Fig. 2.

Already transcription of the recombinant gene causes growth inhibition. Growth properties of E. coli BL21 (DE3) with expression vectors carrying the gene encoding hFGF-2 in shake-flask cultures with a Luria–Bertani (LB) or b defined glucose-supplemented mineral salt medium. Growth of cells carrying the original expression vector with promoter region and with RBS (squares) and the expression vector with promoter region but without RBS in front of the hFGF-2 gene (triangles). c Growth of cells on LB medium carrying the expression vector without promoter region but with RBS (circles) and without promoter region and without RBS (diamonds). d Control cultures of cells without any expression vector growing on LB medium (stars). Full black symbols always correspond to IPTG induced cultures and open gray symbols to cultures where IPTG addition was omitted. The time-point of IPTG addition to a final concentration of 0.5 mM is indicated by an arrow. Data are presented as mean ± SD, n = 4