Biochemical variation among isolates of Xanthomonas oryzae pv. oryzae causing bacterial leaf blight in rice

Xanthomonas oryzae pv. oryzae is an important and destructive pathogen causing bacterial leaf blight in rice. Attempt were made to ascertain the variability in Xanthomonas oryzae pv. oryzae and five isolates collected from different locations showed biochemical variations. The tests conducted to know the biochemical properties, among the five isolates of X. oryzae pv. oryzae subjected for biochemical studies, all the isolates showed positive reaction for gelatin liquefaction, protein digestion, catalase test, KOH test, ammonia and hydrogen sulphide production. Isolates Xoo1, Xoo2 and Xoo3 showed positive reaction for starch hydrolysis. However, all the isolates showed negative reaction for indole production, voges-proskaure test, nitrate reduction, methyl red test and production of fluorescent pigment on King’s B medium.