| In order to choose the best type of airlift bioreactors for the culture of the adventitious root of S.miltiorrhzia, one sphere airlift bioreactor, two modified sphere airlift bioreactors, and one column bubble airlift bioreactor are designed in this work. The flow characteristics such as the gas holdup are investigated first to understand the air distributions in these bioreactors. The final biomass of the different bioreactor is measured and the contents of tanshinonⅡA and protocatechuic aldehyde are also measured with HPLC. The gas holdup of a bioreactor is mensurated in order. The results are as follows:It is found that the air distribution is uniformity and higher gas holdup can be obtained at low flow rate of air in sphere and modified sphere bioreactors, which is better for the culthure of the adventitious root of S.miltiorrhzia. After 20 days'culture, the multiplication of adventitious root in the first (sphere) bioreactor is 2.37, it is higher than that in the second (modified sphere) bioreactor and that in the fourth (column) bioreactor which is 1.64 and 0.73, respectively, less than that in the flask which is 4.05. The content of tanshinonⅡA of adventitious root in the four bioreactors is 0.025 mg·g-1, 0.067 mg·g-1, 0.048 mg·g-1 and 0.021 mg·g-1, respectively, and the content in the sphere bioreactor and in the column bioreactor are lower than that in the flask that is 0.033 mg·g-1. The value in the modified sphere bioreactor is the higest. The content of protocatechuic aldehyde in the second (modified) bioreactor is 0.32 mg·g-1. The content in the second one (modified sphere), that in the fourth (column) bioreactor and that in the flask that is 0.09 mg·g-1, 0.08 mg·g-1and 0.12mg·g-1, respectively. The culture process with different culture time is also investigated. It is reasonable that the modified sphere airlift bioreactor is the best one for the culture of the adventitious root of S.miltiorrhzia from the experimental investigations of this thesis.
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