Comparison of photoautotrophic and photoheterotrophic cultivation of Chlorella vulgaris as a suitable source for biodiesel production

With the rapidly dwindling fossil fuel reserves and the world's growing demand for energy, production of biofuels and especially biodiesel has attracted a high attention in recent years. Among different feedstocks for biodiesel production, microalgae that are rich in lipid content and can grow rapidly can be a mighty valued candidate for biodiesel production. Lipid productivity of microalgae depends heavily on the method of cultivation and carbon source. In this study, feasibility of using different concentrations of waste molasses as a cheap carbon source for photoheterotrophic growth of Chlorella vulgaris was investigated and also the results were compared with photoautotrophic growth using sodium bicarbonate. C. vulgaris preferred to grow under photoheterotrophic growth. Results showed that, increase in molasses concentration from 1 to 10 g/l caused more lipid content (6-16%) and productivity (5-26 g/l.d). In contrast, higher concentrations of bicarbonate, more than 4 g/l caused lower lipid content (4.4-3%) and productivity (4-2.15 g/l.d). In fact, high concentrations of bicarbonate result in high pH in the broth, thereby causing inhibitory effects with regard to the microalgae growth

کلیدواژه ها:

Biodiesel ، Chlorella vulgaris ، waste molasses ، cultivation condition