Production and partial characterization of bacteriocin-like pepitdes by Bacillus licheniformis ZJU12

SummaryBacillus licheniformis ZJU12, which was isolated from soil, could produce bacteriocin-like peptides that exhibited a broad spectrum of antagonistic activity against various species of Gram-positive bacteria and fungal pathogens, but not against Gram-negative bacteria tested except Xanthomonas oryzae pv. oryzae, a rice pathogen. The bacteriocin-like peptides were sensitive to proteinase K and trypsin. The activity was stable during temperature exposure up to 100 °C for 30 min, but lost completely at 121 °C for 15 min. The cell-free supernatant of B. licheniformis ZJU12 was shown to retain the activity within the pH range of 2–9, and the optimum pH for the activity was about 6.5. No adverse effect of the antagonistic compound to mice was observed in acute toxicity tests with the dose of 0.8 mg/20 g.