The present disclosure provides a method for detecting L-serine based on cysteine desulfurase-containing living Escherichia coli cells, and belongs to the technical field of amino acid detection. The method includes the following steps: incubating an unknown sample with the cysteine desulfurase-containing living E. coli cells to produce a red substance, and qualitatively or semi-quantitatively detecting L-serine content in the unknown sample according to color changes of the red substance of the living E. coli cells, or quantitatively detecting L-serine content in the unknown sample by measuring absorbance of a lysate of the living E. coli cells. The detection method provided by the present disclosure is simple and convenient in process, few in reaction steps and stable in enzymatic activity of living cells.

The present disclosure provides a method for detecting L-serine based on Escherichia coli cysteine desulfurase, and belongs to the technical field of amino acid detection. The method includes the steps of: reacting an unknown sample containing L-serine with E. coli cysteine desulfurase in vitro to produce a red substance, and qualitatively or quantitatively determining L-serine content in the unknown sample by observing a color of the red substance or determining content thereof. The method provided by the present disclosure is simple and feasible in technical operation, few in reaction steps, and capable of directly qualitatively detecting by naked eyes and quantitatively detecting the L-serine content.

The present invention relates to a novel thermophile-derived keratinase having keratin decomposition ability. Further, the present invention relates to a polynucleotide encoding the keratinase, a recombinant vector containing the same, host cells transformed by using the recombinant vector, and a method for preparing a keratinase including a step of culturing the host cells. Further, the present invention relates to a composition for decomposing keratin containing the enzyme; and a method for decomposing keratin by using the same. Further, the present invention relates to a keratin decomposed product decomposed by the enzyme.

The keratinase according to the present invention rapidly and effectively decomposes hardly-decomposable keratin, and thus it is expected that the keratinase can be used for the effective treatment and the high value-added resource recovery of agricultural and livestock waste, which causes environmental problems (for example, a novel material for enzyme cosmetics), and can be used in an innovative enzymatic bioconversion technique utilizing various decomposition enzyme groups.

The purpose of the present invention is to provide an organism having an ergothioneine productivity that is capable of easily producing ergothioneine within a short period of time at a high yield, as compared with a conventional technology, and, therefore, enables ergothioneine production on an industrial scale. This purpose can be achieved by a transformed fungus into which a gene encoding enzyme (1) or genes encoding enzymes (1) and (2) have been inserted and in which the inserted gene(s) are overexpressed. (1) an enzyme catalyzing a reaction of synthesizing hercynyl cysteine sulfoxide from histidine and cysteine in the presence of S-adenosyl methionine, iron (II) and oxygen. (2) An enzyme catalyzing a reaction of synthesizing ergothioneine from hercynyl cysteine sulfoxide using pyridoxal 5′-phosphate as a coenzyme.

The purpose of the present invention is to provide an organism having an ergothioneine productivity that is capable of easily producing ergothioneine within a short period of time at a high yield, as compared with a conventional technology, and, therefore, enables ergothioneine production on an industrial scale. This purpose can be achieved by a transformed fungus into which a gene encoding enzyme (1) or genes encoding enzymes (1) and (2) have been inserted and in which the inserted gene(s) are overexpressed. (1) an enzyme catalyzing a reaction of synthesizing hercynyl cysteine sulfoxide from histidine and cysteine in the presence of S-adenosyl methionine, iron (II) and oxygen. (2) An enzyme catalyzing a reaction of synthesizing ergothioneine from hercynyl cysteine sulfoxide using pyridoxal 5′-phosphate as a coenzyme.

The present disclosure provides a method for detecting L-serine based on cysteine desulfurase-containing living Escherichia coli cells, and belongs to the technical field of amino acid detection. The method includes the following steps: incubating an unknown sample with the cysteine desulfurase-containing living E. coli cells to produce a red substance, and qualitatively or semi-quantitatively detecting L-serine content in the unknown sample according to color changes of the red substance of the living E. coli cells, or quantitatively detecting L-serine content in the unknown sample by measuring absorbance of a lysate of the living E. coli cells. The detection method provided by the present disclosure is simple and convenient in process, few in reaction steps and stable in enzymatic activity of living cells.

The purpose of the present invention is to provide an organism having an ergothioneine productivity that is capable of easily producing ergothioneine within a short period of time at a high yield, as compared with a conventional technology, and, therefore, enables ergothioneine production on an industrial scale. This purpose can be achieved by a transformed fungus into which a gene encoding enzyme (1) or genes encoding enzymes (1) and (2) have been inserted and in which the inserted gene(s) are overexpressed. (1) an enzyme catalyzing a reaction of synthesizing hercynyl cysteine sulfoxide from histidine and cysteine in the presence of S-adenosyl methionine, iron (II) and oxygen. (2) An enzyme catalyzing a reaction of synthesizing ergothioneine from hercynyl cysteine sulfoxide using pyridoxal 5-phosphate as a coenzyme.

The purpose of the present invention is to provide an organism having an ergothioneine productivity that is capable of easily producing ergothioneine within a short period of time at a high yield, as compared with a conventional technology, and, therefore, enables ergothioneine production on an industrial scale. This purpose can be achieved by a transformed fungus into which a gene encoding enzyme (1) or genes encoding enzymes (1) and (2) have been inserted and in which the inserted gene(s) are overexpressed. (1) an enzyme catalyzing a reaction of synthesizing hercynyl cysteine sulfoxide from histidine and cysteine in the presence of S-adenosyl methionine, iron (II) and oxygen. (2) An enzyme catalyzing a reaction of synthesizing ergothioneine from hercynyl cysteine sulfoxide using pyridoxal 5-phosphate as a coenzyme.

The present invention relates to a novel thermophile-derived keratinase having keratin decomposition ability. Further, the present invention relates to a polynucleotide encoding the keratinase, a recombinant vector containing the same, host cells transformed by using the recombinant vector, and a method for preparing a keratinase including a step of culturing the host cells. Further, the present invention relates to a composition for decomposing keratin containing the enzyme; and a method for decomposing keratin by using the same. Further, the present invention relates to a keratin decomposed product decomposed by the enzyme. The keratinase according to the present invention rapidly and effectively decomposes hardly-decomposable keratin, and thus it is expected that the keratinase can be used for the effective treatment and the high value-added resource recovery of agricultural and livestock waste, which causes environmental problems (for example, a novel material for enzyme cosmetics), and can be used in an innovative enzymatic bioconversion technique utilizing various decomposition enzyme groups.

The present invention relates to methods and means for producing nitrogenase polypeptides in the mitochondria of plant cells.