Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2019 Jun;80:128-136. doi: 10.1016/j.jes.2018.12.003. Epub 2018 Dec 17.
The changes of protein secondary structures in the extracellular polymeric substances (EPS) extracted from activated sludge by four different methods were studied by analyzing the amide I region (1700-1600 cm) of the Fourier transform infrared spectra and model protein test. The results showed the molecular weight distribution of organic matter extracted by centrifugation, heating and cation exchange resin (CER) was similar, while the EPS extracted by centrifugation (Control) and CER had similar fluorescent organic matter. The protein secondary structures of extracted EPS by the four methods were different. The similarities of protein secondary structures between the EPS extracted by CER with the Control were the highest among the four extracted EPS. Although the EPS yield extracted by formaldehyde + NaOH method were the highest, its protein secondary structures had the lowest similarity with those extracted by the Control. Additionally, the effects of centrifugation and CER extraction on the secondary structures of bovine serum albumin were also lower than that of other extraction processes. CER enables the second maximum extraction of EPS and maximum retention of the original secondary structure of proteins.
通过分析傅里叶变换红外光谱的酰胺 I 区（1700-1600cm）和模型蛋白测试，研究了四种不同方法从活性污泥中提取的胞外聚合物（EPS）中蛋白质二级结构的变化。结果表明，离心、加热和阳离子交换树脂（CER）提取的有机物的分子量分布相似，而离心提取的 EPS（对照）和 CER 具有相似的荧光有机物。四种方法提取的 EPS 的蛋白质二级结构不同。CER 提取的 EPS 与对照之间的蛋白质二级结构相似性最高。尽管甲醛+NaOH 法提取的 EPS 产量最高，但与对照相比，其蛋白质二级结构的相似性最低。此外，离心和 CER 提取对牛血清白蛋白二级结构的影响也低于其他提取过程。CER 可实现 EPS 的第二大提取和蛋白质原始二级结构的最大保留。
