?The invention is directed to a non-naturally occurring microbial organism comprising a first attenuation of a succinyl-CoA synthetase or transferase and at least a second attenuation of a succinyl-CoA converting enzyme or a gene encoding a succinate producing enzyme within a multi-step pathway having a net conversion of succinyl-CoA to succinate.

Disclosed is a microorganism of Escherichia sp. producing O-acetyl homoserine, and a method of producing O-acetyl homoserine in high yield using the microorganism.

The present application discloses genetically modified yeast cells comprising an active 3-HP fermentation pathway, and the use of these cells to produce 3-HP.

Methods of redirecting carbon flux and increasing C2/C3 or a C4/5/6 carbon chain length carbon-based chemical product yield in an organism, nonnaturally occurring organisms with redirected carbon flux and increased C2/C3 or C4/5/6 carbon chain length carbon-based chemical product yield and methods for using these organisms in production of C2/C3 or C4/5/6 carbon chain length carbon-based chemical products are provided.

The invention features compositions and methods for the increased production of mevalonate, isoprene, isoprenoid precursor molecules, and/or isoprenoids in microorganisms by engineering a microorganism for increased carbon flux towards mevalonate production in the following enzymatic pathways: (a) citrate synthase, (b) phosphotransacetylase, (c) acetate kinase, (d) lactate dehydrogenase, (e) malic enzyme, and (f) pyruvate dehydrogenase such that one of more of the enzyme activity is modulated. In addition, production of mevalonate, isoprene, isoprenoid precursor molecules, and/or isoprenoids can be further enhanced by the heterologous expression of the mvaE and mvaS genes (such as, but not limited to, mvaE and mvaS genes from the organisms Listeria grayi DSM 20601, Enterococcus faecium, Enterococcus gallinarum EG2, and Enterococcus casseliflavus).

The present application discloses genetically modified yeast cells comprising an active 3-HP fermentation pathway, and the use of these cells to produce 3-HP.

The present disclosure provides methods for increasing drought resistance and heat resistance of a plant. The methods encompass expression of at least one heat shock protein (HSP) from the group consisting of HSP40, HSP60 or HSP70 together with a phosphoenolpyruvate carboxylase (PEPC) comprising an aspartic acid (D) at a position that corresponds to the position 509 of SEQ ID NO: 4, in the plant. In comparison to a plant not manipulated in this manner, the disclosed, genetically-modified, plants display improved drought resistance and heat resistance. Also provided are plants that can be obtained by the method according to the invention, and nucleic acid vectors to be used in the described methods.

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 present application discloses genetically modified yeast cells comprising an active 3-HP fermentation pathway, and the use of these cells to produce 3-HP.

A system for carbon fixation is provided. The system comprises enzymes which catalyze reactions of a carbon fixation pathway, wherein at least one of the reactions of the carbon fixation pathway is a carboxylation reaction, wherein products of the reactions of the carbon fixation pathway comprise oxaloacetate and malonyl-CoA, wherein an enzyme which performs the carboxylation reaction is selected from the group consisting of phophoenolpyruvate (PEP) carboxlase, pyruvate carboxylase and acetyl-CoA carboxylase and wherein an export product of the carbon fixation pathway is glyoxylate. Additional carbon fixation pathways are also provided and methods of generating same.