活性污泥和生物膜的胞外聚合物提取方法比较

The Comparison of Effectiveness of Different Methods in Extracting Extracellular Polymeric Substances(EPS) from Biofilm and Activated Sludge

采用加热法、NaOH法、硫酸法、阳离子交换树脂(CER)法、甲醛-NaOH法对3个污水厂的5种生物膜和活性污泥的胞外聚合物(EPS)进行提取实验研究,并以常规高速离心作为对照组.结果表明,不同的提取方法对同一种污泥的EPS各组分构成影响较大.一般情况下,提取总量按从多到少排列如下:NaOH法>加热法>甲醛-NaOH法>硫酸法>CER法>常规高速离心.其中,甲醛-NaOH法提取总量与加热法相近,但各组分的含量两者却有较大差别.甲醛的去除过程对EPS中组分的测定有干扰.NaOH法提取的EPS中DNA的含量远大于其他各种方法,通过甲醛-NaOH法的对比实验,可见NaOH法对细胞存在着一定的破坏.

Five commonly used extraction,including heating,NaOH,H2SO4,cation exchange resin（CER）,formaldehyde plus NaOH were selected to study their effectiveness in extracting extracellular polymeric substances（EPS） from five biofilm and activated sludge samples,using regular centrifugation as a control method.The results showed that the EPS content and the proportion of the components were strongly dependent on the extraction methods.The efficiency of the extraction methods,in decreasing order,for all sludge samples in general was： NaOH heating formaldehyde plus NaOH H2SO4CER regular centrifugation.The total EPS extracted by formaldehyde plus NaOH was similar to those extracted by heating,but the content of each components of EPS were quite different.The removal process of formaldehyde greatly affected the determination of the components of the EPS.The EPS extracted by NaOH constituted much more DNA than any other methods.Compared with the extraction results by formaldehyde plus NaOH,the NaOH method might cause cell lysis in some extent.