一株分离自海洋的细菌产表面活性剂的研究

A Study on One Biosurfactant-producing Bacterium Strain Isolated from the Ocean

从青岛近岸海域筛选到1株产胞外表面活性物质的菌株,可将发酵液的表面张力降至30.5 mN/m,经初步鉴定属于节杆菌属(Arthrobacter sp.)。薄层层析、红外光谱及色质联用分析结果表明,该菌株所产表面活性剂为糖脂类化合物,其化学组成为海藻糖和含β-羟基的十四及十六烷酸。该糖脂类生物表面活性剂具有良好的表面活性、乳化能力,其临界胶束浓度较低,为48.5 mg/L。通过摇瓶发酵实验确定其产表面活性剂的适宜条件为:葡萄糖为碳源,尿素为氮源,培养基初始pH为7.50,培养温度为35℃,培养时间为20 h。

A strain was isolated from offshore seawater of Qingdao and identified as Arthrobacter sp.This strain could produce a kind of extracellular surfactant,which could decrease the surface tension of the culture broth to 30.5 mN/m.The results of TCL,IR and GC-MS analyses showed that the biosurfactant was a sort of glycolipid composed of trehalose and two different fatty acids(β-hydroxy tetradecanoic acid and hexadecanoic acid containing).The trehalose lipid,whose critical micelle concentration(CMC) was as low as 48.5 mg/L,had a fine emulsification capacity and high surface-activity.The optimum conditions for its growth and production of biosurfactants were established as follows: glucose as carbon source,urea as nitrogen,initial culture pH value as 7.50,cultivation temperature as 35 ℃ and cultivation period as 20 h.