Zhu Liang, Yu Haitian, Liu Yimei, Qi Hanying, Xu Xiangyang
Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China E-mail:
Hangzhou Environmental Monitoring Center, Hangzhou, 310007, China.
Water Sci Technol. 2015;71(7):1106-12. doi: 10.2166/wst.2015.043.
The extracellular polymeric substances (EPS) are important macromolecular components in microbial aggregates. The three EPS extraction methods - ultrasound + cation exchange resins (CER) + sulfide, ultrasound + formamide + NaOH, and ultrasound + heat - were investigated in the study, and the component differences of extracted EPS from the loose flocs and dense aerobic granules were compared using chemical analysis and three-dimensional excitation-emission matrix (3D-EEM). Results showed that the contents of EPS were extracted effectively by ultrasound + formamide + NaOH and ultrasound + heat methods, and the ultrasound + CER + sulfide method did not extract the polysaccharides (PS) or protein (PN) contents from the sludge samples. The 3D-EEM analysis indicated that the nature of peak B/D, peak C/E/F, and peak A/G were attributed to PN-like, humic acid-like and fulvic acid-like fluorophores. All fluorophores can be detected from the EPS extracted through the ultrasound + heat method. Hopefully this will provide more information about the EPS interaction mechanism of microbial aggregates.
胞外聚合物（EPS）是微生物聚集体中的重要大分子成分。本研究考察了三种EPS提取方法——超声+阳离子交换树脂（CER）+硫化物、超声+甲酰胺+氢氧化钠和超声+加热，并采用化学分析和三维激发-发射矩阵（3D-EEM）比较了从松散絮体和密实好氧颗粒中提取的EPS的成分差异。结果表明，超声+甲酰胺+氢氧化钠法和超声+加热法能有效提取EPS含量，而超声+CER+硫化物法未从污泥样品中提取出多糖（PS）或蛋白质（PN）含量。3D-EEM分析表明，峰B/D、峰C/E/F和峰A/G的性质分别归因于类PN、类腐殖酸和类富里酸荧光团。通过超声+加热法提取的EPS中可检测到所有荧光团。希望这将为微生物聚集体的EPS相互作用机制提供更多信息。
