Metabolic changes of recombinant Escherichia coli BL21 (DE3) during overexpression of recombinant human interferon beta in HCDC

摘要

The influence of the overexpression of recombinant human interferon beta (rhINF-β) during high cell density cultivation (HCDC) on metabolic characteristics of recombinant E. coli BL21 (DE3) was studied. Fed-batch culture technique was employed to grow the host cell for the production of human interferon beta in pET expression system in a 5L bench-top bioreactor. The final cell density of 42.15 g L-1 and cell growth (OD600nm) of 103.5 were obtained respectively in fed-batch culture experiment. Four hours after the induction, the specific growth rate was decreased. The initial concentration of the glucose, ammonium and phosphate in the TB culture medium were 5.0, 12.0 and 3.12 g L-1respectively. The maximum amount of the produced rhINF-β was 2.8 g L-1after applying the fed-batch cultivation technique. Besides, time profiles of the acetate and lactate production were similar, the acetate concentration (4.91 g L-1) was lower than that of lactate (10.08 g L-1) and the concentrations of both were lower than the inhibitory levels. Moreover, it was shown that the HCDC and overexpression of rhINF-β did not hamper the plasmid stability