In summary, our results support the view that difficidin and bacilysin are the main X. oryzae pv. oryzae and X. oryzae pv. oryzicola suppressing compounds in the culture filtrate of B. amyloliquefaciens FZB42. These strains are the causative agents of the important rice diseases bacterial blight and bacterial leaf streak, respectively. Since difficidin and bacilysin have not been previously used in agricultural management, this finding provides a potential option to use them or their producer strain FZB42 as an alternative to chemical bactericides to control rice diseases.