To provide a gene useful for imparting oxygen resistance to a microorganism and use of the gene. The oxygen-resistance-imparting gene encoding a protein selected from among the following proteins (a) to (c): (a) a protein having the amino acid sequence of SEQ ID NO: 2 or 6； (b) a protein which has an amino acid sequence equivalent to the amino acid sequence of (a), except that one to several amino acid residues are deleted, substituted, or added, and which exhibits oxygen-resistance-imparting activity； and (c) a protein which has an amino acid sequence having an identity of 85% or higher to the amino acid sequence of (a), and which exhibits oxygen-resistance-imparting activity.
