一株枯草芽孢杆菌的鉴定和抑菌作用研究

Identifiction of Bacillus subtilis and the Inhibitory Effect on Pathogenic Fungi

为明确一株具有生防作用的细菌种类及对几种病原真菌的抑制作用,通过16SrDNA序列分析对菌株进行鉴定,采用平板对峙法研究其发酵液、无菌培养滤液和细胞破碎液的抑菌活性,设计不同温度处理、设置不同pH环境和不同pH处理来探究该菌的抑菌效能。结果表明:供试菌株为枯草芽孢杆菌,命名为KC-1,该菌株的发酵液对禾谷镰刀菌、镰孢菌、玉米链格孢、稻梨孢、尖孢镰刀菌均有显著的抑制作用,对镰孢菌的抑制率最高,可达74.39%;抑菌活性物质不耐热,在100℃处理30 min后,发酵液对病原真菌无明显抑制作用;细胞破碎后仍然具有抑菌作用,KC-1菌体破碎液稀释1.0×10^4倍及pH5~10的条件下仍具有稳定的抑菌活性。KC-1菌具有高效、广谱的抑菌活性,对病原真菌的拮抗作用效果明显,有一定的应用价值。

In order to determine the bacterial species with the biological control effect and the inhibitory effect on several kinds of pathogenic fungi,the bacterial strain was identified by the 16SrDNA sequence analysis,and the fermentation broth,aseptic culture filtrate and cell fragmentation solution was studied by the plate confrontation method.Different temperature treatment,different pH environment and different pH treatment were designed to explore the antibacterial efficacy of the bacteria.The results showed that the tested strains was identified as Bacillus subtilis,named KC-1,the KC-1 fermentation broth has a significant inhibitory effect on Fusarium graminearum,Fusarium spp.,Maize Alternaria tenuis Nees,Piricularia oryzae and Fusarium oxysporum,and the inhibition ratio of Fusarium spp.was as high as 74.39%;The antibacterial active substances were not thermolabile,the fermentation broth had no obvious inhibitory effect on pathogenic fungi after the treatment at 100℃for 30 minutes;it still had antibacterial effect after cell being fragmented,the KC-1 bacteria fragmentation solution still had a stable antibacterial activity after being diluted 10^4 times and at a pH level of 5-10.The KC-1 bacteria with the high efficiency and the broad-spectrum antibacterial activity has obvious antagonistic effect on pathogenic fungi and considerable applied value.