铜绿假单胞菌S6分泌的生物表面活性剂特性

研究了1株铜绿假单胞菌S6(Pseudomonas aeruginosa S6)分泌的生物表面活性剂的理化性质.该生物表面活性剂的临界胶束浓度为50mg·L-1,此时其表面张力为29.3mN·m-1.pH值对S6产表面活性剂有一定影响,在中性及弱碱性条件下,S6长势较好且表面活性剂表面张力较低.该生物表面活性剂对菲具有非常明显的增溶效应,使水中菲的溶解度增加了约23倍.原油的加入有利于S6产表面活性物质.与原油的相互作用说明该生物表面活性剂能够乳化原油且维持乳化液稳定性于80%以上;原油浓度为6%～8%时,能达到最佳乳化效果.HPLC-ESI-MS分析检出该生物表面活性剂含有13种鼠李糖脂同系物.

Characteristics of a biosurfactant produced by Pseudomonas aeruginosa S6

The physicochemical characteristics of a biosurfactant excreted by Pseudomonas aeruginosa S6 were studied. The Critical Micelle Concentration (CMC) of this biosurfactant was 50 mg·L-1, while its surface tension was 29.3 mN·m-1. The pH affected the production of the biosurfactant. Strain S6 grew well under neutral and alkaline conditions, and the surface tension was relatively low in this pH range. The biosurfactant increased the solubility of phenanthrene in water by about 23 times compared with control. Addition of crude petroleum favored the production of surface-active substances. Emulsification experiments indicated that the biosurfactant could effectively emulsify crude petroleum, producing an emulsion with a stability of over 80%. The emulsification efficiency was highest when the concentration of crude petroleum was 6%~8%. HPLC-ESI-MS analysis revealed that this biosurfactant contained 13 rhamnolipid congeners.