High cell density fermentation of engneering E. coli expressing tumor targeted interferonª²¦Á2a

    MENG Jieª²Ru, YAN Zhen, ZHAO Ning, ZHANG Yingª²Qi

    Biotechnology Centre, Department of Pharmaceutics, Fourth Military Medical University, Xi¡¯an 710033, China

    ¡¾Abstract¡¿ AIM: To optimize the pilotª²scale fermentation procedure of E.coli producing tumor targeted human IFNª²¦Á2a and to obtain high cell density and high level expression of the aim protein. METHODS: The effects of the rang of pH, dissolved oxygen, culture time, induction time and the manner of feeding were analyzed with 10 L of fermentation tank. RESULTS: Under the established conditions, we performed a threeª²time repeated fermentation. The final cell density was A600 nm 25-30 and more than 50 g of wet bacteria per liter could be obtained. The expression level of recombinant protein was higher than 3.2¡Á109 U/L. CONCLUSION: The results show that the established fermentation procedure is stable, of short cycle and with high expression, which lays the basis for further purification and largeª²scale production of IFNª²¦Á2aª²NGR. ......