Characteristics ofBacillus subtilisisolated from composts suppressing phytopathogenic microorganisms

Transformation of Bacillus subtilis, antifungal-antibiotic iturin producers with isolated antibiotic resistance plasmids.

“…As a recipient strain for plasmid screening, B. subtilis MI 113 (arg-15 trpC2 hsmM hsrM), which is a derivative of B. subtilis Marburg 168, was used. B, subtilis NB22, UB24, YB8 (19,20), and RB 14 (this work) are iturin-producing strains originally isolated from different composts in this laboratory. These four bacterial strains were different from each other in the degree of suppressiveness to plant pathogens and in cultural characteristics (20).…”

“…B, subtilis NB22, UB24, YB8 (19,20), and RB 14 (this work) are iturin-producing strains originally isolated from different composts in this laboratory. These four bacterial strains were different from each other in the degree of suppressiveness to plant pathogens and in cultural characteristics (20). Plasmid pC 194 (7) which is specified by the resistance to chloramphenicol was used as a control plasmid.…”

“…Although intensive work has been carried out on the biochemistry of peptide antibiotics, there is little knowledge of their genetics (12). The antibiotic iturin can be a model for the study of secondary metabolism because of its unique structure and its broad suppressibility to phytopathogens (19,20). One important limiting factor in genetic studies with iturin producers has been the lack of efficient, rapid, and reliable techniques for introducing exogenous DNA into cells, especially into wild strains.…”

“…We have demonstrated that several strains of Bacillus subtilis isolated from composts showed broad suppressive spectra on various plant pathogens by producing an antibiotic, iturin extracellularly (19,20). These iturin-producing strains can be candidates of biological control agent to minimize the use of chemical pesticides (19)(20)(21).…”

“…These iturin-producing strains can be candidates of biological control agent to minimize the use of chemical pesticides (19)(20)(21).…”