HIGH CELL-DENSITY CULTIVATION AND HIGH RECOMBINANT PROTEIN-PRODUCTIONOF ESCHERICHIA-COLI STRAIN EXPRESSING URICASE

Uricase from Cellulomonas flavigena SK-4 is an industrially useful enz yme for commercial formulations of hair coloring, The uricase producti on by recombinant Escherichia coli strain with a high cell density cul tivation technique was described, Of three kinds of media, synthetic m edia with the feeding of a high concentration of glucose solution were suitable for high cell density cultivation, As for feeding, both biom ass concentration and uricase productivity were increased by about two (61.2 g dry cell weight (DCW)/liter) and three times (1037 U/ml broth ), respectively, in 24 h by continuous supply, In the case of feeding by a DO-stat method, however, cell concentration was comparable to con tinuous glucose supply but uricase activity was reduced, By supplying pure oxygen to compensate for oxygen limitation during cultivation, th e highest values of 77.4 g DCW/liter and 1113 U/ml broth of the uricas e activity were achieved with the total cultivation time of 15 h.