Studies On The Microbial Transformation Of Cholesterol To Produce Androst-1,4-dien-3,17-dione

Andrology-4-ene-3,17-dione (4-AD) and androsta-1,4-diene-3,17-dione (ADD) are important intermediate which are widely used in hormonal drug synthesis. As an important initial material, they can synthesize lots of hormonal medicine.In this paper, the microbial transformation of cholesterol to produce androst-1,4-dien-3,17-dione by means of the strain Gordonia J6has been studied, and the results are as follows.Firstly, in order to increase the cholesterol dissolution, several organic solvents such as alcohol, Tween-80were used as solubilizing agents, The result showed that substrates dissolved in Tween-80and following with ultrasonic emulsification was helpful to increase the substrate dissolution and conversion rate. Two-phase water-organic systems was also used to transform cholesterol to produce androsta-1,4-diene-3,17-dione (ADD), the results showed that use of bis(2-ethylhexyl) phthalate as organic phase was found suitable for the above-mentioned biotransformation;Secondly, the conditions of transformation used growing bacterial cell were optimized, they were as follows:the initial pH value is7, temperature is 30℃, and with5%inoculation,5g/L concentration of substrate;At last, the optimal conditions of cholesterol transformation in two-phase system by means of resting cells were investigated, the results showed that using30%DOP as the organic phase, with5g/L substrate concentration, the conversion rate of ADD was improved3times.