ABSTRACT
The Chlorella sorokiniana F31 is a promising lutein producer with high lutein content. Herein, different graphene/TiO2 nanoparticles (NPs) were designed and synthesized by hydrothermal method. Through the UV-vis diffuse reflectance spectra (DRS) analysis, the results showed that RGO-TiO2 NPs can effectively expand visible light absorption compared with TiO2 NPs. Subsequently, the effects of these NPs on light utilization and lutein accumulation of C. sorokiniana F31 were investigated, and the RGO-TiO2 NPs treatment exhibited the higher lutein production and content than that of TiO2 and control group. As the optimal RGO-TiO2 (0.5 wt%) NPs concentration of 50 mg/L and light intensity of 211 µmol/m2/s, the supreme lutein content (15.55 mg/g), production (77.2 mg/L) and productivity (12.87 mg/L/d) were achieved. The performances are higher than most of reported values in previous study, indicated that RGO-TiO2 (0.5 wt%) NPs treatment is a promised strategy to enhance microalgal growth and lutein accumulation.