Fig. 2

Combinatorial optimisation of the coniferyl alcohol biosynthesis pathway. A The pathway converting ferulic acid into coniferyl alcohol involves three genes – SrCAR, Sfp, and MsCAD2. A combinatorial library of plasmids was designed to encode this pathway, with variations in the origin of replication, order of pathway genes, and promoter parts. B Pathway variants that were tested for the in vivo production of coniferyl alcohol. E. coli NEB5α carrying the individual plasmids were grown at 30℃ for 20 h in TBP medium supplemented with 0.4% glycerol and 3 mM ferulic acid. Error bars represent standard deviations of three biological replicates. Cells were grown in the absence (−) and presence (+) of IPTG