Disclosed herein are methods and compositions of matter that enable the biological conversion of gaseous waste streams (CO.sub.2, stranded natural gas, flue gas, biogas, landfill gas, etc.) to a platform chemical, 3-hydroxybutyrate, which can in turn be upgraded to fuels and polymers (e.g. polypropylene and polymers). The technology thus presents both a mechanism to valorize gaseous waste streams and establish sustainable production routes to chemicals and plastics via the overexpression of PHB depolymerase while knocking out the AACS pathway in this specific strain of methanotrophic bacteria.

Described is a method for the production of isobutene from 3-methylcrotonyl-CoA comprising the steps of:

(a) enzymatically converting 3-methylcrotonyl-CoA into 3-methylbutyric acid; and
(b) further enzymatically converting the thus produced 3-methylbutyric acid into isobutene.

The conversion of 3-methylcrotonyl-CoA into 3-methylbutyric acid can be achieved by first enzymatically converting 3-methylcrotonyl-CoA into 3-methylbutyryl-CoA and further enzymatically converting the thus produced 3-methylbutyryl-CoA into 3-methylbutyric acid. Alternatively, the conversion of 3-methylcrotonyl-CoA into 3-methylbutyric acid can be achieved by first enzymatically converting 3-methylcrotonyl-CoA into 3-methylcrotonic acid and then further enzymatically converting the thus produced 3-methylcrotonic acid into 3-methylbutyric acid.

Described is a method for the conversion of 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyric acid comprising the steps of:

(a) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA; and
(b) further enzymatically converting the thus produced 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid
wherein the enzymatic conversion of 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid according to step (b) is achieved by first converting 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyryl phosphate and then subsequently converting the thus produced 3-hydroxy-3-methylbutyryl phosphate into 3-hydroxy-3-methylbutyric acid.

Described is a recombinant organism or microorganism which is capable of enzymatically converting acetyl-CoA into isobutene, (A) wherein in said organism or microorganism: (i) acetyl-CoA is enzymatically converted into acetoacetyl-CoA, (ii) acetoacetyl-CoA is enzymatically converted into 3-hydroxy-3-methylglutaryl-CoA, (iii) 3-hydroxy-3-methylglutaryl-CoA is enzymatically converted into 3-methylglutaconyl-CoA, (iv) 3-methylglutaconyl-CoA is enzymatically converted into 3-methylcrotonyl-CoA, and (v) wherein said 3-methylcrotonyl-CoA is converted into isobutene by: (a) enzymatically converting 3-methylcrotonyl-CoA into 3-methylcrotonic acid which is then further enzymatically converted into said isobutene; or (b) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA which is then further enzymatically converted into 3-hydroxy-3-methylbutyric acid which is then further enzymatically converted into 3-phosphonoxy-3-methylbutyric acid which is then further enzymatically converted into said isobutene; (B) wherein said recombinant organism or microorganism has an increased pool of coenzyme A (CoA) over the organism or microorganism from which it is derived due to: (i) an increased uptake of pantothenate; and/or (ii) an increased conversion of pantothenate into CoA. Moreover, described is the use of such a recombinant organism or microorganism for the production of isobutene. Further, described is a method for the production of isobutene by culturing such a recombinant organism or microorganism in a suitable culture medium under suitable conditions.

Provided herein are microorganisms and methods for fermentative production of ß-ketoadipate from gaseous substrates such as carbon dioxide (CO.sub.2), carbon monoxide (CO), and/or hydrogen (H.sub.2). Additionally, the processes provided herein are methods for producing polymers containing ß-ketoadipate, that can potentially enable a circular economy by diverting waste, e.g., plastic waste.

Described is a method for the enzymatic production of an acyl phosphate from a 2-hydroxyaldehyde using a phosphoketolase or a sulfoacetaldehyde acetyltransferase.

Described is a method for the enzymatic production of an acyl phosphate from a 2-hydroxyaldehyde using a phosphoketolase or a sulfoacetaldehyde acetyltransferase.

Described is a method for the conversion of 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyric acid comprising the steps of: (a) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA; and (b) further enzymatically converting the thus produced 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid wherein the enzymatic conversion of 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid according to step (b) is achieved by first converting 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyryl phosphate and then subsequently converting the thus produced 3-hydroxy-3-methylbutyryl phosphate into 3-hydroxy-3-methylbutyric acid.

The present invention provides microorganisms capable of converting acetyl-coA into crotyl alcohol as well as fermentation methods for producing crotyl alcohol, either alone, or in combination with acetone and/or isopropanol. The microorganisms may be genetically engineered to express and/or disrupt one or more of the following enzymes: acetaldehyde dehydrogenase, alcohol dehydrogenase, bifunctional acetaldehyde/alcohol dehydrogenase, aldehyde oxidoreductase, phosphotransacetylase, acetate kinase, CoA-transferase A, CoA-transferase B, acetoacetate decarboxylase, secondary alcohol dehydrogenase, butyryl-CoA dehydro genase (BCD), and/or trans-2-enoyl-CoA reductase (TER).

The invention relates to a genetically engineered bacterium having an enzyme that converts 3-hydroxyisovaleryl-CoA to 3-hydroxyisovalerate and an enzyme that converts 3-hydroxyisovalerate to isobutylene. Typically, the bacterium is capable of producing isobutylene from a gaseous substrate containing CO, CO.sub.2, and/or H.sub.2, such as syngas or an industrial waste gas.