FIG. 3.

DNase activity of carocin S1 against genomic DNA from E. carotovora subsp. carotovora Ea1068. (A) Analysis of the killing activity of purified carocin S1. Carocin S1 was purified from 89-H-4 (1), H-rif-8-6 (2), TH22-10/pAYL4 (3), and Ea1068/pAYL4 (4) strains and then added to the indicator plates to test its killing activity. The indicator strains were Ea1068/pAYL4 in the left plate and Ea1068 in the right plate. (B) The reaction mixture (50 μl) containing 1 μg of DNA and 20 μl of sample solution in 10 mM Tris, pH 7.5, 4 mM MnCl₂ was incubated at 28°C for 2 h. Samples 1 to 5 were collected from Ea1068, and samples 6 to 10 were collected from Ea1068/pAYL4. Lanes 1 and 6 were from the 11th fraction tubes, lanes 2 and 7 from the 12th fraction tubes, lanes 3 and 8 from the 13th fraction tubes, lanes 4 and 9 from the 14th fraction tubes, and lanes 5 and 10 from the 15th fraction tubes. Lane 11 was genomic DNA isolated from Ea1068. Lane 12 was the positive control (DNA mixed with EcoRI and buffer), and lane 13 was the negative control (DNA and buffer). Samples were treated and analyzed by agarose gel electrophoresis.