A TEMPERATURE PROFILE IN BATCH CULTURE TO INCREASE THE PRODUCTION OF THE RECOMBINANT UDP-GLUCURONOSYLTRANSFERASE 2B4 IN ESCHERICHIA-COLI

A cDNA encoding human liver UDP-glucuronosyltransferase 2B4, which glu curonidates the bile acid hyodeoxycholic acid, has been expressed in E scherichia coli as a fusion protein with Staphylococcus aureus protein A. The expression of this protein, under the control of the thermo-in ducible lambda-P-R promoter was induced by a shift in culture temperat ure. In order to increase both the biomass and the amount of recombina nt protein, the temperature profile in the batch culture and especiall y the influence of the time of induction have been studied A lag phase of 35 degrees C, followed by exponential and stationary phases of 42 and 28 degrees C respectively, allowed an increase of about 27% of UGT 2B4 per litre of culture compared to the typical 28-42 degrees C late induced batch culture.