Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 5   p.396-400

Effects of medium composition on the production of plasmid DNA vector potentially for human gene therapy

XU Zhi-nan^†, SHEN Wen-he, CHEN Hao, CEN Pei-lin

(Institute Bioengineering, School of Material Science and Chemical Engineering, Zhejiang University, Hangzhou 310027, China)
^†E-mail:z znxu@zju.edu.cn
Received Feb. 10, 2004; revision accepted July 8, 2004

Abstract: Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The effects of different MMBL components on plasmid yield, cell mass and specific plasmid DNA productivity were evaluated on shake-flask scale. The results showed that glucose was the optimal carbon source. High plasmid yield (58.3 mg/L) was obtained when 5.0 g/L glucose was added to MMBL. Glycerol could be chosen as a complementary carbon source because of the highest specific plasmid productivity (37.9 mg DNA/g DCW). After tests of different levels of nitrogen source and inorganic phosphate, a modified MMBL medium was formulated for optimal plasmid production. Further study showed that the initial acetate addition (less than 4.0 g/L) in MMBL improved plasmid production significantly, although it inhibited cell growth. The results will be useful for large-scale plasmid production using recombinant E. coli system.

Key words: Plasmid DNA, Growth medium, Gene therapy
doi:10.1631/jzus.2005.B0396             CLC number: Q782