Nodal explants with lateral buds and leaf-derived suspension cultures of sweet basil, Ocimum basilicum L., were cultured in 5 l airlift bioreactors for three weeks, thereby increasing the fresh wt of suspension cultures 2.5-fold. Rosmarinic acid accumulated at 29 micromicrog g(-1) dry wt in the suspension culture but, for micropropagated plants, it reached 178 microg g(-1) dry wt.