Abstract
We sought to make easier the production of uricase (urate: oxygen oxidoreductase, EC 1.7.3.3) and found that this enzyme was rapidly extracted from Candida utilis cells by treatment with a reducing agent plus a surfactant when the culture broth was between pH 7.0 and 10.0. Some nonionic and cationic surfactants were effective in the extraction of uricase. Of the various reducing agents tried, thiol compounds such as 2-mercaptoethanol (2-ME) also increased extraction in the presence of 0.1% Triton N-101. For the extraction of much uricase, the amount of 2-ME needed was 0.02% or more. The maximum extracellular enzyme activity (0.523 U ml−1broth) was obtained with Triton N-101 at 0.1% or more concentration in a broth of pH 8.0 containing 0.1% 2-ME. Between pH 7.0 and 10.0, where uricase was stable, the enzyme was rapidly extracted into the culture broth. The uricase activity obtained by this method was higher than that obtained by conventional methods such as autolysis and sonication, which gave activities of 0.306 and 0.359 U ml−1broth, respectively.