ABSTRACT
Over use of chemical pesticides causes several environmental problems and thus, the use of biological control agents has drawn attention and has been considered as a promising alternative to chemical pesticides. Therefore, the integrated use of chemical pesticides and microorganisms may be one of the practical methods applicable in the field. Some attempts of the integrated use of biological agents and chemical pesticides have been reported. Bacillus subtilis RB14-C is a spontaneous streptomycin-resistant mutant of strain RB14 and is a coproducer of antifungal substances, iturin A and surfactin. The growth rate and the antifungal activity of RB14-C were the same as those of the parent strain RB-14. The functional mechanism of flutolanil against plant pathogens was speculated to be an inhibitory effect on the activity of succinate dehydrogenase of plant pathogens. Therefore, the reduction in the surfactin production in the presence of flutolanil may be partly related to a similar inhibitory effect on B. subtilis.
