The Astaxanthin Synthesis Metabolism Regulation Characteristics Of Astaxanthin High-yield Phaffia Rhodozyma Strain

Astaxanthin,which possess variety of biological activities such as antioxidant,strengthen immunity,anti-tumor,coloring,is widely used in aquaculture,disease prevention and treatment,and cosmetics.The researchment of the mechanism of astaxanthin synthesis in Phaffia rhodozyma is significant to the development of the natural astaxanthin resources.This study is fouced on the metabolism regulation of astaxanthin synthesis by comparison of astaxanthin high-yield strain JMU-MVP14 and the type strain DSM5626(ATCC 24202)l.The main results are as follows:(1)The strain properties of JMU-MVP14 and the different fermentation characteristics contrast of the type strain DSM5626 were studied.The results showed that the strain properties of JMU-MVP14 had a little diffferent with the DSM5626,while the astaxanthin,protein,fatty acids and ergosterol contents were significantly higher than that in the DSM5626,and the cell growth rate and biomass of JMU-MVP14 was significantly lower than that in the DSM5626.(2)Some metabolic control agents,which have effects on astaxanthin synthesis,were selected to study the regulation mechanism of astaxanthin synthesis in JMU-MVP14 and DSM5626.The results showed that the shortage of precursors such as acetyl-CoA and isoprene pyrophosphate(IPP)may the limitation factors of astaxanthin synthesis in JMU-MVP14;deficient precursor and energy lead to low biomass.While for DSM5626,adding astaxanthin precursor and improving the energy have no effect to promote the synthesis of astaxanthin and improve the activity of the carotenogenic enzymes.Adding different concentrations of fluconazole or triclosan at different times lead a different results,i.e.,adding 120 mg/L of fluconazole or 5 mg/L of triclosan had the best effect on promoting the astaxanthin biosynthesis of JMU-MVP14 at 72 h;adding 120 m/L fluconazole or 30 mg/L of triclosan had the best promoting effect on astaxanthin specific productivity at 72 h,but the astaxanthin volumetric productivity was reduced.The combination control showed that different metabolic control agent,which promoted cell growth or improved the astaxanthin specfic productivity,have different influences could n't effectively stack in this researsh.(3)The regulation metabolism of cell material synthesis was researched by adding ergosterol synthetic inhibitor and astaxanthin synthesis inhibitors in JMU-MVP14.Adding 120 m/L fluconazole at 72 h inhibited ergosterol synthesis and promoted the fatty acids and astaxanthin synthesis,while the cell growth and protein had no effect.Added different content of astaxanthin synthesis inhibitors at 24 h showed that: simvastatin inhibited ergosterol and fatty acids synthetic;N-methyl morpholine significantly promoted the growth of cells,but have no effect on the fatty acid,ergosterol and protein;?-ionone significantly inhibited the growth of cell,fatty acid and protein,and caused the decrease of the ergosterol.