Optimization of antibacterial substance(s) produced by Bacillus subtilis BHHU100 and Bacillus amyloliquefaciens and its biocontrol activity against Erwinia amylovora [electronic resource].

Includes references.

Two isolates Bacillus subtilis BHHU 100 (M1) and Bacillus amyloliquefaciens (M2) were used for bioassay against the pathogenic bacterium Erwinia amylovora; the causal agent of fire blight disease in vitro using well-cut diffusion technique. These isolates showed high activity against the pathogenic bacteria, as well as, optimization of the produced antibacterial substance(s) from the two antagonistic isolates (M1, M2) was carried out. The effect of different characteristics was studied including media type, glucose concentrations, pH levels, incubation periods and temperature degrees on antibacterial substance(s) production. The optimum growth conditions for antibacterial substance(s) production by isolate M1 were obtained by growth on beef peptone glucose (BPG) medium supplemented with 2% glucose, pH 7.0 and incubation for 36 hrs at 30 ͦ C. However, growth on BPG medium supplemented with 1% glucose, pH 5.5 and incubation for 36 hrs at 36 ͦ C were the most suitable conditions for antibacterial substance(s) production by isolate M2. Our present study suggests that the economic importance of Bacillus subtilis BHHU 100 (M1) and Bacillus amyloliquefaciens (M2) could be applied economically as bio-control measures against fire blight disease in pear and apple orchards.

Summary in Arabic.

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