Production of polyhydroxyalkanoates from polyols

A system for making polyhydroxyalkanoates comprising an organism genetically engineered to express enzymes selected from the group consisting of a diol oxidoreductase, aldehyde dehydrogenase, acyl-CoA transferase, acyl-CoA synthetase, β-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase,

• wherein the organism can convert diols into hydroxyalkanoate monomers which are polymerized to form polyhydroxyalkanoates.

A composition comprising a polyhydroxyalkanoate copolymer which includes

• 2-hydroxypropionate or 2-hydroxyethanoate or both, and
• at least one comonomer selected from the group consisting of 3-hydroxybutyrate, 4-hydroxybutyrate, 3-hydroxypropionate, 2-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, 6-hydroxyhexanoate, and 3-hydroxyhexanoate, having a weight-average molecular weight (Mw) of at least 300,000.

The composition of example 11 where the comonomer is 3-hydroxybutyrate.

The composition of example 11 where the comonomer is 4-hydroxybutyrate.

The composition of example 11 where the comonomer is 3-hydroxypropionate.

The composition of example 11 where the comonomer is 2-hydroxybutyrate.

The composition of example 11 where the comonomer is 4-hydroxyvalerate.

The composition of example 11 where the comonomer is 5-hydroxyvalerate.

The composition of example 11 where the comonomer is 6-hydroxyhexanoate.

The composition of example 11 where the comonomer is 3-hydroxyhexanoate.

A method for improving a biological system for making polyhydroxyalkanoates with an organism genetically engineered to express enzymes selected from the group consisting of a diol oxidoreductase, aldehyde dehydrogenase, acyl-CoA transferase, acyl-CoA synthetase, β-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase, wherein the organism can convert diols into hydroxyalkanoate monomers which are polymerized to form polyhydroxyalkanoates, the method comprising selecting for mutants with increased enzyme activities by

• i) introducing mutations into a specific host, and
• ii) screening pools of the mutants generated for increased ability to synthesize PHA from a selected diol or diols.

A DNA fragment encoding a diol oxidoreductase and an aldehyde dehydrogenase, wherein the expressed enzymes can produce hydroxyalkanoate monomer selected from the group consisting of 3-hydroxybutyrate, 4-hydroxybutyrate, 3-hydroxypropionate, 2-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, 6-hydroxyhexanoate, 3-hydroxyhexanoate, 2-hydroxypropionate, and 2-hydroxyethanoate from diol.