中文摘要：

枯草芽孢杆菌菌株B11对广泛的植物病原真菌和细菌都具有拮抗作用。以柯斯质粒pWEB：：TNC为载体构建了枯草芽孢杆菌菌株B11的基因文库，文库含9000个克隆。文库克隆中插入的DNA片段平均为42．1kb．该文库含有菌株B11基因组中任一基因的概率为99．99％。采用平板活性检测法筛选文库，筛选到1个对茄青枯假单胞菌菌株P13具有拮抗活性的文库克隆GXN9527，该克隆的重组质粒pGXN9527含有50kb的菌株B11的DNA。文库克隆对革兰氏阴性植物病原细菌如水稻黄单胞菌水稻变种也具有拮抗活性，而对革兰氏阳性细菌如地衣芽孢杆菌和植物病原真菌如尖孢镰刀菌西瓜专化型、立枯丝核菌、水稻稻灰梨孢菌则没有拮抗活性。分别含有pGXN9527的18、12、9、8kbBamH I片段的亚克隆对P13均没有拮抗活性，说明编码该拮抗物质的生物合成基因很可能成簇存在。

英文摘要：

Bacillus subtilis strain B11 displayed antagonistic activity against a wide variety of plant pathogenic fungi and bacteria. A genomic library of the strain Bll containing 9 000 clones was constructed. The average size of the inserted DNA in recombinant plasmids was 42.1 kb and the probability of harboring any gene in the genome of the strain Bll was 99.99%. The library was screened for antagonistic activity against Ralstonia solanacearurn strain P13 and a clone carrying a 50 kb inserted DNA was isolated, which was designated as GXN9527. Plate assay showed that the GXN9527 could inhibit the growth of plant pathogenic Gram-negative bacterium Xanthomonas oryzae pv. oryzae, but not inhibit the Gram-positive bacterium Bacillus licheniformis or the phytopathogenie fungi Fusarium oxysporum f. sp. niveum, and Rhizoctonia solani. The subclone containing an individual 18 kb, 12 kb,9 kb or 8 kb BamH I fragment of pGXN9527 did not exhibit antagonistic activity against strain P13, indicating that genes involved in biosynthesis of antagonistic substance （s） might be clustered.