Fig. 2
3-HP production in engineered M. extorquens AM1. a Maximum 3-HP titer of engineered strains; b effect of Mcr overexpression on cell growth; c comparison of acetyl-CoA pool in engineered strains at the exponential phase. The y axis is the ratio of intracellular acetyl-CoA between the strains of YHP2, YHP3, YHP4, YHP5, YHP6 and YHP7 to the strain YHP1 respectively. The average value for the YHP1 strain was set to 1; d methanol consumption, growth curve and 3-HP degradation at the transition from exponential phase to stationary phase in the YHP7 strain. YHP1 (M. extorquens AM1/pJY80), YHP2 [M. extorquens AM1/pJY80 (P meta1_3616 ::mcr)], YHP3 [M. extorquens AM1/pJY80 (PcoxB::mcr)], YHP4 [M. extorquens AM1/pJY80 (Ptuf::mcr)], YHP5 [M. extorquens AM1/pJY80 (P mxaF ::mcr)], YHP6 [M. extorquens AM1/pJY80 (P mxaF–mxaF ::mcr)], YHP7 [BHBT5/pJY80 (P mxaF ::mcr::Pmeta1_3616::mcr550–1219)]. The data presented for each strain were the mean calculated from three independent biological replicates (***P ≤ 0.001; **P ≤ 0.01; t test)