[Analysis of nonenzymic source of superoxide anion in pathogenic Xanthomonas oryzae pv. oryzae].

With electron spin resonance and chemical assay, the production of superoxide anion in the Xanthomonas oryzae pv. oryzae strain OS-14 suspension is extracellularly localized. It was found that superoxide anion produced in the filtrate. It was confirmed that peptide or enzyme did not contribute to the production of superoxide anion in the filtrate of OS-14. Organic acids were shown to be the primary source of superoxide anion produced in the filtrate of OS-14. These results indicated that non-enzymic molecules might be another source of superoxide anion produced by Xanthomonas oryzae pv. oryzae, in addition to enzymes, which suggested the multiform generation of superoxide anion.