The present disclosure relates to an additive used in a methionine preparation process, and a methionine preparation method. The additive provided by the present disclosure is a mixture containing components A, B, and C; component A has a structure represented by the following general formula (1); component B has a structure represented by the following general formula (2); component C is silicone oil; RCON(CH.sub.3)CH.sub.2CH.sub.2SO.sub.3Na (1). The methionine preparation method provided in the present invention comprises subjecting methionine to crystallization and/or recrystallization in the presence of the additive provided by the present disclosure. The additive provided by the present disclosure results in uniform emulsification, has good stability, can be used stably for a long time, and is suitable for a continuous crystallization process. The prepared methionine crystal has a good crystal form, a large bulk density, and good flowability. In addition, according to the methionine preparation method of the present disclosure, a crystallization system can operate continuously and stably for a long time without obvious foaming, and the crystallization process of the methionine product can proceed smoothly.

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An L-methionine-producing microorganism into which a metZ gene is introduced and a method of producing L-methionine using the same.

An L-methionine-producing microorganism into which a metZ gene is introduced and a method of producing L-methionine using the same.

The present disclosure provides novel bacterial strains with altered expression or start codon modification of one or more RNA degradation/processing genes. The RNA degradation genes of the present disclosure are controlled by heterologous promoters. The present disclosure further describes methods for generating microbial strains comprising heterologous promoter sequences operably linked to RNA degradation/processing genes.

The present disclosure provides novel bacterial strains with altered expression or start codon modification of one or more RNA degradation/processing genes. The RNA degradation genes of the present disclosure are controlled by heterologous promoters. The present disclosure further describes methods for generating microbial strains comprising heterologous promoter sequences operably linked to RNA degradation/processing genes.

The present disclosure relates to a modified polypeptide with attenuated activity of citrate synthase and a method for producing an aspartate-derived L-amino acid using the modified polypeptide.

The present disclosure relates to a modified polypeptide with attenuated activity of citrate synthase and a method for producing an aspartate-derived L-amino acid using the modified polypeptide.

The present disclosure relates to a modified polypeptide with attenuated activity of citrate synthase and a method for producing an aspartate-derived L-amino acid using the modified polypeptide.

The present disclosure relates to a modified polypeptide with attenuated activity of citrate synthase and a method for producing an aspartate-derived L-amino acid using the modified polypeptide.

Metabolites produced by a microorganism using oxaloacetate, pyruvate and/or acetyl-CoA as substrate or co-substrate upstream in the biosynthesis pathway, and more particularly using oxaloacetate. There is indeed a need in the art for transformed, in particular recombinant, microorganisms having at least an increased ability to produce oxaloacetate, pyruvate and/or acetyl-CoA, and in particular oxaloacetate, thus allowing an increased capacity to produce metabolites produced using oxaloacetate, pyruvate and/or acetyl-CoA as substrate or co-substrate upstream in the biosynthesis pathway, and in particular amino acids and their derivatives thereof, fatty acids, derivatives from the mevalonate pathway (in particular farnesyl, squalene, lanosterol, cholesterol and derivatives, and dolichols), flavonoides and/or polyketides. The solution proposed is the use of a genetically modified yeast comprising many modifications as described in the present text.