Abstract: L-cysteine is produced by culturing an Escherichia bacterium having L-cysteine producing ability and containing a gene encoding an O-acetylserine sulphydrylase B or MalY regulatory protein that is modified so that cysteine desulfhydrase activity is reduced or eliminated. The bacterium is cultured in a medium to produce and cause accumulation of L-cysteine in the medium, and collecting L-cysteine from the medium.

Abstract: L-cysteine is produced by culturing an Escherichia bacterium having L-cysteine producing ability and containing a gene encoding an O-acetylserine sulphydrylase B or MalY regulatory protein that is modified so that cysteine desulfhydrase activity is reduced or eliminated. The bacterium is cultured in a medium to produce and cause accumulation of L-cysteine in the medium, and collecting L-cysteine from the medium.

Abstract: L-Cysteine is produced by culturing a microorganism having an ability to produce L-cysteine and modified so that expression of emrAB, emrKY, yojIH, acrEF, bcr, or cusA gene should be enhanced in a medium to produce and accumulate L-cysteine in the medium and collecting the L-cysteine from the medium. Genes coding for novel L-cysteine-excreting proteins are identified, and utilized for breeding of L-cysteine-producing microorganism to provide a novel method of producing L-cysteine.

Abstract: L-cysteine is produced by culturing an Escherichia bacterium having L-cysteine producing ability and containing a gene encoding an O-acetylserine sulphydrylase B or MalY regulatory protein that is modified so that cysteine desulfhydrase activity is reduced or eliminated. The bacterium is cultured in a medium to produce and cause accumulation of L-cysteine in the medium, and collecting L-cysteine from the medium.

Abstract: A peptide according to the present invention is selected from the group consisting of: (a) a peptide having the amino acid sequence represented by SEQ ID NO: 1; (b) a peptide having a modified amino acid sequence of the amino acid sequence described in (a) above, in which one or more amino acid residues are deleted, substituted, inserted or added, and having cell death-preventing activity and/or cell growth-promoting activity; and (c) a peptide which has an amino acid sequence having at least 80% homology with the peptide consisting of the amino acid sequence described in (a) above and has cell death-preventing activity and/or cell growth-promoting activity. The peptide has cell death-preventing activity and/or cell growth-promoting activity, is highly safe, and can be produced without difficulty. The peptide is useful as a culture supplement or as an effective component for a cell culture medium.

Abstract: An objective of the present invention is to provide a new protein derived from the silkworm middle silk gland and a DNA encoding said protein. The present invention relates to a protein of the following (a) or (b): (a) a protein comprising the amino acid sequence represented by SEQ ID NO: 1; (b) a protein comprising a modified amino acid sequence of the amino acid sequence described in (a) above, in which one or more amino acid residues are deleted, substituted, inserted or added, and having protease activity.

Abstract: L-cysteine is produced by culturing a coryneform bacterium in which intracellular serine acetyltransferase activity is increased by transformation with a gene coding for serine acetyltransferase, such modification of an expression control sequence of a gene coding for serine acetyltransferase that expression of the gene in a cell should be enhanced and for forth, preferably in which L-cysteine decomposition system is further suppressed, in a medium to produce and accumulate L-cysteine in culture and collecting the L-cysteine from the culture.

Abstract: L-Cysteine is produced by culturing a microorganism having an ability to produce L-cysteine and modified so that expression of emrAB, emrKY, yojIH, acrEF, bcr, or cusA gene should be enhanced in a medium to produce and accumulate L-cysteine in the medium and collecting the L-cysteine from the medium. Genes coding for novel L-cysteine-excreting proteins are identified, and utilized for breeding of L-cysteine-producing microorganism to provide a novel method of producing L-cysteine.

Abstract: L-Cysteine is produced by culturing a bacterium belonging to the genus Escherichia having an L-cysteine producing ability and modified so that cystathionine-?-lyase activity or cystathionine-?-lyase activity and tryptophanase activity should be reduced or eliminated in a medium to produce and accumulate L-cysteine in the medium and collecting the L-cysteine from the medium.

Abstract: A peptide according to the present invention is selected from the group consisting of: (a) a peptide having the amino acid sequence represented by SEQ ID NO: 1; (b) a peptide having a modified amino acid sequence of the amino acid sequence described in (a) above, in which one or more amino acid residues are deleted, substituted, inserted or added, and having cell death-preventing activity and/or cell growth-promoting activity; and (c) a peptide which has an amino acid sequence having at least 80% homology with the peptide consisting of the amino acid sequence described in (a) above and has cell death-preventing activity and/or cell growth-promoting activity. The peptide has cell death-preventing activity and/or cell growth-promoting activity, is highly safe, and can be produced without difficulty. The peptide is useful as a culture supplement or as an effective component for a cell culture medium.

Abstract: An objective of the present invention is to provide a means to prevent freeze-induced decrease in protein activity. The present invention relates to a method for preventing freeze-induced decrease in protein activity comprising adding a polypeptide comprising the following amino acid sequence (I) to a protein to be frozen. Further, the present invention relates to use of a polypeptide comprising the following amino acid sequence (I) to produce an agent for preventing freeze-induced decrease in protein activity: (SEQ ID NO: 1) Ser-Ser-Thr-Gly-Ser-X1-Ser-X2-Thr-Asp-X3-X4-X5-X6- X7-X8-Gly-Ser-X9-Thr-Ser-Gly-Gly-Ser-Ser-Thr-Tyr- Gly-Tyr-Ser-Ser-X10-X11-X12-X13-Gly-X14-Val (I).

Abstract: An objective of the present invention is to provide a new protein derived from the silkworm middle silk gland and a DNA encoding said protein. The present invention relates to a protein of the following (a) or (b): (a) a protein comprising the amino acid sequence represented by SEQ ID NO: 1; (b) a protein comprising a modified amino acid sequence of the amino acid sequence described in (a) above, in which one or more amino acid residues are deleted, substituted, inserted or added, and having protease activity.

Abstract: L-Cysteine is produced by culturing a bacterium belonging to the genus Escherichia having an L-cysteine producing ability and modified so that cystathionine-&bgr;-lyase activity or cystathionine-&bgr;-lyase activity and tryptophanase activity should be reduced or eliminated in a medium to produce and accumulate L-cysteine in the medium and collecting the L-cysteine from the medium.

Abstract: An objective of the present invention is to provide a means to prevent freeze-induced decrease in protein activity. The present invention relates to a method for preventing freeze-induced decrease in protein activity comprising adding a polypeptide comprising the following amino acid sequence (I) to a protein to be frozen. Further, the present invention relates to use of a polypeptide comprising the following amino acid sequence (I) to produce an agent for preventing freeze-induced decrease in protein activity: 1 (SEQ ID NO: 1) Ser-Ser-Thr-Gly-Ser-X1-Ser-X2-Thr-Asp-X3-X4-X5-X6- X7-X8-Gly-Ser-X9-Thr-Ser-Gly-Gly-Ser-Ser-Thr-Tyr- Gly-Tyr-Ser-Ser-X10-X11-X12-X13-Gly-X14-Val (I).

Abstract: L-cysteine is produced by culturing a coryneform bacterium in which intracellular serine acetyltransferase activity is increased by transformation with a gene coding for serine acetyltransferase, such modification of an expression control sequence of a gene coding for serine acetyltransferase that expression of the gene in a cell should be enhanced and for forth, preferably in which L-cysteine decomposition system is further suppressed, in a medium to produce and accumulate L-cysteine in culture and collecting the L-cysteine from the culture.

Abstract: A levodione reductase having the following physical properties is provided: molecular weight: from about 142,000 to about 155,000±10,000 (consisting of four homologous subunits having a molecular weight of 36,000±5,000); co-factor: nicotinamide adenine dinucleotide (AND/NADH); substrate specificity: active on levodione; optimum temperature: about 15° C. to about 20° C. at pH 7.0; optimum pH: 7.5; and activator: K+, Cs+, Rb+, Na+ and NH4+. The levodione reductase according to the present invention produces actinol, an important intermediate for the production of zeaxanthin, from levodione. This enzyme may be produced from a microorganism belonging to the genus Corynebacterium, preferably the microorganism Corynebacterium aquaticum AKU 611 (FERM BP-6448) or a functional equivalent, subculture, mutant or variant thereof.

Abstract: A process for producing L-lysine, which comprises culturing a mutant L-lysine-producing strain belonging to the genus Brevibacterium or the genus Corynebacterium and having selenalysine resistance in a nutrient medium, producing and accumulating L-lysine in the culture broth and collecting L-lysine from the culture broth.

Abstract: A basic L-amino acid and an acidic L-amino acid may be concurrently produced by either culturing a basic L-amino acid-producing bacteria under conditions for producing an acidic L-amino acid or mix-culturing a basic L-amino acid-producing bacteria and an acidic L-amino acid-producing bacteria.

Abstract: L-lysine is produced by culturing, in a medium, an L-lysine-producing mutant which belongs to the genus Corynebacterium thermoaminogenes which is capable of growing at 40.degree. C. or higher and which has resistance to S-(2-aminoethyl)-L-cysteine thereby producing and accumulating L-lysine in the culture medium, and collecting L-lysine from the culture medium.

Abstract: A basic L-amino acid and an acidic L-amino acid may be concurrently produced by either culturing a basic L-amino acid-producing bacteria under conditions for producing an acidic L-amino acid or mix-culturing a basic L-amino acid-producing bacteria and an acidic L-amino acid-producing bacteria.