Fig. 2

The intracellular ¹³C-3PGA (a), cell growth (b), MFI_h-CO2 values (c), and soluble protein expression (d) of BL21(DE3) strains harboring different plasmids. All strains were 1:100 inoculated into LB medium containing 100 mM NaH¹³CO₃ and shaken at 37 °C. When the culture reached the mid-log phase (OD₆₀₀ = 0.4–0.6), 0.02 mM IPTG was added to induce Rubisco expression and the induction temperature was reduced to 22 °C (zero point). The PRK-encoding gene under the control of a tryptophan-regulated promoter trpR-P_trp was leakily expressed in LB medium. RbcL and RbcS are the large and small subunits of Rubisco, which are encoded by rbcL and rbcS genes, respectively. RbcX is the specific chaperon of Rubisco, which is encoded by the rbcX gene. Molecular weight standards from top to bottom are 80, 60, 40, 30, 20, and 12 kDa