5. Discussion
This topic focuses on the promotion of the addition of rGO-TiO2 nanoparticles on the growth of FACHB-314platensis and the accumulation of intracellular phycocyanin. Through a series of experimental optimization and exploration, the following conclusions are drawn:
In this experiment, we designed and prepared reduced graphene oxide titanium dioxide nanoparticles (rGO-TiO2) with good biocompatibility, which were used in the cultivation of FACHB-314platensis to enhance the absorption and utilization of light, compared with conventional TiO2 Nanoparticles, rGO-TiO2 nanoparticles have high biocompatibility, have no significant inhibitory effect on the growth of FACHB-314 , and have no obvious damage to the morphology and structure. To study the effects of rGO-TiO2 nanoparticles on the growth ofA. platensis and the accumulation of phycocyanin under different irradiation light colors, light-dark cycles, and light intensity conditions.
Under the same conditions, compared with the TiO2nanoparticles and the control group, the addition of rGO-TiO2 showed a greater promotion advantage. By the seventh day of culture, the maximum phycocyanin content was 80.3 mg/g, and the intracellular phycocyanin production at 97.16 mg/L, the production of phycocyanin increased by 18.7%. Compared with theFACHB-314 cultured with TiO2 nanoparticles, the phycocyanin content increased by 24.6 mg/g compared with the experimental group with TiO2 nanoparticles, and the content increased by 44.2%. On the ninth day of culture, the cell dry weight reached the maximum value of 1.66 g/L, and TiO2was 0.65 g/L.
We found that in the choice of different wavelengths, the cell growth ofA. platensis FACHB-314 and the accumulation of phycocyanin are more biased towards the white light. Under different light-dark cycles, full light has a more obvious promotion effect on the cell growth of A. platensis and the accumulation of phycocyanin. Under different light intensities, we found that high light intensity is more beneficial to the growth of FACHB-314 , while the accumulation of phycocyanin prefers low light intensity. Compared with the control group cultured without nanoparticles, A. platensis FACHB-314doped with rGO-TiO2 nanoparticles can promote the accumulation of phycocyanin.