Berberine production by batch and semi-continuous cultures of immobilized Thalictrum cells in an improved bioreactor.

A new bioreactor (liquid-gas two-phase system) was devised for berberine-secreting Thalictrum minus cells immobilized in calcium alginate beads, which were alternately soaked in medium, and exposed to air. The highest yield of berberine (875 mg/l) was obtained by setting the cycle of medium supply and air supply for 30 seconds and 2 minutes, respectively, during a culture period of 30 days. Under such conditions of batch culture, the berberine productivity of immobilized cells was as high as that of freely suspended cells. Furthermore, the rate of berberine production by immobilized cells remained constant at a high value (50 mg/l/day) for a period of 60 days of semi-continuous culture achieved by renewal of medium at intervals of 10 days.