假单胞菌O-2-2利用油脂废水生产鼠李糖脂研究

Study on rhamnolipid production from refined vegetable oil wastewater by Pseudomonas sp.O-2-2

通过摇瓶培养试验,研究了铜绿假单胞菌O-2-2以植物油精炼废水为原料生产鼠李糖脂生物表面活性剂的适宜条件.结果表明以NaNO3为氮源,碳氮比为15,培养基初始pH值为7.5,32℃,250 r/min培养84 h,鼠李糖脂产量最高,达2.14g/L.液-质联用分析结果表明所提取的糖脂由11种同系物组成,都含有1～2个的鼠李糖和1～2个含β-羟基的碳链长度为8～12的饱和或不饱和脂肪酸.该糖脂生物表面活性剂的临界胶束浓度为69.5 mg/L,可将水的表面张力降至29.2 mN/m,并具有良好的耐温耐盐性.

The optimal conditions of flask culture for rhamnolipid biosurfactant production from refined vegetable oil wastewater were studied through Pseudomonas aeruginosa strain O-2-2.The maximal rhamnolipid concentration of 2.14 g/L can be reached when the strain is incubated for 84 h at such conditions:NaNO_3 as nitrogen source,15 of C/N ratio,7.5 of initial pH value,at 32℃ and 250 r/min of shaking rate.Totally 11 rhamnolipid homologs,being formed by one or two rhamnose molecules linked to one or two β-hydroxy fatty acids of saturated or unsaturated alkyl chain between C_8 and C_(12),were isolated and identified from the glycolipid mixture by HPLC-ESI-MS.The critical micelle concentration of the rhamnolipid biosurfactant was 69.5 mg/L.It can lower the water surface tension to 29.2 mN/m and keep its surface activity at high temperature or in high-salinity solution.