苍白杆菌产生物表面活性剂的提取研究

该实验研究了苍白杆菌（Ochrobactrum sp.）所产生物表面活性剂的提取方法。对比了调pH法、溶剂萃取法和溶剂沉淀法的提取效果，并将调pH法与乙醇沉淀法相结合用来提取生物表面活性剂。结果表明，调pH法、溶剂萃取法不能将该生物表面化活性剂提取出来，而乙醇沉淀法可得到高乳化活性的产物。将发酵液的pH调至13除去沉淀后加入3倍体积冷乙醇进行提取，生物表面活性剂产量（6.69 g/L）是直接向原始发酵液加入3倍体积冷乙醇进行提取的1.45倍，该法可提取得到分子质量较大的含有少量糖、蛋白、脂及较多磷酸盐的生物表面活性剂。

Extraction of biosurfactants produced by Ochrobactrum sp.

The extraction methods of biosurfactants produced by Ochrobactrum sp. were studied. The extraction effects of pH adjustment method, solvent extraction method and solvent precipitation method were compared, and then the pH adjustment method and ethanol precipitation method were combined to extract biosurfactants. The results showed that the biosurfactant could not be extracted by the pH adjustment method and the solvent extraction method, and the ethanol precipitation method could obtain a product with high emulsification activity. The pH of the fermentation broth was adjusted to 13 to remove the precipitate, and then 3 volumes of cold ethanol was added for extraction, the yield (6.69 g/L) of biosurfactants was 1.45 times that of adding 3 volumes of ethanol to the original fermentation broth for extraction. The extraction method could obtain a large molecular mass biosurfactant containing a small amount of sugar, protein, lipid and more phosphate.