The present invention provides engineered polypeptides that are useful for the asymmetric synthesis of β-hydroxy-α-amino acids under industrial-relevant conditions. The engineered polypeptides disclosed in this invention were developed through directed evolution based on the ability of catalytic synthesis of (2S, 3R)-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid. The present disclosure also provides polynucleotides encoding engineered polypeptides, host cells capable of expressing engineered polypeptides, and methods of producing β-hydroxy-α-amino acids using engineered polypeptides. Compared to other processes of preparation, the use of the engineered polypeptides of the present invention for the preparation of β-hydroxy-α-amino acids results in high purity of the desired stereoisomers, mild reaction conditions, low pollution and low energy consumption. So, it has good industrial application prospects.

The present invention provides engineered polypeptides that are useful for the asymmetric synthesis of β-hydroxy-α-amino acids under industrial-relevant conditions. The present disclosure also provides polynucleotides encoding engineered polypeptides, host cells capable of expressing engineered polypeptides, and methods of producing β-hydroxy-α-amino acids using engineered polypeptides. Compared to other processes of preparation, the use of the engineered polypeptides of the present invention for the preparation of β-hydroxy-α-amino acids results in high purity of the desired stereoisomers, mild reaction conditions, low pollution and low energy consumption. So, it has good industrial application prospects.

The present invention provides engineered polypeptides that are useful for the asymmetric synthesis of β-hydroxy-α-amino acids under industrial-relevant conditions. The engineered polypeptides disclosed in this invention were developed through directed evolution based on the ability of catalytic synthesis of (2S, 3R)-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid. The present disclosure also provides polynucleotides encoding engineered polypeptides, host cells capable of expressing engineered polypeptides, and methods of producing β-hydroxy-α-amino acids using engineered polypeptides. Compared to other processes of preparation, the use of the engineered polypeptides of the present invention for the preparation of β-hydroxy-α-amino acids results in high purity of the desired stereoisomers, mild reaction conditions, low pollution and low energy consumption. So, it has good industrial application prospects.

The invention provides a genetically modified eukaryotic microorganism for anaerobic production of essential amino acids and optionally the co-production of one or more co-products. The microorganism is genetically modified to redirect carbon flow from PEP via oxaloacetate and asparatate semialdehyde, towards the synthesis of increased amounts of essential amino acids. The microorganism may be genetically modified to produce increased amounts of one or more co-product by enhancing carbon flow from PEP via pyruvate, acetyl CoA and malonyl CoA to produce alcohols and lipids, such as triglycerides, fatty esters, fatty alcohols, fatty aldehydes, fatty amides. The invention provides a method for anaerobic production of essential amino acids using the genetically modified eukaryotic microorganism and optionally co-production of said one or more co-products. The genetically modified eukaryotic microorganism may be used for the anaerobic production of essential amino acids and optionally the co-production of said one or more co-products.

Provided is a method of producing a cured tobacco material having an enhanced threonine content. The present invention provides a method of producing a cured tobacco material having an enhanced threonine content, wherein the cured tobacco material is produced from a modified tobacco plant which has been modified such that expression or activity of an endogenous threonine aldolase is reduced or from a part of the modified tobacco plant.

The present invention provides engineered polypeptides that are useful for the asymmetric synthesis of -hydroxy--amino acids under industrial-relevant conditions. The present disclosure also provides polynucleotides encoding engineered polypeptides, host cells capable of expressing engineered polypeptides, and methods of producing -hydroxy--amino acids using engineered polypeptides. Compared to other processes of preparation, the use of the engineered polypeptides of the present invention for the preparation of -hydroxy--amino acids results in high purity of the desired stereoisomers, mild reaction conditions, low pollution and low energy consumption. So, it has good industrial application prospects.

A method for preparing glycine by using threonine relates to a fermentation process in which threonine is decomposed into glycine and acetaldehyde by aldolase. Glycine and acetyl coenzyme A can be produced in a fermentation process, in which acetaldehyde is reduced into acetyl coenzyme A or an acetyl coenzyme A derivative by acetylating acetaldehyde dehydrogenase; or threonine is dehydrogenated by threonine dehydrogenase to obtain 2-amino-3-ketobutyric acid, which is then ligated by 2-amino-3-ketobutyrate CoAligase to obtain acetyl coenzyme A. Coenzyme A can be converted into an acetyl coenzyme A derivative under different fermentation conditions.

The present invention concerns a metabolically engineered microorganism for glycine bioproduction or a salt or an ester thereof, the genome of said microorganism comprises an attenuation of the expression of genes encoding enzymes having glycine cleavage system activity as defined by E.C. 1.4.1.27 together with an overexpressing of threonine dehydrogenase dependent pathway as defined by EC E.C. 1.1.1.103 and E.C. 2.3.1.29 and/or with a threonine aldolase dependent pathway as defined by E.C. 4.1.2.48 or EC 4.1.2.42 or any of its catalytically active variants, its use for the production of glycine or one of its salts or esters. The present invention also concerns a fermentation process using said metabolically engineered microorganism for the production of glycine or one of its salts or esters.