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【目的】研究分离得到的表面活性剂产生菌的产表面活性剂能力、分类地位和抑菌活性。【方法】采用血平板、油平板进行表面活性剂产生菌的分离,以排油圈法进行表面活性的测定;通过生理生化特性和16S rDNA序列相似性分析对BS1菌株进行初步鉴定;利用对峙培养法和菌丝生长、孢子囊形成、孢子萌发的抑制率测定研究其抑菌活性。【结果】从石油污染土壤中分离到的BS1菌株可产生表面活性剂,在分类学地位上属于假单胞菌属(Pseudomonas sp.)。BS1菌体、发酵上清液、挥发性物质对12种供试病原真菌均表现出一定的抑制作用。BS1菌体、发酵上清液对大豆疫霉菌(Phytophthora sojae)的抑制率最大,分别达到65.31%和95.93%。发酵上清液通过影响大豆疫霉菌菌丝生长、孢子囊形成、孢子萌发等方式抑制病原菌的正常生长,稀释20倍的发酵上清液依然具有明显的抑制作用。BS1菌株产生的挥发性物质对大豆菌核菌(Sclerotinia sclerotiorum)的抑菌效果最好,抑制率达到84.25%。【结论】BS1菌株在产生表面活性剂的同时,还具有生物防治作用潜力。
【Objective】 The purpose of this study was to investigate the surfactant-producing ability, taxonomic status and antibacterial activity of the surfactant-producing bacteria. 【Method】 Isolation of surfactant-producing bacteria was carried out by using blood plate and oil plate, and the surface activity was determined by oil drain circle method. The BS1 strain was initially identified by physiological and biochemical characteristics and 16S rDNA sequence similarity analysis. Law and mycelium growth, sporocyst formation, spore germination inhibitory rate determination of its antibacterial activity. [Results] The BS1 strain isolated from petroleum-contaminated soils produced surfactant and, in a taxonomic position, belongs to the genus Pseudomonas sp. BS1 bacteria, fermentation supernatant, volatile substances on the 12 kinds of pathogenic fungi showed some inhibition. The inhibition rate of BS1 strain and fermentation supernatant to Phytophthora sojae was the highest, reaching 65.31% and 95.93% respectively. The fermentation supernatant inhibited the normal growth of pathogenic bacteria by affecting mycelium growth, sporocyst formation and spore germination of Phytophthora sojae, and the fermentation supernatant with 20-fold dilution still had obvious inhibitory effect. The BS1 strain produced the best bacteriostasis against Sclerotinia sclerotiorum with the inhibition rate of 84.25%. 【Conclusion】 The strain BS1 has the potential of biological control while generating surfactant.