Abstract: The present invention encompasses: [1] a DNA encoding the protein of any one of (i) a protein comprising the sequence of SEQ ID NO:1; (ii) a protein comprising a sequence with one to ten amino acid deletions, substitutions, or additions in the sequence of SEQ ID NO:1, and having fructosyl peptide oxidase activity; (iii) a protein comprising a sequence having 99% or higher homology to the sequence of SEQ ID NO:1, and having fructosyl peptide oxidase activity; and (iv) a protein having fructosyl peptide oxidase activity, which is encoded by an expression plasmid harbored by the strain deposited under Accession No. FERM BP-11026; [2] a DNA comprising the of SEQ ID NO: 2; and [3] a DNA that hybridizes under stringent conditions with a DNA comprising a sequence complementary to SEQ ID NO: 2, where the DNA encodes a protein having fructosyl peptide oxidase activity.