris, were monitored at 25 ºC and a 14:10 hours light/dark cycle using fluorescent light. Samples of these strains were cultivated under mixotrophic condition with glucose, glycerol and crude glycerol as main carbon sources. All samples were aerated with 3% CO2-enriched air throughout the experiments and shaken daily. The biomass accumulation was measured after 8 and 14 days. Results indicate that the biomass productivity with crude glycerol as the main carbon source compares well with those in glucose and pure glycerol. The highest biomass obtained was 2.480 g/L for Scenedesmus in crude glycerol after 14 days. This study indicates that crude glycerol, a wasted byproduct of biodiesel production from crop oils via transesterification, could be employed to grow Scenedesmus Obliquus and Chlorella Vulgaris.