Methods of using O-methyltransferase for biosynthetic production of pterostilbene

A biosynthetic method of making pterostilbene comprising:

• expressing a 4-coumarate:coenzyme A ligase (4CL) in a cellular system;
• expressing a stilbene synthase (STS) in the cellular system;
• expressing a resveratrol O-methyltransferase (ROMT) in the cellular system;
• feeding p-coumaric acid to the cellular system;
• growing the cellular system in a medium;
• and
• producing pterostilbene,
• wherein the 4-coumarate:coenzyme A ligase is expressed from a gene that has a sequence identity of at least 66% with a 4CL gene comprising the sequence of SEQ ID NO:
• 14,
• wherein the stilbene synthase is expressed from a gene that has a sequence identity of at least 66% with a STS gene comprising the sequence of SEQ ID NO:
• 16,
• wherein the resveratrol O-methyltransferase is expressed from a gene that has a sequence identity of at least 66% with a ROMT gene comprising the sequence of SEQ ID NO:
• 12, and wherein the resveratrol O-methyltransferase expressed is modified at one or more residues in SEQ ID NO:
• 13 selected from the list consisting of residues 167, 174, 258, 261, and a combination thereof, by an alternative amino acid or a modified amino acid, and wherein the modified resveratrol O-methyltransferase exhibits increased activity in converting resveratrol to pterostilbene relative to an unmodified resveratrol O-methyltransferase comprising the sequence of SEQ ID NO:
• 13.