一株表面活性剂产生菌的筛选及其特性研究

Isolation and Characteristics of Biosurfactant-producing Microorganism

摘要:

从氧化沟含油污水中分离得到1株能产生物表面活性剂菌株S₆(Pseudomonas sp.)，经生理生化实验和16S rDNA序列分析鉴定，S₆为铜绿假单胞菌。红外光谱分析得知S6在代谢过程中能够产生糖脂类表面活性物质。其临界胶束浓度(CMC)为50mg/L,可将水的表面张力由72mN/m降到33.9mN/m。发酵液的表面张力和排油直径的测定结果显示发酵液在不同的盐度、pH和溶解氧量条件下,具有较稳定的表面活性。通过正交实验确定了优化培养基条件为葡萄糖10g、尿素5g、磷酸二氢钾1g、微量元素液2mL、pH 8.0、水1000mL；S₆在优化培养基中合成生物表面活性剂的产量为0.173g/L。

Abstract:

A biosurfactant-producing strain (S₆) was isolated from oil-containing wastewater in oxidation ditch and identified as Pseudomonas aeruginosa based on physiological and biochemical experiments and 16S rDNA sequence analysis. Infrared spectrum analysis revealed that S₆ produced glucolipid in the process of metabolism. It was observed that S₆ decreased the surface tension of water from 72 mN/m to 33.9 mN/m with the critical micelle concentration (CMC) of 50mg/L. The measurement of oil displacement and surface tension demonstrated that the fermented liquid had stable surface activity at varying range of salinity, pH, amount of dissolved oxygen. The optimal culture condition was obtained through orthogonal experiment: glucose 10g/L, urea 5g/L, KH₂PO₄ 1g/L, liquor of microelement 2mL, pH 8.0, water 1000mL; and the biosurfactant production under optimal culture condition was 0.173g/L.