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

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

The present disclosure relates to modified homoserine dehydrogenase and a method for producing a homoserine-derived L-amino acid using the same.

The present disclosure relates to modified homoserine dehydrogenase and a method for producing a homoserine-derived L-amino acid using the same.

The present invention generally relates to the microbiological industry, and specifically to the production of L-serine or L-serine derivatives using genetically modified bacteria. The present invention provides genetically modified microorganisms, such as bacteria, wherein the expression of genes encoding for enzymes involved in the degradation of L-serine is attenuated, such as by inactivation, which makes them particularly suitable for the production of L-serine at higher yield. The present invention also provides means by which the microorganism, and more particularly a bacterium, can be made tolerant towards higher concentrations of serine. The present invention also provides methods for the production of L-serine or L-serine derivative using such genetically modified microorganisms.

The present invention generally relates to the microbiological industry, and specifically to the production of L-serine or L-serine derivatives using genetically modified bacteria. The present invention provides genetically modified microorganisms, such as bacteria, wherein the expression of genes encoding for enzymes involved in the degradation of L-serine is attenuated, such as by inactivation, which makes them particularly suitable for the production of L-serine at higher yield. The present invention also provides means by which the microorganism, and more particularly a bacterium, can be made tolerant towards higher concentrations of serine. The present invention also provides methods for the production of L-serine or L-serine derivative using such genetically modified microorganisms.

A transformant obtained by introducing a DNA of (a1), (a2), or (a3) below, and (b) an alcohol dehydrogenase gene, into a bacterium of the genus Hydrogenophilus, can efficiently produce isobutanol utilizing carbon dioxide as a sole carbon source. (a1) DNA which consists of a base sequence of SEQ ID NO: 1; (a2) DNA which consists of a base sequence having 90% or more identity with SEQ ID NO: 1, the DNA encoding a polypeptide having 2-keto-acid decarboxylase activity; (a3) DNA which hybridizes with a DNA consisting of a base sequence complementary to SEQ ID NO: 1 under stringent conditions, and which encodes a polypeptide having 2-keto-acid decarboxylase activity.

Provided is a method of producing a product by culturing a carboxydotrophic acetogenic bacterium with a disrupting mutation in a lactate dehydrogenase enzyme in the presence of a substrate comprising CO, CO.sub.2, and/or H.sub.2. Preferably, the disrupting mutation reduces or eliminates the expression or activity of the enzyme such that the bacterium produces a reduced amount of lactate or no lactate.

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.