The effect of different trophic modes on lipid accumulation of Scenedesmus quadricauda

In this study, the effects of different carbon sources on cell growth and lipid accumulation of Scenedesmus quadricauda were investigated. Results showed that S. quadricauda could grow on photoautotrophic, heterotrophic and mixotrophic modes. The lipid yield of S. quadricauda was much lower in the culture containing NaHCO3 as only carbon source, while CO2 and glucose concentration significantly influenced cell yield and lipid accumulation in photoautotrophic and heterotrophic culture, respectively. Furthermore, lipid content of S. quadricauda in mixotrophic culture (33.1% of cell dry weight) was much higher than that in photoautotrophic and heterotrophic cultivation (14–28%). Therefore, upon comparing these three trophic modes, present results revealed mixotrophy was the optimal culture method for S. quadricauda to produce lipid. Besides, it was a feasible and promising strategy to culture S. quadricauda using starch wastewater as raw material, which could reduce chemical oxygen demand (COD) of wastewater and the cost of biodiesel production.