Effect of Endophytic Fungus Culture Broth on the Growth and Paclitaxel Accumulation of Taxus cuspidata Cells

To investigate the ability of endophytic fungus culture broth (EFCB) to improve paclitaxel release from cultured cells, EFCB was prepared from Fusarium mairei cultured in B₅ medium. Suspension cultures of Taxus cuspidata cells were treated with 2, 4 and 6 mL EFCB at different cultivation stages (days 5, 10 and 15). Cells treated with 4 mL EFCB showed the highest paclitaxel yield (5.88 mg·L⁻¹) and release ratio (67%), 1.9 and 5.6 times higher, respectively, than that of untreated control cells. In terms of timing of the addition of EFCB, the most desirable paclitaxel production (6.1 mg·L⁻¹) and release ratio (75%) were 2 and 6.8 times, respectively, higher than that of control cells, with 4 mL EFCB added to cultures on day 5 of cultivation. Compared with other elicitors, EFCB, at 4 mL, did not damage the plant cell membrane, although it promoted the paclitaxel release capability of plant cells, which suggests that EFCB can activate the related enzymes involved in paclitaxel transport in T. cuspidata cells.