Résumé : A Taxus baccata cell line has been characterized for growth, nutrient uptake, taxane production and for GGPP synthase activity. The enzyme is extracted by inclusion of non-ionic detergent and its activity parallels taxane production for the first three days. The enzyme activity reaches its peak at day 3 of culture growth, while total taxane formation rises until day 9, when the maximum taxane accumulation in the cells is observed (~0.004% dry wt). After this day the taxane excretion in the medium increases, reaching its maximum at day 19.