The aim of this study was to promote fucoxanthin accumulation in Phaeodactylum tricornutum by photo-fermentation through optimizing the mode of multiple nitrogen supplementation and blue light enhancement.The results showed that the mixed nitrogen source(tryptone∶urea=1∶1,N mol/N mol;total nitrogen concentration at 0.02 mol/L)added to the culture system by six times was the best mode in shake flasks.Two-phase culture with light adjustment was then carried out in 5 L photo-fermenter with an enhanced blue light(R∶G∶B=67.1∶16.7∶16.3)in the second phase,leading to improved cell density(1.12×108cells/mL),biomass productivity(330 mg/(d-L)),fucoxanthin content(19.62 mg/g),titer(69.71 mg/L)and productivity(6.97 mg/(d-L)).Compared with one-phase culture under red/blue(R:G:B=70.9:18.3:10.9)light and six-times nitrogen supplementation,the fucoxanthin content was significantly increased by 7.68％(P＜0.05)but the productivity did not change significantly(P＞0.05).Compared with one-phase culture under red/blue(R∶G∶B=70.9∶18.3∶10.9)light and one-time nitrogen supplementation,the content and productivity of fucoxanthin were significantly increased by 45.98％and 48.30％(P＜0.05),respectively.This study developed a two-phase culture mode with multiple nitrogen supplementation and blue light enhancement,which effectively promoted the accumulation of fucoxanthin and improved the efficiency of nitrogen source utilization,thus providing a new approach for fucoxanthin accumulation in P.tricornutum by photo-fermentation.
维普
万方数据
