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.

A recombinant yeast cell, fermentation compositions, and methods of use thereof are provided. The recombinant yeast cell includes at least one heterologous nucleic acid encoding one or more polypeptide having phosphoketolase activity; phosphotransacetylase activity; and/or acetylating acetaldehyde dehydrogenase activity, wherein the cell does not include a heterologous modified xylose reductase gene, and wherein the cell is capable of increased biochemical end product production in a fermentation process when compared to a parent yeast cell.

The invention relates to a method for homo-ethanol production from lactose using a genetically modified lactic acid bacterium of the invention, where the cells are provided with a substrate comprising dairy waste supplemented with an amino nitrogen source (such as acid hydrolysed corn steep liquor). The invention further relates to genetically modified lactic acid bacterium and its use for homo-ethanol production from lactose in dairy waste. The lactic acid bacterium comprises both genes (lacABCD, LacEF, lacG) encoding enzymes catalysing the lactose catabolism pathway; and transgenes (pdc and adhB) encoding enzymes catalysing the conversion of pyruvate to ethanol. Additionally a number of genes (ldh, pta and adhE) are deleted in order to maximise homo-ethanol production as compared to production of lactate, acetoin and acetate production.

The present invention provides an engineered cyanobacterium, comprising at least one plasmid selected from three novel pathways to produce acetate, which can convert atmospheric carbon dioxide as a raw material into acetate. The present invention also constructs the expression plasmid for three different transporters specific to acetate to be expressed in cyanobacteria, which comprises putative ABC transporter (AatA), succinate/acetate: proton symporter (SatP) and acetate/glycolate: cation symporter (ActP). Therefore, the engineered cyanobacteria of the present invention can produce 0.58 mg/L to 3.54 mg/L of acetate per hour.

The present invention relates to a microorganism having improved L-lysine-producing ability and an L-lysine-producing method using the same. More specifically, the present invention relates to a microorganism of the genus of Corynebacterium, in which acetate kinase activity is further enhanced over inherent activity, and an L-lysine-producing method using the same.

The present invention belongs to the bioengineering field, and relates to a method for fermentation production of L-theanine by using an Escherichia coli genetically engineered bacterium. The engineered bacterium is obtained by serving a strain as an original strain, wherein the strain is obtained after performing a single copy of T7RNAP, a dual copy of gmas, xylR knockout, and sucCD knockout on an Escherichia coli W3110 genome, and by integrating genes xfp, pta, acs, gltA, and ppc, and knocking out ackA on the genome. The present invention has a high yield, and stable production performance; after 20-25 h, L-theanine has a titer of 75-80 g/L, and the yield is up to 52-55%. The fermentation broth is purified by membrane separation in combination with a cation-anion resin series technique. Moreover, the one-step crystallization yield is 72.3% and the L-theanine final product has a purity of 99%.

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.

The invention provides for methods for the production of mevalonate, isoprene, isoprenoid precursor molecules, and/or isoprenoids in cells via the heterologous expression of phosphoketolase enzymes.

Mutant thermophilic organisms that consume a variety of biomass derived substrates are disclosed herein. Strains of Thermoanaerobacterium saccharolyticum with acetate kinase and phosphotransacetylase expression eliminated are disclosed herein. Further, strain ALK1 has been engineered by site directed homologous recombination to knockout both acetic acid and lactic acid production. Continuous culture involving a substrate concentration challenge lead to evolution of ALK1, and formation of a more robust strain designated ALK2. The organisms may be utilized for example in thermophilic SSF and SSCF reactions performed at temperatures that are optimal for cellulase activity to produce near theoretical ethanol yields without expressing pyruvate decarboxylase.

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.