Production of human recombinant bone morphogenetic protein-2A by high density culture of Escherichia coli with stationary dissolved oxygen fed-batch condition.

The optimization of cultivation condition in 500 ml shake flasks was carried out to produce recombinant human bone morphogenetic protein-2A (BMP-2A) in recombinant Escherichia coli YK537/pDH-B2m, followed by a 5L fermenter batch and condition-controlled fed-batch culture to obtain BMP-2A. The comparison of these two methods indicated that cultivation by keeping dissolved oxygen at 30%-40% and limiting glucose concentration could obtain BMP-2A 2.78 g/L broth, the final cell density was OD600 53 (dry cell weight 21.2 g/L), and expressed BMP-2A was 25% of the total amount of protein in E.coli. The critical fermentation conditions included: (1) keeping appropriate dissolved oxygen concentration in the process; (2) limiting glucose concentration; (3) taking heat induction at the middle-log phase and maintaining 42 degrees C for 4 hours; (4) controlling specific growth rate around 0.3 h-1 in the duration of growth.