The present invention relates to the metabolic engineering of a microbial host for the synthesis of value-added products from oil palm empty fruit brunches (OPEFBs). In one embodiment, the genetically engineered microorganism is Escherichia coli comprising a metabolic pathway consisting of 9 enzymes (11 genes) to utilize depolymerized lignin, namely vanillin, p-coumaric acid, p-hydroxybenzaldehyde, vanillic acid, p-hydroxybenzoic acid and ferulic acid, to produce β-ketoadipic acid, which can be subsequently converted into commercially important derivatives such as adipic acid and levulinic acid. The enzymes are feruloyl-CoA synthetase (fcs), enoyl-CoA hydratase (ech), vanillin dehydrogenase (vdh), vanillate O-demethylase (vanA; vanA and vanB), p-hydroxy benzoate hydroxylase (pobA), protocatechuate 3,4-dioxygenase {pcaGH; pcaG and pcaH), 3-carboxy-cis, cis-muconate cycloisomerase (pcaB), 4-carboxymuconolactone decarboxylase (pcaC), and β-ketoadipate enol-lactone hydrolase (pcaD).

The present disclosure provides engineered bacteria for producing vanillin.

The present invention discloses mutant strains of Amycolatopsis sp. ATCC 39116 suitable for the production of natural vanillin using ferulic acid as a feedstock. More specifically, the present invention discloses mutant strains having mutations that reduce the degradation of vanillin to vanillic acid.

The present invention is concerned with methods for producing vanillin, feroyl-CoA, ferulic acid, coniferyl aldehyde and/or coniferyl alcohol. Also, the invention relates to microorganisms useful in such production method, and to the construction of such microorganisms.