A mutant glycine oxidase is obtained by substituting at least one wild-type amino acid sequence derived from thermophilic bacteria belonging to the family Bacillus with another amino acid, and has the following enzyme properties. Molecular weight: 40,000±2,000 daltons by SDS-PAGE. Optimum temperature: 45° C. under the condition of pH 8.5 in presence of pyrophosphate. Optimum pH: pH 8.0 under the condition of 37° C. in presence of pyrophosphate. Thermal stability: Stable up to 70° C. under the condition of pH 8.5 while retaining for 1 hour in presence of pyrophosphate. pH Stability: Stable in the range of pH 5.5 to 10.0 under the condition of 4° C. while retaining for 24 hours in presence of pyrophosphate. Specific activity: 1.2 units/mg or more. Kinetic constant K.sub.m: 0.2 mM or less.

A mutant glycine oxidase is obtained by substituting at least one wild-type amino acid sequence derived from thermophilic bacteria belonging to the family Bacillus with another amino acid, and has the following enzyme properties. Molecular weight: 40,000±2,000 daltons by SDS-PAGE. Optimum temperature: 45° C. under the condition of pH 8.5 in presence of pyrophosphate. Optimum pH: pH 8.0 under the condition of 37° C. in presence of pyrophosphate. Thermal stability: Stable up to 70° C. under the condition of pH 8.5 while retaining for 1 hour in presence of pyrophosphate. pH Stability: Stable in the range of pH 5.5 to 10.0 under the condition of 4° C. while retaining for 24 hours in presence of pyrophosphate. Specific activity: 1.2 units/mg or more. Kinetic constant K.sub.m: 0.2 mM or less.

The invention provides a genetically modified bacterium for production of thiamine; where the bacterium is characterized by a transgene encoding a thiamine monophosphate phosphatase (TMP phosphatase having EC 3.1.3.-) as well as transgenes encoding polypeptides that catalyze steps in the thiamine pathway. The genetically modified bacterium is characterized by enhanced synthesis and release of thiamine into the extracellular environment. The invention further provides a method for producing thiamine using the genetically modified bacterium of the invention; as well as the use of the genetically modified bacterium for extracellular thiamine production.

The present invention provides a novel enzyme and methods of using the enzyme for measuring glycine concentration. Specifically, the present invention provides an enzyme in which at least one amino acid residue is mutated so as to improve a property of a glycine oxidase which is associated with the measurement of glycine (e.g., activity of glycine oxidase for glycine, thermal stability of glycine oxidase, and substrate specificity of glycine oxidase for glycine,); and a method of analyzing glycine, that includes measuring glycine contained in a test sample using the modified enzyme; and the like.

At least the presence of a starting material is detected by measuring glycine formed as a by-product along with a main product through a chemical reaction involving hippuric acid and/or methylhippuric acid as the starting material and catalyzed by a hydrolase. The hydrolase is an aminoacylase having an amino acid sequence of SEQ ID NO: 1 or a protein having the amino acid sequence of SEQ ID NO: 1 in which one or more amino acids are deleted, replaced, or added and having activity for hydrolysis of the hippuric acid and the methylhippuric acid.

The present disclosure relates to a genetically modified host cell having improved production of thiamine, wherein the host cell expresses one or more heterologous ThiO enzymes converting glycine into dehydroglycine (DHG) in the host cell and/or one or more heterologous ThiI enzymes catalyzing the transfer of sulfur from IscS to the sulfur carrier protein ThiS in the host cell, whereby the production of the thiamine in the genetically modified host cell is improved compared to an unmodified parent host cell.