| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new formaldehyde oxidase capable of acting on formaldehyde but not acting on acetaldehyde, excellent in substrtte specificity by catalyzing a specific reaction, and capable of quantitatively determining a material in a live specimen in high sensitivity and reproducibility. SOLUTION: This formaldehyde oxidase acts on formaldehyde but does not act on acetaldehyde, catalyzes the reaction forming formic acid and hydrogen peroxide by oxidizing the formaldehyde in the presence of water and oxygen, and has the following physicochemical properties: optimum pH: 8.0-9.5; stable pH: 7.0-9.0; thermal stability: up to 55 deg.C; acting optimum temperature: about 50 deg.C; influence of inhibitor: inhibited by copper sulfate, NH2 OH, sodium azide and p-mercuribenzoic acid; molecular weight: 310,000 having subunit of 78,000. The formaldehyde oxidase is obtained by culturing microorganisms such as Cylindrocarpon didymum (FERM BP-5758), etc., belonging to the genus Cylindrocarpon and having the before oxidase-producing ability in a medium. |
