TAXOL PRODUCTION IN SUSPENSION-CULTURES OF TAXUS-BACCATA

The response of Taxus baccata (PC2) to basic manipulations of culture conditions is described. Suspension cultures of Taxus baccata (PC2) we re maintained at 25 degrees C on a modified B5 medium with two-week tr ansfers. Under these conditions, no taxol(R) is formed. However, if th e cells are left in the same medium for 7 or more additional days, tax ol is produced and released (ca. 90%) into the extracelluIar medium. L evels as high as 13 mg 1(-1) extracellular taxol were achieved in shak e flask cultures and taxol was the primary taxane formed representing between 50 and 80% of total taxane in the medium. The cells are sensit ive to changes in culture conditions and cultures cycle through period s of high (13 mg 1(-1)) and low (<0.1 mg 1(-1)) levels of taxol produc tion during extended culture. Picloram was the most effective of the a uxins tested with respect to cell growth but it suppressed taxol produ ction. Addition of fructose to moderately-productive cultures (ca. 4 m g 1(-1)) improved taxol production, but cultures in a high producing s tate did not respond. Glucose suppressed taxane production. Two isopre noids (geraniol and pinene) had a modest effect on taxol production wh en added to cultures at 10 mg 1(-1).