[Studies on the lactate oxidase producing conditions by Edwardsiella tarda]

A bacterium producing lactate oxidase was re-screened from five strains based on previous researches. The lactate oxidase activity was the highest in strain L1 and this stain was chosen as the enzyme source. Morphological and physiological studies revealed that the bacterial strain L1 belongs to the Edwardsiella tarda Biogroup I. This stain is different from the reported strains Mycobacterium and Pediococcus, which produce lactate oxidase. The enzyme producing conditions were studied in shaking cultures, and the effects of initial pH, riboflavin, lactate and ammonia sulphate concentrations on the production were carried out respectively. The bacteria resource of enzyme is significant to pyruvate production by enzymatic method, and to the enzyme assay of lactate for medical diagnosis, and the application of enzyme electronic probe.