Fig. 1

a The pathways of central carbon metabolism, TCA cycle, fatty acid synthesis, and genetic engineering strategy. b The growth curves of transgenic E. coli K12 with different gene sets expression under organic-free medium supplied with 0.5% DMSO, 0.00005% thiamine, H₂ gas, without any amino acid in the presence or absence of CO₂. c Enlarged view of growth curves under organic-free medium in the absence of CO₂. The DNA cassettes used to construct expression plasmids pGETS-K and pGETS-KA which encode genes korA and korB, aclB and aclA form C. tepidum. Data are expressed as means standard ± deviation, n = 3 independent biological samples