THE OPTIMIZATION OF SERUM-FREE MEDIUM FOR THE PRODUCTION OF THE SCU-PA BY THE ADDITION OF ALGAL EXTRACTS

The addition of 2.8 mu g/ml algal extracts enhanced both scu-PA produc tion and cell growth in a serum-free medium, compared to a conventiona l serum-free medium for the cultivation of recombinant CHO cells. The growth rate and scu-PA production were relatively lower in the serum-f ree medium than 5% serum containing medium: however specific scu-PA pr oduction rate was higher in the serum-free medium due to the long-term period of cultivation (3.66 x 10(-4) vs. 2.48 x 10(-4) IU/cell/day). Overall scu-PA production rate was also greater in an enforced serum-f ree medium as 25,000 IU/day over 50 d of perfusion cultivation. The co nversion ratio of scu-PA to tcu-PA was greatly reduced in the serum-fr ee medium during perfusion cultivation (10% compared to 20% conversion in a serum containing medium).