Fig. 2

a FPKM value of 10 top strongly transcribed genes of G. oxydans 621H. b Strength of screened promoters evaluated with eGFP as reporter and the microscope pictures of P₀₂₈₀₅, P₀₉₄₀₀, P₀₄₆₅₀ and P₁₂₇₈₀. c Relative activity of SpEH. SpEH were expressed with screened and reported promoters. The enzyme activity of SpEH controlled by P_lac was set to 100% and its enzyme activity was 5.69 ± 0.26 U/mL. ****P < 0.0001. d SDS–PAGE of SpEH expression strains with the screened promoters. Lane M: protein marker; Lane 1: whole cell protein of G. oxydans 621H without overexpressing SpEH; Lanes 2–11: whole cell protein of recombinant G. oxydans strains with SpEH expressed by P_lac, P_dnak, P_tufB, P₁₂₇₈₀, P₀₄₀₀₀, P₀₄₇₅₀, P₁₀₁₉₀, P₀₉₄₀₀, P₀₂₈₀₅, P₀₄₆₅₀. e Biotransformation time course of styrene oxide to R-MA of WT-speh and WT-control-speh cells. f Growth curves for G. oxydans 621H under 0, 1, 2, 3 and 4 g/L R-MA