发酵碳源对铜绿假单胞菌NY3所产鼠李糖脂结构及性能的影响

Effects of fermentation carbon sources on structure and properties of rhamnolipid produced by Pseudomonas aeruginosa NY3

为研究发酵碳源对铜绿假单胞菌NY3所产鼠李糖脂结构及性能的影响,从鼠李糖脂的结构组分、性能和应用效果等方面展开研究。薄层实验证明两种鼠李糖脂均含有单糖脂和双糖脂。液质分析发现以橄榄油作碳源时,鼠李糖脂中双糖脂(Rha-Rha-C5-C6:1和Rha-Rha-C8-C8:2)比例更大,约为73.09%。而地沟油作碳源时,单糖脂(Rha-C10-C10和Rha-C16-C16:2)的比例更高,约为76.91%。橄榄油和地沟油为碳源的鼠李糖脂的临界胶束浓度(CMC)分别为55 mg/L和80mg/L。相同投加量时,前者乳化性和乳化稳定性均优于后者。NY3菌降解含油污泥时,投加双糖脂含量高的鼠李糖脂会使C16-C30直链烷烃的去除率更高。

The effects of fermentation carbon sources on the structure,properties of rhamnolipid produced by strain Pseudomonas aeruginosa NY3 were investigated. Two spots with different size and color shade on the plate of thin layer chromatogram（ TLC） indicated that the rhamnolipid contained at least two different components, including monorhamnolipids and dirhamnolipids. The detection results of liquid chromatography hybrid ion trap time-of-flight mass spectrometry（ LC-IT-TOF/MS） revealed that the proportion of dirhamnolipids（ Rha-Rha-C5-C6： 1,Rha-Rha-C8-C8： 2）in the produced rhamnolipid mixture with olive oil as the fermentation carbon source could reach to about 73. 09%. While with the swill-cooked dirty oil as carbon source,the percentages of dirhamnolipids（ Rha-C10-C10,Rha-C16-C16： 2） was only about 23. 09%. The critical micelle concentration（ CMC） of the former and the latter rhamnolipid mixtures were 55mg/L and 75 mg/L,respectively. At the same concentration,the higher proportion of the dirhamnolipids resulted in the better of the emulsifying property and emulsion stability. The rhamnolipid with higher content of dirhamnolipids had an obvious promoting effects for the removal of C16 ~ C30 alkanes by the degradation of strain NY3 under liquid treatment condition（ oil content was 9. 6%）.