Six gram negative bacterial strains producing lactate oxidase were screened from 50 bacterial strains isolated from soil. The strains were capable of producing lactate oxidase both in shaking and static culture. Lactate oxidase activity was highest in strain KY6 and this strain was chosen as the enzyme source. The crude extract of strain KY6 containing 1.29 g of protein per liter converted DL-lactate (90 mM) to pyruvate yielding 61.8% in 12 h, which corresponds to a space-time yield of 86.5 mol l(-1) d(-1) g(-1) of cell-free protein. Morphological and physiological studies according to Bergey’s Manual of Systematic Bacteriology revealed that the bacterial strain KY6 belongs to the Edwardsiella tarda Biogroup 1.