ObjectiveTo study the efficient expression conditions, purification, and partial enzymatic properties of His-tagged recombinant Candida utilis uricase.MethodsThe effects of isopropyl β-D-1-thiogalactopyranoside (IPTG) and lactose as inducers which were added in the end logarithmic phase were compared by the method of shake flask culture. The induction culturing time was studied with 50 L fermentor. The protein of interest was purified by Ni-Sepharose and Sephacryl S-200 HR chromatographies, and the optimal pH value, temperature, and thermal stability were also studied.ResultsThe shake flask culturing experiment results showed that IPTG was better than lactose as an inducer. In the fermentor culturing and at the end of the logarithmic growth stage, the enzyme activity of 164 U per gram bacteria and biomass of 23 grams per litter fermented solution were maximal after adding lactose for 7 hours as an inducer, i.e. the enzyme activity could be collected at 3 772 U per liter. The specific activity of purified uricase was 4.5 U/mg and the optimal pH value and temperature were 7.5 and 40℃. Additionally, the enzyme was stable at pH 6.0–10.0 and the thermal stability was below 45℃.ConclusionsIt is better to use lactose as an inducer in the process of culture. The recombinant uricase with His label can be purified by Ni-column affinity chromatography and Sephacryl S-200HR molecular sieve chromatography, and the purification process is easier than ever before. The optimum temperature, pH value, acid-base stability and thermal stability of the purified enzyme have been established to provide some experimental basis for the relationship between structure and function and practical application in the future.