Taxus Cell Suspension Culture And Development Of Fermentation Equipment

Plant cell suspension for the production of taxol is a promising technology.However,the large-scale application of this technique always encounters difficulties with online process control due to slow cell growth rate,variability and intense sensitivity to environment factors during cultivation.In this paper,the factors that influence cell growth rate and production variability was investigated.From the cultivation of taxus callus to suspension culture in different bioreactors,pH,working volume,shear force,amino acid,conductivity,inoculums size and sugar concentration were studied to improve cell growth rate.Inoculums size controlled at 4?5g/L and improving the combination of flow field were found to enhance the ability of cell growth,while other factors can not improve the growth rate and some of that even inhibit cell growth.The concentration of elicitors(Ag+,methyl jasmonate,cyclodextrin)according to the real-time biomass was optimized to control the stability of production yielding in different batches.When concentration of elicitors was set at 8?mol Ag+/g(dry cell weight),6?mol MeJA/g(dry cell weight),10 ?mol cyclodextrin/g(dry cell weight),respectively,the yield of taxol can be increased and controlled effectively.In addition,the conductivity feedback controlling strategy was used during the cultivation in stirred tank reactors.When it is controlled at 2.6mS/cm,the cell growth rate and the taxol production rate reached 0.87 g/day and 6.15 mg/g(dry cell),respectively.Moreover,In the process of cryopreservation,taxus callus can be preserved at 4 ? in none-phosphorus medium for couple months and can be supplied to avoid genetic deterioration after multiple subcultures.In conclusion,the results of this paper optimized the cultivated condition in plant cell suspension culture and established optimized process using feedback controlling strategy.It has provided theoretical basis for the scale up of taxol production by taxus cell suspension cultivation,and also made favorable attempts in the high-yield taxus cell cryopreservation.