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枯草杆菌(Bacillus subtilis)B034是从水稻叶面分离的植物病原细菌拮抗菌,对水稻白叶枯病菌,水稻细条病菌有较强的抑制作用。(NH_4)_2SO_4饱和沉淀粗提液经Sephadex G—100柱层析所得的3个洗脱吸收峰中有两峰具较强的抑菌活性。此拮抗物抗热,对胰蛋白酶敏感,对蛋白酶K、E部分敏感。 B034菌株内含有一稳定的大小约8kb的内源质粒。质粒消除后,其拮抗活性也随之消失。用穿梭质粒pMK4的XL1—Blue中对其EcoR Ⅰ酶切4片段分别进行了克隆,并转化到无拮抗活性的Bacillus DB104中,片段Ⅱ+Ⅲ显示了部分的拮抗活性。
Bacillus subtilis B034 is a phytopathogenic bacterial antagonist isolated from the leaf surface of rice and has a strong inhibitory effect on bacterial leaf blight and bacterial pathogen of rice. (NH_4) _2SO_4 saturated precipitation crude extract by Sephadex G-100 column chromatography obtained three peak absorption peaks with strong antibacterial activity. This antagonist is resistant to heat, is sensitive to trypsin, and is partially sensitive to protease K, E. The B034 strain contained a stable endogenous plasmid of about 8 kb in size. Plasmid elimination, the antagonistic activity also disappeared. The four fragments of EcoR Ⅰ digested with XL1-Blue of shuttle plasmid pMK4 were respectively cloned and transformed into non-antagonistic Bacillus DB104. Fragment Ⅱ + Ⅲ showed partial antagonistic activity.