A method is described for producing an objective substance, for example, an aldehyde such as vanillin. The objective substance is produced from a carbon source or a precursor of the objective substance by using a microorganism having an ability to produce the objective substance, wherein the microorganism has been modified to have a specific carboxylic acid reductase (CAR) gene, such as a Gordonia CAR gene, Novosphingobium CAR gene, or Coccomyxa CAR gene.

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.

The invention provides a non-naturally occurring bacterium having decreased or eliminated activity of an enzyme that catalyzes the reaction defined by EC 1.2.7.5, such as aldehyde:ferredoxin oxidoreductase (AOR). Optionally, the bacterium also has decreased or eliminated activity of an enzyme that catalyzes the reaction defined by EC 1.2.1.10 and/or EC 1.1.1.1, such as aldehyde dehydrogenase, alcohol dehydrogenase, or bifunctional aldehyde/alcohol dehydrogenase. The invention further provides methods of producing products by culturing the bacterium in the presence of a gaseous substrate containing one or more of CO, CO.sub.2, and H.sub.2.

The invention provides a process for reducing bio-catalytic oxidation of a product in a post-production stream. More particularly the invention provides a process for reducing bio-catalytic oxidation of an alcohol in a product stream, the product stream comprising an alcohol product, dissolved carbon dioxide, and at least one enzyme capable of oxidizing the alcohol. The invention finds applicability in fermentation processes, wherein a C1-fixing microorganism utilizes a C1-containing substrate to produce a fermentation product.

Provided herein are methods, compositions, and non-naturally occurring microbial organism for preparing compounds such as1-butanol, butyric acid, succinic acid, 1,4-butanediol, 1-pentanol, pentanoic acid, glutaric acid, 1,5-pentanediol, 1-hexanol, hexanoic acid, adipic acid, 1,6-hexanediol, 6-hydroxy hexanoic acid, ?-Caprolactone, 6-amino-hexanoic acid, ?-Caprolactam, hexamethylenediamine, linear fatty acids and linear fatty alcohols that are between 7-25 carbons long, linear alkanes and linear ?-alkenes that are between 6-24 carbons long, sebacic acid and dodecanedioic acid comprising: a) converting a C.sub.N aldehyde and pyruvate to a C.sub.N+3 ?-hydroxyketone intermediate through an aldol addition; and b) converting the C.sub.N+3 ?-hydroxyketone intermediate to the compounds through enzymatic steps, or a combination of enzymatic and chemical steps.

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.

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.