Construction of Catalase Deficient Escherichia coli Strains for the Production of Uricase

Abstract

To produce catalase-free uricase preparations, we constructed catalase-deficient strains from Escherichai coli MC1000 and MM294 and used them as recombinant host strain. The parent strains and catalase-deficient strains showed no differences in the growth characteristics by shaking culture in Erlenmeyer flasks. The catalase deficient strain derived from MC1000 transformed with the uricase expression plasmid pUT118 (strain SN0037) had growth characteristics and the uricase productivity comparable to those of the parent host strain MC1000 in fed-batch culture in a jar fermentor and no catalase activity was detected in cell-free extracts. However, the katG disrupted strains from MM294 carrying pUT118 had poor growth and their uricase productivities were low compared to those of the parent strain MM294. Using the strain SN0037, a catalase-free uricase preparation was obtained with fewer purification procedures and the final recovery of uricase activity was improved. The catalase-deficient E. coli host strain will be a suitable host for the production of the uricase, free of catalase activity, in high yield.