OPTIMIZING EXPRESSION CONDITIONS OF ENGINEERED ESCHERICHIA COLI BEARING HUMANIZED ANTI-HBsAG Fab ON LABORATORY SCALE / 解放军医学杂志

ABSTRACT

Objective To investigate the best fermentation and induction models of the engineered Escherichia coli, in order to obtain the highest expression level of humanized anti HBsAg Fab. Methods The optimal condition governing the growth of the Escherichia coli, with the flask shaking method and the best fermentation and induction conditions to yield the highest production level were explored, and then E coli were grown in fermentor using the fed batch method following the same principle under flask shaking condition to ensure the best production. Results The data obtained from flask shaking conditions showed that when the induction procedure started the amount of anti HBsAg Fab would reach the highest level at mid log growth phase under the induction condition of 25℃ and 0 2% arabinose. Using the DO stat fed batch method, the OD 600 value of the culture would reach 55 2, which corresponded to 110g/L bacterial wet weight. The biological activity of Fab was proved to have well preserved. Conclusion We established the optimal production technic of HBsAg Fab, and lay a foundation to produce HBsAg Fab on a large scale