As colchicine is toxic to the microorganism, at the initial stage of adaptation,0.1 g/l colchicine was used as selective force. Aqueous solution of colchicine was used to discharge the substrate in the culture broth, after24 h of inoculation. As thiocolchicine is less soluble in aqueous medium,70% ethyl alcohol was used to prepare thiocolchicine solution and mixed in
culture broth on the basis of experiment designed and requirement. Under such conditions the microbes were grown for more than 10 generations till the specific growth rate was obtained same as in control. At the end of each generation the microbes were examined for its ability for biotransformation of colchicine and thiocolchicine to their respective 3-demethyl and glycosyl
derivatives using thin-layer chromatography, and high pressure liquid chromatography. The above practice was continued with gradually increasing in selective force of colchicine up to 10 g/l.