The high cell density cultivation (HCDC) of a recombinant
E. coli producing human growth hormone (hGH)
under different heat induction strategies has been
reported. In this paper the effect of heat shock temperature,
its duration and post-induction temperature, at
two levels on cell growth and death, hGH production
and its degradation, substrate utilization and by-product
formation were investigated by full factorial experimental
design. The results showed that heat shock
temperature was the most effective factor on hGH production
having approximately 75.8% of total contribution.
There was no significant accumulation of substrate
or by-product in culture medium during HCDC in
all experiments. Thirty two percent of cells were subjected
to lysis during the heat induction at 42°C for 20
min followed by 37°C for 4h. Biologically active recombinant
hGH was produced comprising 13% of total cell
protein without degradation. An empirical equation
was employed to describe the relationship between
three factors and hGH production during HCDC.
کلید واژگان :
Heat induction; High cell density culture; Human growth hormone; Recombinant E. coli
