INFLUENCE OF THE CARBON SOURCE ON GROWTH AND ROSMARINIC ACID PRODUCTION IN SUSPENSION-CULTURES OF COLEUS-BLUMEI

Suspension cultures of Coleus blumei were characterized with respect t o growth and rosmarinic acid formation in media with different sugars and various sugar concentrations. Sucrose is the sugar with the highes t stimulating effect on growth and rosmarinic acid accumulation, follo wed by glucose and fructose. The sugar alcohol mannitol cannot be meta bolized by the plant cells. Sucrose is cleaved into glucose and fructo se by the Coleus cells. Sucrose concentrations from 1 to 5% have an in creasing positive effect on growth and rosmarinic acid synthesis in th e cell cultures with a maximum rosmarinic acid content of 12% of the d ry weight in medium with 5% sucrose; in medium with 6% sucrose rosmari nic acid accumulation obviously did not reach its highest level in the culture period of 14 days. A very high yield of rosmarinic acid (2 mg ml-1 suspension) could also be achieved by maintaining a sucrose conc entration of 2% during the whole culture period. The start of rosmarin ic acid synthesis by the cell cultures seems to be regulated by the gr owth limitation when a nutrient, e.g. phosphate is depleted from the m edium. The rate of rosmarinic acid accumulation is related to the amou nt of carbon left in the medium when growth ceases.