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).

An aspect of the present disclosure is a microbial cell that includes a genetic modification resulting in the expression of a deficient form of an endogenous dioxygenase, and a gene encoding an exogenous dioxygenase and a promoter sequence, where the endogenous dioxygenase includes PcaH and PcaG, the exogenous dioxygenase includes LigA and LigB, the microbial cell is capable of growth utilizing at least one of a cellulose decomposition molecule or a lignin decomposition molecule, and the microbial cell is capable of producing 2-hydroxy-2H-pyran-4,6-dicarboxylic acid.

An aspect of the present disclosure is a microbial cell that includes a genetic modification resulting in the expression of a deficient form of an endogenous dioxygenase, and a gene encoding an exogenous dioxygenase and a promoter sequence, where the endogenous dioxygenase includes PcaH and PcaG, the exogenous dioxygenase includes LigA and LigB, the microbial cell is capable of growth utilizing at least one of a cellulose decomposition molecule or a lignin decomposition molecule, and the microbial cell is capable of producing 2-hydroxy-2H-pyran-4,6-dicarboxylic acid.

The present invention relates to the fields of life sciences, micro-organisms and degradation of polyolefin polymers. Specifically, the invention relates to an isolated specific enzyme or a fragment thereof, wherein said enzyme or fragment is capable of degrading a polyolefin, and to a micro-organism or a host cell comprising the enzyme or a fragment thereof. Also, the present invention relates to a polynucleotide encoding the enzyme or fragment thereof, and to an expression vector or plasmid comprising the polynucleotide of the present invention. And still, the present invention relates to use of the enzyme, fragment, micro-organism, host cell, polynucleotide, expression vector or plasmid of the present invention for degrading a polyolefin: to a method of degrading a polyolefin with the specific enzyme or a fragment thereof: and to a method of producing the enzyme or fragment thereof of the present invention.

An aspect of the present disclosure is a microbial cell that includes a genetic modification resulting in the expression of a deficient form of an endogenous dioxygenase, and a gene encoding an exogenous dioxygenase and a promoter sequence, where the endogenous dioxygenase includes PcaH and PcaG, the exogenous dioxygenase includes LigA and LigB, the microbial cell is capable of growth utilizing at least one of a cellulose decomposition molecule or a lignin decomposition molecule, and the microbial cell is capable of producing 2-hydroxy-2H-pyran-4,6-dicarboxylic acid.

An aspect of the present disclosure is a microbial cell that includes a genetic modification resulting in the expression of a deficient form of an endogenous dioxygenase, and a gene encoding an exogenous dioxygenase and a promoter sequence, where the endogenous dioxygenase includes PcaH and PcaG, the exogenous dioxygenase includes LigA and LigB, the microbial cell is capable of growth utilizing at least one of a cellulose decomposition molecule or a lignin decomposition molecule, and the microbial cell is capable of producing 2-hydroxy-2H-pyran-4,6-dicarboxylic acid.