枯草芽胞杆菌BS501a复合诱变菌株及抗菌谱研究

Multiplex mutation isolates of Bacillus subtilis BS501a and the antimicrobial spectrum

[目的]通过复合诱变进一步提高枯草芽胞杆菌BS501a的生防效果。[方法]以BS501a为出发菌株,采用N+离子注入和60Coγ射线照射进行复合诱变。[结果]获得了5株拮抗活性提高的突变菌株。传代稳定性试验表明BSC45菌株经5次传代后拮抗稳定性仍保持在88.3%。该突变株各代与稻瘟病菌对峙培养拮抗带宽平均为7.5 mm,比出发菌株BS501a与稻瘟病菌对峙培养拮抗带宽6.05 mm提高了24%。采用对峙培养试验研究BSC45抗菌谱,发现BSC45仍保留了广谱拮抗活性。[结论]枯草芽胞杆菌突变株BSC45对多种真菌有抗菌作用,是一株很有潜力的生防菌株。

[Objective] To promote the biological control effects of Bacillus subtilis BSS01a by multiplex mutation. [Method] The initial antagonistic strain BSS01a was treated by N＋ ions implantation and 6o Co γ-irradiation. [Result] Five mutants were screened after multiplex mutation. Genetic stability of the mutant BSC45 remained to be 88.3% after being cultured for 5 generations. The average width of inhibition zones of the mutants against Magnaporthe grisea was 7.5 mm. There was a 1.24-fold increase as compared with the control strain BSS01a. The antimicrobial spectrum of BSC45 was studied using antagonistic experiments. The results showed that the mutant BSC45 had a broad-spectrum antagonistic activity. [Conclusion] The isolate Bacillus subtilis BSC45, with antagonistic activity to many different fungi, was a promising biocontrol isolate.