In enzymology, a choline oxidase (EC 1.1.3.17) is an enzyme that catalyzes the chemical reaction choline + O2↔ betaine aldehyde + H2O2. Thus, the two substrates of this enzyme are choline and O2, whereas its two products are betaine aldehyde and H2O2.https://www.creative-enzymes.com/product/Native-Arthrobacter-Globiformis-Choline-Oxidase_735.html