Abstract: According to the present invention, a process for producing a practical cholesterol-reduced substance by converting cholesterol contained in foods and feeds to coprostanol having very low intestinal tract absorbability by utilizing enzymatic action is provided. Cholesterol in a cholesterol-containing substance such as meat, egg, milk, seafood and cooked processed foods containing the same, or feeds for animals, poultry and pisciculture, and the like, can be treated with three kinds of enzymes which are a cholesterol dehydrogenase having an optimum pH in a neutral pH range and 4-cholesten-3-one dehydrogenase and coprostan-3-one dehydrogenase each having an optimum pH in a weak acidic range, or microbial cells containing the enzymes, for converting the cholesterol to coprostanol to reduce the amount of the cholesterol.

Abstract: The present invention provides a method for industrially advantageously producing (S)-4-hydroxy-2-ketoglutaric acid and for producing compounds which are formed by biosynthesis from the precursor (S)-4-hydroxy-2-ketoglutaric acid, for example, for producing the compounds (2S,4S)-4-hydroxy-L-glutamic acid and (2S,4S)-4-hydroxy-L-proline, using a recombinant microorganism carrying a recombinant DNA harboring the DNA fragment encoding 4(S)-4-hydroxy-2-ketoglutaric acid aldolase gene.

Abstract: The present invention provides a method for industrially advantageously producing (S)-4-hydroxy-2-ketoglutaric acid and for producing compounds which are formed by biosynthesis from the precursor (S)-4-hydroxy-2-ketoglutaric acid, for example, for producing the compounds (2S,4S)-4-hydroxy-L-glutamic acid and (2S,4S)-4-hydroxy-L-proline, using a recombinant microorganism carrying a recombinant DNA harboring the DNA fragment encoding 4(S)-4-hydroxy-2-ketoglutaric acid aldolase gene.

Abstract: An enzymatic process is presented for reducing the cholesterol level of foods and feeds by converting the cholesterol therein to coprostanol which has a very low intestinal tract absorbability. Cholesterol in meat, egg, milk, seafood and cooked processed foods containing the same, or feeds for animals, poultry, and pisiculture can be reduced by the sequential action of three enzymes isolated from a eubacterium: cholesterol dehydrogenase, 4-cholesten-3-one dehydrogenase and coprostan-3-one dehydrogenase.

Abstract: According to the present invention, a process for producing a practical cholesterol-reduced substance by converting cholesterol contained in foods and feeds to coprostanol having very low intestinal tract absorbability by utilizing enzymatic action is provided. Cholesterol in a cholesterol-containing substance such as meat, egg, milk, seafood and cooked processed foods containing the same, or feeds for animals, poultry and pisciculture, and the like, can be treated with three kinds of enzymes which are a cholesterol dehydrogenase having an optimum pH in a neutral pH range and 4-cholesten-3-one dehydrogenase and coprostan-3-one dehydrogenase each having an optimum pH in a weak acidic range, or microbial cells containing the enzymes, for converting the cholesterol to coprostanol to reduce the amount of the cholesterol.

Abstract: According to the present invention, a process for producing a practical cholesterol-reduced substance by converting cholesterol contained in foods and feeds to coprostanol having very low intestinal tract absorbability by utilizing enzymatic action is provided.

Abstract: The present invention provides a method for industrially advantageously producing (S)-4-hydroxy-2-ketoglutaric acid and for producing compounds which are formed by biosynthesis from the precursor (S)-4-hydroxy-2-ketoglutaric acid, for example, for producing the compounds (2S,4S)-4-hydroxy-L-glutamic acid and (2S,4S)-4-hydroxy-L-proline, using a recombinant microorganism carrying a recombinant DNA harboring the DNA fragment encoding 4(S)-4-hydroxy-2-ketoglutaric acid aldolase gene.

Abstract: The present invention provides a gene expression regulatory DNA and a process for preparing a protein using the same.A DNA derived from the isocitrate lyase (ICL) gene of a coryneform bacterium regulates expression of a structural gene encoding a protein when incorporated into a vector DNA together with said structural gene and introduced into a host coryneform bacterium, and a useful protein can be efficiently produced using the DNA.

Abstract: An object of the present invention is to provide a process for producing an optically active .gamma.-hydroxy-L-glutamic acid advantageously on an industrial scale. The present invention provides a process for producing an optically active .gamma.-hydroxy-L-glutamic acid, which comprises allowing biocatalyst I, an amino group donor, pyruvic acid and glyoxylic acid to coexist in an aqueous medium to form the optically active .gamma.-hydroxy-L-glutamic acid in the aqueous medium, and collecting the formed optically active .gamma.-hydroxy-L-glutamic acid therefrom, said biocatalyst I having activity of forming the optically active .gamma.-hydroxy-L-glutamic acid from pyruvic acid and glyoxylic acid in the presence of an amino group donor. The present invention also provides a process for producing an optically active .gamma.

Abstract: The present invention provides a process for producing substances such as L-tryptophan and L-threonine, which comprises transforming a serine-requiring microorganism belonging to the genus Corynebacterium or Brevibacterium by incorporation of a recombinant plasmid containing a gene which complements the serine-requirement of the host and a gene which relates to the biosynthesis of a desired substance; culturing the obtained transformant in a culture medium; allowing the substance produced by the transformant to accumulate in the culture; and recovering the substance from the culture.

Abstract: The present invention provides a process for producing an optically active 4-hydroxy-2-ketoglutaric acid, by mixing glyoxylic acid, pyruvic acid and a microorganism to form the optically active 4-hydroxy-2-ketoglutaric acid in an aqueous medium.

Abstract: Disclosed is a process for producing an aromatic amino acid selected from the group consisting of L-tryptophan, L-tyrosine and L-phenylalanine which comprises culturing in a medium a mutant strain of the genus Corynebacterium or Brevibacterium, being capable of producing the aromatic amino acid and also having higher transketolase activity than that of a parent strain thereof until the aromatic amino acid is produced and accumulated in the culture, and recovering the aromatic amino acid therefrom.

Abstract: The invention relates to a bacterial process for producing L-tryptophan, L-tyrosine or L-phenylalanine. The process utilizes a coryneform glutamic acid-producing bacterium being capable of producing L-tryptophan, L-tyrosine or L-phenylalanine and also decreased or lacked in phosphoenolpyruvate carboxylase activity. The mutant strain is then cultured in order to accumulate the amino acid in a medium and the amino acid is recovered therefrom.

Abstract: The present invention provides a process for producing substances such as L-tryptophan and L-threonine, which comprises transforming a serine-requiring microorganism belonging to the genus Corynebacterium or Brevibacterium by incorporation of a recombinant plasmid containing a gene which complements the serine-requirement of the host and a gene which relates to the biosynthesis of a desired substance; culturing the obtained transformant in a culture medium; allowing the substance produced by the transformant to accumulate in the culture; and recovering the substance from the culture.

Abstract: L-tryptophan is produced by constructing a recombinant DNA composed of a vector DNA and DNA fragments bearing all of genetic information relating to the synthesis of DS, AS, PRT, PRAI, InGPS and TS, introducing the recombinant DNA in a microorganism belonging to the genus Corynebacterium or Brevibacterium, culturing the microorganism in a medium, and recovering L-tryptophan accumulated in the culture.

Abstract: A process for producing alanine which comprises culturing in a medium a microorganism belonging to the genus Escherichia, Corynebacterium or Brevibacterium which has an L-alanine dehydrogenase activity and is capable of producing alanine, allowing the microorganism to produce and accumulate alanine in the culture medium, and recovering alanine from the culture medium.

Abstract: There is provided a process for producing L-valine which comprises cultivating, in a medium, a microorganism which belongs to the genus Corynebacterium or Brevibacterium, which exhibits a) an ability to produce L-valine, b) resistance to L-valine in a medium containing acetic acid as a sole carbon source, and c) sensitivity to a pyruvic acid analog in a medium containing glucose as a sole carbon source, until L-valine is accumulated in the culture broth, and recovering L-valine therefrom.

Abstract: The invention relates to coryneform microorganisms capable of assimilating lactose which carry a recombinant DNA capable of conferring the ability to assimilate lactose on coryneform microorganisms; and to a process for producing L-amino acids which comprises culturing said coryneform microorganism capable of assimilating lactose in a culture medium containing lactose to form an amino acid, and recovering said amino acid accumulated in the culture broth. Further, the invention relates to a method for preparing recombinant plasmids containing a DNA fragment essential to the expression of a gene in coryneform microorganisms.

Abstract: The invention relates to a bacterial process for producing L-tryptophan, L-tyrosine or L-phenylalanine. The process utilizes a coryneform glutamic acid-producing bacterium being capable of producing L-tryptophan, L-tyrosine or L-phenylalanine and also decreased or lacked in phosphoenolpyruvate carboxylase activity. The mutant strain is then cultured in order to accumulate the amino acid in a medium and the amino acid is recovered therefrom.

Abstract: A process for producing L-alanine, which comprises culturing in a medium a microorganism belonging to the genus Arthrobacter which has L-alanine dehydrogenase activity, but little or no alanine racemase activity, and which is capable of producing L-alanine; allowing L-alanine to accumulate in the culture; and recovering L-alanine from the culture.