伯氏嗜线虫致病杆菌娩norhabdus bovienii YL002对4种抗生素抗性突变株的筛选及抑菌活性分析

为了提高伯氏嗜线虫致病杆菌Xenorhabdus bovienii YL002抑菌活性,采用紫外线照射和吖啶橙复合诱变的方法,对其进行诱变改良,并在抗生素最小抑制浓度选择压力下筛选对4种抗生素具有抗性的突变菌株.以枯草芽孢杆菌为指示菌,得到了 17 株抑菌活性有显著变化且遗传稳定的突变菌株.其中菌株L0420-3对枯草芽孢杆菌的抑制活性最强,连续转接 5 次的抑菌圈直径增大率均在 80%以上;菌株Q025-1和L0314-4对番茄灰霉病菌菌丝生长的抑制率为 75.66%和 73.41%,分别是野生菌株的 1.35 倍和 1.31 倍;接种灰霉病菌后 5 d对番茄果实灰霉病的防效为 95.74%和 93.62%,分别是野生菌株的 1.71倍和 1.67 倍.

Inhibitive Effects ofXenorhabdus bovienii YL002 Mutants Resistant against 4 Antibiotics

Xenorhabdus bovienii YL002 isolated from entomopathogenic nematodes showed obvious antimicrobial activity. In order to improve the antimicrobial activity, authors mutated the strain by UV and acridine orange compound and obtained 17 mutants with higher antimicrobial activity and genetic stability. Among them, mutant L0420-3 showed the strongest inhibition effect on growth of Bacillus subtilis, mutants Q025-1 and Q025-2 showed significant improvement of the inhibitory rate against Botrytis cirerea with growth-inhibitory rates 75.66% and 73.41%, respectively, 1.35 times and 1.31 times higher than that of original YL002. The protective effects on tomato were 95.74% and 93.62% at 5 days after Botrytis cirerea inoculation, respectively, 1.71 and 1.67 times higher than that of YL002.