Significant improvement of taxane production in suspension cultures of Taxus chinensis by sucrose feeding strategy

The effects of both initial sucrose concentration and sucrose feeding on ce ll growth and accumulation of taxane diterpene (taxuyunnanine C) in suspens ion cultures of Taxus chinensis were investigated in detail. For the initia l sucrose concentrations of 20, 30, 40 and 50 g/l, the cell growth was repr essed by the later two high levels (i.e. 40 and 50 g/l of initial sucrose) with a relatively longer lag phase. Combination of initial low sucrose conc entration (20 g/l) and subsequent sucrose feeding during cultivation (fed-b atch culture) improved the cell growth, and a final cell concentration of o ver 27 g dry cells/l was successfully achieved after 23 days of cultivation . The time course of the taxane formation was related to the cell growth pr ofile. For example, in the cell cultivation with under 30 g/l of initial su crose, the specific taxane production (content) was relatively low when the cells were under active growth, but sharply increased up to similar to 14 mg/g DW when the cells approached the stationary phase. In the batch cultur es with an increase in initial sucrose concentration from 20 to 50 g/l, bot h the taxane content and productivity were decreased. In the fed-batch cult ures, a relatively high taxane content was obtained at the end of cultivati on; both a very high taxane production of 274.4 mg/l and a high productivit y of 9.3 mg/(1 day) were successfully achieved by feeding 20 g/l of sucrose (on day 7) to the cell cultures. (C) 2000 Elsevier Science Ltd. All rights reserved.