中文摘要：

从小麦根际土壤中分离得到一株对禾谷镰刀菌有拮抗作用的菌株7F1。以菌株7F1基因组总DNA为模板,通过16S rDNA和gyrB基因序列分析,鉴定7F1为多粘类芽孢杆菌。本实验对该菌种产拮抗物的稳定性进行了研究,同时,应用特异性引物对7F1中脂肽类抗生素合成相关基因进行检测。结果表明：该菌产生的拮抗物在40-90℃保持较高的活性;在蛋白酶K、胃蛋白酶和胰蛋白酶处理后,抑菌活性显著下降;在pH 3.0-10.0具有抑菌活性;使用已报道的脂肽类抗生素基因片段设计的引物进行聚合酶链式反应扩增,从该菌的基因组DNA中扩增得到了3种bamC、eriSa、ituC脂肽类抗生素合成酶基因。此研究结果对脂肽类抗生素进一步的分离提供了重要参考。

英文摘要：

A strain named 7F1 which showed strong inhibitory effect on Fusarium graminearum was isolated from rhizosphere soil of healthy wheat. Using its genomic DNA as the polymerase chain reaction（PCR） template, strain 7F1 was identified as Paenibacillus polymyxa by 16 S rDNA and gyrB sequence analysis. The stability of its antagonistic activity was evaluated and the detection of lipopeptide synthesis-related genes was conducted by using specific primers. The results showed that the antagonist produced by strain 7F1 had good heat stability, which could remain stable at 40–90 ℃. The inhibitory activity was markedly decreased by treatment with proteinase K, pepsin or trysin. The antagonist could exert its activity in the p H range from 3.0 to 10.0. Using previously reported lipopeptide primers, the lipopeptide synthase genes bamC, eriSa and ituC were successfully amplified by PCR from the genomic DNA of strain 7F1. These results may provide an important reference for further separation and application of lipopeptide.