Optimizing light regimes on growth and lipid accumulation in Ankistrodesmus fusiformis H1 for biodiesel production

• 4.47 mM urea concentration was benefit for lipid production in culture.
• Growth and lipid accumulation were detected under different light regimes.
• Inoculum density of OD680-0.5, 18L:6D, 200 μmol m−2 s−1 light regimes were optimized.
• Physiology changes under the optimized culture strategy was investigated.
• Lipid productivity of 116.88 mg L−1 d−1 and 57.58% NL in total lipid were achieved.

The aim of this study was to optimize the light regimes including initial inoculum density, photoperiod and light intensity on the growth and lipid (TAG) accumulation in Ankistrodesmus fusiformis H1 for biodiesel production. At last, the strategy of 4.47 mM urea with initial OD680-0.5, 18:6 h light/dark cycle and 200 μmol photon m−2 s−1 regimes were optimized. The lipid productivity of 116.88 mg L−1 d−1 and 57.58% neutral lipid in total lipid were achieved finally. Moreover, the changes of photosynthetic activity, pigments contents and biochemical compositions revealed that more carbon flow to lipid synthesis. Therefore, A. fusiformis H1 is an ideal candidate for biodiesel production by utilizing light appropriately.