Artemisinin (AN), a potent antimalarial drug that has been used for centuries as a folk remedy in China, is an effective treatment against quinine-resistant strains of Plasmodium. It can be produced through the in vitro culture of genetically transformed (hairy) roots. The effect of gibberellic acid (GA3) on the growth and secondary metabolite production of hairy roots of Artemisia annua was investigated. Six different concentrations of GA 3 were tested in shaker flasks to determine the optimum concentration. GA3 levels of 0.01-0.001 mg/l (28.9-2.89 ~tM) provided the most significant increase in biomass, and 0.01 mg/1 (28.9 laM) produced the highest amount of AN. Investigation of growth kinetics showed that the use of GA 3 at 0.01 mg/1 (28.9 ~tM) increased the growth rate of hairy roots ofA. annua by 24.9%. Thus, the cultures treated with GA s reached stationary phase faster than control cultures.

A nutrient mist bioreactor was modified for culturing transformed roots of Beta vulgaris and Carthamus tinctorius on a nylon support. Culture conditions of misting cycle, inoculum size, batch or continuous operation and sucrose concentration were varied in order to maximize growth over a 1-week period. Root tissue cultured in nutrient mists in a 1.8-1 culture chamber achieved levels of growth equivalent to hairy roots cultured in shake flasks with identical medium. Our resuits demonstrate the effectiveness of nutrient mist culture as applied to hairy roots, thereby providing an alternative means for successful culture of these tissues.

Golgi apparatus were released without fixatives from rat hepatocytes by gentle homogenization, concentrated by differential centrifugation, and purified by sucrose gradient centrifugation. Examination of sections of purified fractions by electron microscopy showed fields of morphologically intact units of Golgi apparatus consisting of stacks of parallel flattened cisternae, secretory vesicles, and small vesicular profiles. Negative staining of unfixed pellets revealed a complex network of anastomotic tubules continuous with platelike structures and secretory vesicles. These structures corresponded, respectively, to the small vesicular profiles and parallel flattened cisternae with attached secretory vesicles of sectioned material. Small fragments of granular endoplasmic reticulum were often closely associated with the peripheral tubules, suggesting sites of continuity in intact hepatocytes.