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-methyl butyryl-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.

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.

The invention relates to a genetically engineered bacterium having an enzyme that converts acetyl-CoA to acetoacetyl-CoA, an enzyme that converts acetoacetyl-CoA to 3-hydroxybutyryl-CoA, and an enzyme that converts 3-hydroxybutyryl-CoA to 3-hydroxybutyrate. The bacterium may also have enzymes to produce other downstream products, such as 3-hydroxybutyryaldehyde, and 1,3-butanediol. Typically, the bacterium is capable of producing these products from a gaseous substrate, such as syngas or an industrial waste gas.

The invention relates to a genetically engineered bacterium having an enzyme that converts acetyl-CoA to acetoacetyl-CoA, an enzyme that converts acetoacetyl-CoA to 3-hydroxybutyryl-CoA, and an enzyme that converts 3-hydroxybutyryl-CoA to 3-hydroxybutyrate. The bacterium may also have enzymes to produce other downstream products, such as 3-hydroxybutyryaldehyde, and 1,3-butanediol. Typically, the bacterium is capable of producing these products from a gaseous substrate, such as syngas or an industrial waste gas.

Provided herein are microorganisms and methods for fermentative production of -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 -ketoadipate, that can potentially enable a circular economy by diverting waste, e.g., plastic waste.

The invention relates to a genetically engineered bacterium comprising an energy-generating fermentation pathway and methods related thereto. In particular, the invention provides a bacterium comprising a phosphate butyryltransferase (Ptb) and a butyrate kinase (Buk) (Ptb-Buk) that act on non-native substrates to produce a wide variety of products and intermediates. In certain embodiments, the invention relates to the introduction of Ptb-Buk into a C1-fixing microoorgansim capable of producing products from a gaseous substrate.

The invention relates to a genetically engineered bacterium comprising an energy-generating fermentation pathway and methods related thereto. In particular, the invention provides a bacterium comprising a phosphate butyryltransferase (Ptb) and a butyrate kinase (Buk) (Ptb-Buk) that act on non-native substrates to produce a wide variety of products and intermediates. In certain embodiments, the invention relates to the introduction of Ptb-Buk into a C1-fixing microoorgansim capable of producing products from a gaseous substrate.

The present invention relates to 25 hitherto undescribed genes of B. licheniformis and gene products derived thereform and all sufficiently homologous nucleic acids and proteins thereof. They occur in five different metabolic pathways for the formation of odorous substances. The metabolic pathways in question are for the synthesis of: 1) isovalerian acid (as part of the catabolism of leucine), 2) 2-methylbutyric acid and/or isobutyric acid (as part of the catabolism of valine and/or isoleucine), 3) butanol and/or butyric acid (as part of the metabolism of butyric acid), 4) propyl acid (as part of the metabolism of propionate) and/or 5) cadaverine and/or putrescine (as parts of the catabolism of lysine and/or arginine). The identification of these genes allows biotechnological production methods to be developed that are improved to the extent that, to assist these nucleic acids, the formation of the odorous substances synthesised via these metabolic pathways can be reduced by deactivating the corresponding genes in the micro-organism used for the biotechnological production. In addition, these gene products are thus available for preparing reactions or for methods according to their respective biochemical properties.

A genetically engineered strain of Escherichia coli Nissle 1917 (EcN) with a modified genome designed to enhance the production of short-chain fatty acids (SCFAs) is provided. The engineered genome includes the atoB gene from E. coli K-12, responsible for encoding acetyl-CoA acetyltransferase, a crt-bcd-etfA-etfB-BHBD gene cluster from E. C. butyricum that encodes enzymes involved in the synthesis of SCFAs, specifically enoyl-CoA hydratase, butyryl-CoA dehydrogenase, and electron transfer flavoproteins, and the ptb-buk gene from C. acetobutyricum, which encodes phosphotransbutyrylase and butyrate kinase. Additionally, key genes associated with competing metabolic pathwaysldhA, frdABCD, adhE, ackA, and ptaare deleted to optimize SCFA production, particularly butyrate. This strain is intended for use in therapeutic applications where enhanced SCFA production is beneficial, such as in the treatment of coronary heart disease.

The present invention relates to a recombinant organism or microorganism having a decreased pool of crotonic acid compared to the organism or microorganism from which it is derived due to at least one of: (i) an increased conversion of crotonyl-CoA into butyryl-CoA; and/or an increased conversion of butyryl-CoA into butyric acid; (ii) an increased conversion of crotonyl-CoA into 3-hydroxybutyryl-CoA; and/or an increased conversion of 3-hydroxybutyryl-CoA into 3-hydroxybutyric acid; (iii) an increased conversion of crotonic acid into crotonyl-CoA; (iv) an increased conversion of crotonyl-[acyl-carrier protein] into butyryl [acyl-carrier-protein]; (v) a decreased conversion of crotonyl-CoA into crotonic acid; and/or (vi) a decreased conversion of crotonyl-[acyl-carrier protein] into crotonic acid. Moreover, the present invention relates to the use of such a recombinant organism or microorganism for the production of alkenes with the enzyme ferulic acid decarboxylase. Further, the present invention relates to a method for the production of isobutene or butadiene by culturing such a recombinant organism or microorganism in a suitable culture medium under suitable conditions.