The disclosure provides genetically engineered microorganisms and methods for improved biological production of ethylene glycol and precursors of ethylene glycol. The microorganism of the disclosure produces ethylene glycol or a precursor of ethylene glycol through one or more of 5,10-methylenetetrahydrofolate, oxaloacetate, citrate, malate, and glycine. The disclosure further provides compositions comprising ethylene glycol or polymers of ethylene glycol such as polyethylene terephthalate.

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 disclosure relates to a Corynebacterium glutamicum mutant strain having enhanced L-lysine productivity and a method of producing L-lysine using the same. The Corynebacterium glutamicum mutant strain may produce L-lysine in an improved yield by inhibiting the conversion of oxaloacetate to citrate due to decreased or inhibited expression of the gene encoding the citrate synthase.

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 disclosure provides processes for producing alkylated fatty acids and derivatives thereof. In at least one embodiment, a process includes introducing a terminal alkyl transferase and a fatty acid into a bioreactor. The process includes introducing an internal methyl transferase and internal methyl reductase into the bioreactor or a second bioreactor. The process includes obtaining an alkylated fatty acid having a methyl substituent located at an internal carbon atom of the fatty acid and a methyl substituent or ethyl substituent located at a carbon atom alpha to the terminal carbon atom of the fatty acid.

The present disclosure provides processes for producing alkylated fatty acids and derivatives thereof. In at least one embodiment, a process includes introducing a terminal alkyl transferase and a fatty acid into a bioreactor. The process includes introducing an internal methyl transferase and internal methyl reductase into the bioreactor or a second bioreactor. The process includes obtaining an alkylated fatty acid having a methyl substituent located at an internal carbon atom of the fatty acid and a methyl substituent or ethyl substituent located at a carbon atom alpha to the terminal carbon atom of the fatty acid.

The disclosure provides genetically engineered microorganisms and methods for improved biological production of ethylene glycol and precursors of ethylene glycol. The microorganism of the disclosure produces ethylene glycol or a precursor of ethylene glycol through one or more of 5,10-methylenetetrahydrofolate, oxaloacetate, citrate, malate, and glycine. The disclosure further provides compositions comprising ethylene glycol or polymers of ethylene glycol such as polyethylene terephthalate.

The present disclosure relates to a citrate synthase variant, a microorganism comprising the variant, and a method for producing L-amino acids using the microorganism.

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%.

Provided are a theanine-producing strain and use thereof in tea fermentation production. A corynebacterium glutamicum is proposed, which includes an alanine decarboxylase CsAlaDC mutant. The theanine-producing strain is obtained by taking the corynebacterium glutamicum as a starting strain, knocking out in sequence an -ketoglutarate dehydrogenase E1 subunit gene odhA, a glutamate external transporter gene Ncg11221 and a lactate dehydrogenase gene ldh; and/or expressesing a citrate synthase gene gltA, a pyruvate kinase gene pyk and a glutamate dehydrogenase gene gdh; and/or overexpressing an alanine dehydrogenase alaA and integrating a -glutamine synthetase GMAS into a cg1960 pseudogene locus of the corynebacterium glutamicum.