生物表面活性剂合成条件的优化及提取方法

利用油平板筛选法和排油圈法从辽河某油田的土壤样品中分离筛选高效的生物表面活性剂产生菌, 通过16S rRNA基因序列分析对所筛选菌株进行鉴定。采用L16(45)正交实验对所筛选菌株合成生物表面活性剂的条件进行优化。比较5种提取方法对发酵液中生物表面活性剂的提取效果。共分离得到17株菌,其中菌株A3、As和Y产表面活性剂的能力最强。16S rRNA基因序列分析表明,这3株菌均为假单胞菌属(Pseudomonas)。菌株A3、As、Y和 A3-As混合菌的生物表面活性剂提取量较优化前有明显的提高,其产量分别是优化前的8.4倍、6.4倍、5.6倍和5.7倍,其中,菌株As的生物表面活性剂产量最高,可达20.55 g/L。对于3种纯菌和A3-As混合菌而言,5种提取方法中均以CHCl3萃取的量最高;而对其他混合菌,5种提取方法的差别并不显著。菌株A3、As、Y均属于高效的生物表面活性剂产生菌,具有很好的应用前景。

Optimization of biosurfactants synthesis conditions and extraction methods

Using Liaohe oilfield soil samples, efficient biosurfactant-producing bacteria were isolated by the plate screening method and the repulsion oil method. Strains were identified based on the 16S rRNA gene sequence analysis. Biosurfactant synthesis conditions were optimized using L16(45) orthogonal experiments for the screened stains. Five extraction methods for surfactants from fermentation broth were compared. A total of 17 strains were isolated, and strains A3, As, and Y had better surfactant production ability than did the other strains. They were identified as Pseudomonas. The amount of biosurfactant extracted after optimization increased significantly in strain A3 (by 8.4 times), strain As (by 6.4 times), strain Y (by 5.6 times), and A3-As (by 5.7 times). The highest surfactant yield of 20.55 g/L was obtained for strain As. For the three pure bacteria and the mixed strain A3-As, the CHCl3 extraction method was optimal with respect to biosurfactant extraction quantity. However, for the other mixed strains, the difference among the five methods was not significant. Strains A3, As, and Y are efficient biosurfactant-producing among and have many potential applications.