Fig. 1

Growth inhibition resulting from the production of different recombinant proteins. Production of a, c hFGF-2 and b, d GFP using E. coli BL21 (DE3) as expression host was carried out in a, b Fernbach flasks with baffles and in c, d bioreactor batch cultures employing a defined mineral salt medium with glucose as carbon substrate. a, b OD600 (circles), glucose (squares) and SDS-PAGE analysis of target protein production (S: soluble, and I: insoluble cell protein of control and producing cells, the positions of target proteins are indicated) are shown. c, d Carbon dioxide (CTR, green lines) and oxygen transfer rates (OTR, blue lines) as well as dissolved oxygen concentrations (black and gray lines) are given. The arrows indicate the time point of IPTG addition to a final concentration of 0.25 mM in production experiments. Dark colored symbols and lines correspond to production experiments. Light colored lines and open gray symbols correspond to control experiments where IPTG addition was omitted. Data are presented as mean ± SD, n = 2