Methods of preventing or retarding or reversing or abolishing the onset of Parkinson's and other neurodegenerative diseases are discussed.

The present disclosure provides engineered bacteria for producing vanillin.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.

Methods of preventing or retarding or reversing or abolishing the onset of Parkinson's and other neurodegenerative diseases are discussed.

A method for producing an objective substance such as vanillin and vanillic acid is provided. An objective substance is produced from a carbon source or a precursor of the objective substance by using a microorganism having an objective substance-producing ability, which microorganism has been modified to have a Bacteroidetes O-methyltransferase (OMT) gene, especially an OMT gene encoding OMT having a specific mutation.

Described herein is a polypeptide encoding a prenyltransferase for prenylating a polyphenol and a polypeptide encoding an O-methyltransferase for methylating a polyphenol. For example, the polypeptide comprises or consists of the sequence of SEQ ID NO: 1, 2, 3, 4, 5, and/or 6, and/or a polypeptide listed in Table 1, and/or SEQ ID NO: 7-30, or a variant thereof having at least 80% sequence identity to SEQ ID NO: 1, 2, 3, 4, 5, and/or 6, and/or the polypeptide listed in Table 1, and/or SEQ ID NO: 7-30, or a fragment of the polypeptide or the variant thereof.

A method for producing an objective substance such as vanillin and vanillic acid is provided. An objective substance is produced from a carbon source or a precursor of the objective substance by using a microorganism having an objective substance-producing ability, which microorganism has been modified to have a Bacteroidetes O-methyltransferase (OMT) gene, especially an OMT gene encoding OMT having a specific mutation.

Provided herein are genetically modified host cells. compositions. and methods for improved production of vanillin and/or glucovanillin. The host cells. compositions. and methods described herein provide an efficient route for the heterologous production of vanillin and/or glucovanillin and any compound that can be synthesized or biosynthesized from either or both.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to express a mutant AROM polypeptide and/or mutant catechol-O-methyltransferase polypeptide alone or in combination with one or more vanillin biosynthetic enzymes or UDP-glycosyltransferases (UGTs). Such microorganisms, plants, or plant cells can produce vanillin or vanillin beta-D-glucoside.