Characterization of Bacillus subtilis YB8, coproducer of lipopeptides surfactin and plipastatin B1.

Biological control of soilborne plant pathogens by antagonistic microorganisms offers a practical supplement or alternative to many disease management strategies that depend heavily on chemical pesticides. We have isolated Bacillus subtilis YB8 from a bark compost as a suppressive bacterium against phytopathogenic fungi (I1). The number of this bacterium in the compost was 1.3 X 106 (cfu/g dry solid) and this was one to two orders higher than those of other bacteria from different suppressive composts (11). The higher stability observed in the natural environment will be a suitable characteristic when this bacterium is used as a biological pesticide.