生物表面活性剂产生菌的分离及其产物性质的研究

Study on Isolation and Properties of the Product of a Strain of Biosurfactant Bacterium

从油井附近长期被石油污染的表层土壤中分离且富集菌株,然后用蓝色凝胶平板法获得单菌落,通过排油圈法和发酵液表面张力的测定选出排油圈直径最大和表面张力最小的菌,编号为B-6。经过生理生化试验和16S r DNA序列的测定,从而确定B-6菌株为铜绿假单胞杆菌(pseudomonas aeruginosa)。为了使B-6菌株能够产生更多的生物表面活性剂,进行培养优化实验,研究表明,最优的培养条件是碳源为豆油、氮源为硝酸钠、温度为28℃、pH为7.0以及培养时间为2天。在最优的培养条件下,测得B-6菌株的发酵液的表面张力由原来的29.4 m N/m下降为26.5 m N/m。提取B-6菌株产生的表面活性剂,用红外色谱法、薄层层析法综合确定B-6菌产生的生物表面活性剂为糖脂。

Strains are separated and enriched form the soil which is long-term contaminated by oil form the well near the surface. And then single colony is obtained through the blue gel slab method. B-6 is selected through a discharge of oil ring method and fermented liquid surface tension measurement, which possesses the largest oil discharge circle diameter and the lowest surface tension. After physiological and biochemical experiments and 16 s r DNA sequence determination, thus B-6 strain is determined for pseudomonas aeruginosa.Operating culture conditions optimization experiment of B-6 bacteria, the results showed that the optimum culture condition is carbon source for soybean oil, nitrogen source for sodium nitrate, temperature 28 ℃, pH=7.0 and incubation time for 2 days. Under the condition of the optimal cultivation, measured the surface tension of the fermented liquid is 26.5m N/m.Extracting of B-6 strains of surfactant, use infrared chromatography and thin-layer chromatography methods to determine that the biosurfactant of B-6 bacteria producer is sugar ester.