The optimization of serum-free medium for the production of the scu-PA by the addition of algal extracts.

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