Abstract
Five micrograms per milliliter of aristeromycin, a nucleoside antibiotic, completely inhibited the growth of Xanthomonas oryzae at all growing stages. When cells of Xanthomonas oryzae were treated with the antibiotic at the beginning of cultivation and transferred to a growth medium without antibiotic, the lag phase was prolonged without the change in the length of the log phase. Incubation of Xanthomonas oryzae with the antibiotic, reduces the viable cell count without affecting the optical density of the cell suspension. It was assumed that aristeromycin inhibited the growth of Xanthomonas oryzae by its bacteriocidal action. Ten to a hundred-fold mounts of either of adenosine, adenine, deoxyadenosine and inosine reversed the growth by aristeromycin. Complete reversal of the cell growth was not seen in the presence of these compounds because of their own growth inhibitory activity. Adenosine exhibited the strongest competitive activity with the antibiotic. It was suggested that the antibiotic acted on the metabolic pathway of adenylic acid, adenosine and adenine.
