Figure 2

Biosynthetic pathways for the production of diverse aromatic metabolites by combination of heterologous expression modules with the overproduction of intermediates from SHK- and terminal AAA pathways in Escherichia coli. Salvianic acid from HPP: (a) hpaBC (codes for an endogenous hydroxylase) of E. coli and ldh (lactate dehydrogenase) of Lactobacillus pentosus[94]. 2S-pinocembrin from L-PHE and malonyl-CoA: (b) aroF and pheA ^fbr of E. coli; (c) PAL (phenylalanine ammonia lyase) of Rhodotorula glutinis and 4CL (4-coumarate-CoA ligase) of Petroselium crispum; (d) CHS (chalcone synthase) of Petunia x hybrida and CHI (chalcone isomerase) of Medicago sativa; (e) matB and matC (coding for malonate synthetase and malonate carrier protein) of Rhizobium trifolii[98]. δ-tocotrienol (f) via MGGBQ (2-methyl-6-geranylgeranyl-benzoquinol) (g) from HPP and δ-tocopherol via GGPP (geranylgeranylpyrophosphate): ggh (geranylgeranylpyrophosphate reductase) of Synechocystis sp., crtE (geranylgeranylpyrophosphate synthase) of Pantoea ananatis, hpt (homogentisate phytyltransferase) of Synechocystis sp., hpd (p-hydroxyphenylpyruvate dioxygenase) of Pseudomonas putida, vte1 (tocopherol-cyclase) of Arabidopsis thaliana[95], idi (isopentenyl-diphosphate isomerase) and dxs (1-deoxyxylulose-5-phosphate synthase) of E. coli[96]. Caffeic and ferulic acids from L-TYR: (h) TAL (tyrosine ammonia lyase) and Sam5 (4-coumarate hydroxylase) of Saccharothrix espanaensis and COM (caffeic acid methyltransferase) of Arabidopsis thaliana[103]; (i) TAL of R. glutinis and (j) Coum3H (4-coumarate hydroxylase) of S. espanaensis[104]. Resveratrol from L-TYR and malonyl-CoA: (k) TAL of R. glutinis and 4CL of P. crispum; (l) STS (stilbene synthase) of Vitis vinifera; (m) matB and matC of R. trifolii[99]. Deoxyviolacein and violacein from L-TRP: (n) vioABCD genes of Chromobacterium violaceum and (o) vioE of Janthinobacterium lividum[82]. Continuous arrows show unique enzymatic reactions; dashed arrows show several enzymatic reactions. GAP: glyceraldehyde-3-phosphate. c, indicates chromosomal integration. p, indicates plasmid expression module. ^fbr, feedback resistant gene. ^op, codon-optimized gene. ↱, promoter.