Abstract: | The effects of eight microelements (I–, BO33–, MoO42–, Co2+, Cu2+, Mn2+, Fe2+, Zn2+) on the biosynthesis of camptothecin and the growth of suspension cultures of Camptotheca acuminata were studied. The increase of I– to 25 M l–1, Cu2+ to 1 M l–1, Co2+ to 2 M l–1 and MoO42– to 10 M l–1 in Murashige and Skoog (MS) medium resulted in 1.66, 2.84, 2.53 and 2.04 times higher of camptothecin yield than that in standard MS medium respectively. Combined treatment of I– (25 M l–1), Cu2+ (1 M l–1), Co2+ (2 M l–1) and MoO42– (10 M l–1) lead to improve cell dry weight, camptothecin content, and camptothecin yield to 30.56 g l–1, 0.0299%, and 9.15 mg l–1, respectively, which were 20.2, 208.9 and 273.8% increment respectively when compared with those of control. |