Pilot-scale fermentation of rhNDPK-A producing E. coli in 50L culture
50L规模中试发酵重组核苷二磷酸激酶A工程菌

Production of recombinant human nucleoside diphosphate kinase A (rhNDPK-A) in pilot-scale. The primary seed culture was flask-shaked to 5.0~5.5 OD600, and then inoculated into 7L fermentor in ratio of 10%. Cultured to 9.6~10.5 OD600, the secondary seed culture was inoculated into 80L fermentor to carry out fed-batch culture. The obtained bacteria were homogenized under high-pressure and micro-filtered to remove the bacteria residue. Concentrated by superfilter, the crude rhNDPK-A was purified by ion-exchange and affinity chromatography. The results showed that the wet cell yield was 31.27g/L or 1560g/batch in 50L culture after 10h fermentation. The expression level of NDPK-A was 23.8%. In addition, the nutrition fed had significant effect on the density of culture. Compared with only carbon-material feeding, the density of culture was significantly enhanced in the condition of feeding carbon and nitrogen materials, but the expression level had not significant enhancement. In an optimum condition, the culture density was (38.30±0.28) OD600 U/mL; the wet cell yield was (2220.00±169.71)g/batch, i.e. (44.4±x3.4) g/L; the protein level was (22.00±0.42)%. Production of rhNDPK-A in pilot-scale provides materials for the basic research and new drug development of NDPK-A.