Lactococcus lactis subsp. cremoris IFO3427 produced both a well-characterized lactate dehydrogenase and a lactate oxidase. The lactate oxidase gene, designated loxL, was cloned and almost 200-fold overexpressed in Escherichia coil compared to the wild-type strain. The nucleotide sequence of loxL gene, composed of 1,101 bp and 367 amino acid residues, was also determined. The primary structure of LoxL was highly homologous to those of several alpha-hydroxyacid oxidases. LoxL was purified from the recombinant strain and characterized. Properties of the purified enzyme were similar to those of the Aerococcus viridans lactate oxidase.