Disclosed is a mutant strain having the ability to produce polyhydroxybutyrate. The novel strain has a significantly high growth rate and an improved ability to produce PHB compared to existing PHB-producing cyanobacterial strains. Therefore, the novel strain is suitable for use in the production of PHB and the development of various products using PHB. In addition, the novel strain is useful as a photosynthetic strain for developing a PHB production process using industrial flue gas due to its ability to produce PHB from only CO.sub.2 without any additional organic carbon source. Also disclosed is a method for producing polyhydroxybutyrate using the mutant strain.

The use of microorganisms to make alpha-functionalized chemicals and fuels, (e.g. alpha-functionalized carboxylic acids, alcohols, hydrocarbons, amines, and their beta-, and omega-functionalized derivatives), by utilizing an iterative carbon chain elongation pathway that uses functionalized extender units. The core enzymes in the pathway include thiolase, dehydrogenase, dehydratase and reductase. Native or engineered thiolases catalyze the condensation of either unsubstituted or functionalized acyl-CoA primers with an alpha-functionalized acetyl-CoA as the extender unit to generate alpha-functionalized β-keto acyl-CoA. Dehydrogenase converts alpha-functionalized β-keto acyl-CoA to alpha-functionalized β-hydroxy acyl-CoA. Dehydratase converts alpha-functionalized β-hydroxy acyl-CoA to alpha-functionalized enoyl-CoA. Reductase converts alpha-functionalized enoyl-CoA to alpha-functionalized acyl-CoA. The platform can be operated in an iterative manner (i.e. multiple turns) by using the resulting alpha-functionalized acyl-CoA as primer and the aforementioned alpha-functionalized extender unit in subsequent turns of the cycle. Termination pathways acting on any of the four alpha-functionalized CoA thioester intermediates terminate the platform and generate various alpha-functionalized carboxylic acids, alcohols and amines with different β-reduction degree.

The present disclosure provides microbial organisms having increased availability of co-factors, such as NADPH, for increasing production of various products, including 1,3-BDO, MMA, (3R)-hydroxybutyl (3R)-hydroxybutyrate, amino acids, 3HB-CoA, adipate, caprolactam, 6-ACA, HMD A, or MAA, and products made from any of these. Also provided are one or more exogenous nucleic acids encoding an enzyme expressed in a sufficient amount to increase availability of NADPH, where the exogenous nucleic acid includes one or more of ATP-NADH kinase, pntAB, nadK, and gapN. Also provided are one or more gene attenuations occurring in genes, such as NDH-2, that result in an increased ratio of NADPH to NADH. Various combinations of the exogenous nucleic acids and gene deletions are also provided in the present disclosure. The present disclosure also provides methods of making and using the same, including methods for culturing cells, and for the production of the various products.

The present disclosure provides thiolases and polypeptide variants of 3-hydroxybutyryl-CoA dehydrogenase, nucleic acids encoding the same, vectors comprising the nucleic acids, and cells comprising the polypeptide variants and/or thiolase, the nucleic acids, and/or the vectors. The present disclosure also provides methods of making and using the same, including methods for culturing cells, and for the production of various products, including 3-hydroxybutyryl-CoA (3-HB-CoA), 3-hydroxybutyraldehyde (3-HBal), 3-hydroxybutyrate (3-HB), 1,3-butanediol (1,3-BDO), and esters and amides thereof, and products made from any of these.

Provided are nucleic acids and vectors that collectively encode various gene products related to converting styrene to polyhydroxybutyrate (PHB). In some embodiments, the nucleic acids and vectors collectively encode a styrene monooxygenase polypeptide, a flavin reductase polypeptide, a styrene-oxide isomerase polypeptide, and a phenylacetaldehyde dehydrogenase polypeptide, an acetyl-CoA C-acetyltransferase polypeptide, a 3-ketoacyl-ACP reductase polypeptide, a class I poly(R)-hydroxyalkanoic acid synthase polypeptide, and optionally an influx porin polypeptide. Also provided are systems and methods for producing PHB from styrene, methods and systems for remediating polystyrene waste. In some embodiments, the systems are in vivo systems.

Disclosed is a mutant strain having the ability to produce polyhydroxybutyrate. The novel strain has a significantly high growth rate and an improved ability to produce PHB compared to existing PHB-producing cyanobacterial strains. Therefore, the novel strain is suitable for use in the production of PHB and the development of various products using PHB. In addition, the novel strain is useful as a photosynthetic strain for developing a PHB production process using industrial flue gas due to its ability to produce PHB from only CO.sub.2 without any additional organic carbon source. Also disclosed is a method for producing polyhydroxybutyrate using the mutant strain.

Provided is engineered microorganisms expressing acetoacetyl-CoA reductase variants and a method for improving the yield of PHA. Compared with the wild-type acetoacetyl-CoA reductase represented by SEQ ID NO. 31, the variant has one or more of the following mutations: (1) mutation of valine at position 141 to isoleucine or leucine; (2) mutation of methionine at position 12 to threonine, serine, alanine, leucine, lysine or isoleucine; (3) mutation of isoleucine at position 194 to valine, leucine or methionine; (4) mutation of glutamic acid at position 42 to lysine, glutamine, leucine, aspartic acid, proline, threonine, asparagine, or histidine; and (5) mutation of phenylalanine at position 55 to valine, alanine or isoleucine. The variants and their coding genes can promote the synthesis and accumulation of PHA by the strain and increase the yield of PHA.

The disclosure provides recombinant bacterial host cells that metabolize and convert glycerol or volatile fatty acids (VFAs) to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV. The disclosure further provides methods of producing PHBV using the recombinant bacteria disclosed herein.

The disclosure provides recombinant bacterial host cells that metabolize and convert glycerol or volatile fatty acids (VFAs) to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV. The disclosure further provides methods of producing PHBV using the recombinant bacteria disclosed herein.

The invention provides microorganisms and methods for the production of polyhydroxybutyrate (PHB) from gaseous substrates. In particular, the invention provides a non-naturally occurring Wood-Ljungdahl microorganism comprising (a) an enzyme that converts acetyl-CoA to acetoacetyl-CoA, (b) an enzyme that converts acetoacetyl-CoA to 3-hydroxybutyryl-CoA, and (c) an enzyme that converts 3-hydroxybutyryl-CoA to polyhydroxybutyrate, and methods related thereto.