In 250ml triangular flasks filled with 50ml medium, which contains beef paste 1%, peptone 1%, yeast paste 0.5%, NaCl 0.5%, pH 7.0, sterilized at 118 for 30min, cooled to access the Pseudomonas aeruginosa QD96, incubated at 30 oscillation (200r/min) culture for 16h, will be the culture solution by 4000r/min freezing centrifugation The culture solution was frozen and centrifuged at 4000r/min for 30min, then washed with 0.05mol/L phosphate buffer (pH7.0) and centrifuged again, and the resultant organisms were kept refrigerated as nucleotide phosphorylase for spare parts.
In a 100 ml round bottom flask, loaded with 50 ml of substrate solution containing guanosine and thymidine concentration of 40 mol/L, phosphate buffer for 25 mmol/L, the amount of bacterial body added to 5% (wet weight), stirring reaction at 60 in a constant temperature water bath for 2h, the reaction was completed, frozen centrifugation to remove the bacterial body and a small amount of thymine precipitates. Then the solution was detected by HPLC which contained 24 mmol/L deoxyguanosine with a conversion rate of 60%. After separation by anion exchange resin, 0.26 g of deoxyguanosine was obtained.
