Taxus Cell Suspension Cultures: Optimizing Growth and Production of Taxol

Cell suspension cultures were established from Taxus x media cv. Hicksii callus cultures. Suspension cultures were grown on different concentrations and combinations of sucrose, glucose, and fructose. Sucrose in the culture medium was rapidly hydrolyzed to fructose and glucose. The resulting glucose was utilized at a faster rate, compared to fructose; however, fructose was the sole sugar in the medium during the latter part of the culture period. Fructose, when used as the sole sugar, promoted better cell growth compared to equimolar amounts of glucose and sucrose. Culturing suspension cultures at 12°C slowed the doubling times 3-fold, thereby providing an effective temporary alternative for long-term storage of suspension cultures. High performance liquid chromatographic analysis of cell suspension culture extracts exhibited a putative taxol peak that eluted 15 to 20s after the elution time for authentic taxol. The presence of taxol in the putative taxol peak was established following analysis by fast atom bombardment mass spectrometry using taxol purified from these cell cultures. Although we have established the presence of taxol in the peak represented as the putative taxol peak, the constituents represented by it as well as the amount of taxol contained within it remain unknown.