Cell suspension culture of Rhizoma zedoariae in a two-stage perfusion bioreactor system for β-elemene production

We presented a two-stage combined bioreactor system consisting of a stir-tank and an airlift column, and challenged with Rhizoma zedoariae cell suspensions for beta-elemene production. Two-stage culture was initiated when the cell concentration in both vessels was maintained at an appropriate density. The cells were proliferated in stirred-tank with the maximal growth rate of 0.17d(-1) to present enough cells for beta-elemene synthesis. In the airlift column, continuous cell separation from culture medium was achieved by using a cell retention device based on centrifugal and gravity settling when the system was performed in perfusion mode. The results indicated that additives can efficiently promote the accumulation of beta-elemene in R. zedoariae cells. In addition, the beta-elemene content showed higher levels in cell lines of overexpressing 3-hydroxy-3-methylglutaryl coenzyme-A reductase, Farnesyldi phosphate synthase, and ST02C genes.