Felz Simon, Al-Zuhairy Salah, Aarstad Olav Andreas, van Loosdrecht Mark C M, Lin Yue Mei
Department of Biotechnology, Delft University of Technology.
Department of Biotechnology, Norwegian Biopolymer Laboratory (NOBIPOL), Norwegian University of Science and Technology.
J Vis Exp. 2016 Sep 26(115):54534. doi: 10.3791/54534.
To evaluate and develop methodologies for the extraction of gel-forming extracellular polymeric substances (EPS), EPS from aerobic granular sludge (AGS) was extracted using six different methods (centrifugation, sonication, ethylenediaminetetraacetic acid (EDTA), formamide with sodium hydroxide (NaOH), formaldehyde with NaOH and sodium carbonate (Na2CO3) with heat and constant mixing). AGS was collected from a pilot wastewater treatment reactor. The ionic gel-forming property of the extracted EPS of the six different extraction methods was tested with calcium ions (Ca). From the six extraction methods used, only the Na2CO3 extraction could solubilize the hydrogel matrix of AGS. The alginate-like extracellular polymers (ALE) recovered with this method formed ionic gel beads with Ca. The Ca-ALE beads were stable in EDTA, formamide with NaOH and formaldehyde with NaOH, indicating that ALE are one part of the structural polymers in EPS. It is recommended to use an extraction method that combines physical and chemical treatment to solubilize AGS and extract structural EPS.
为了评估和开发提取凝胶形成性胞外聚合物（EPS）的方法，采用六种不同方法（离心、超声处理、乙二胺四乙酸（EDTA）、氢氧化钠（NaOH）与甲酰胺、NaOH与甲醛以及加热并持续搅拌的碳酸钠（Na₂CO₃））从好氧颗粒污泥（AGS）中提取EPS。AGS取自一个中试规模的废水处理反应器。用钙离子（Ca）测试了六种不同提取方法所提取的EPS的离子凝胶形成特性。在所使用的六种提取方法中，只有Na₂CO₃提取法能够溶解AGS的水凝胶基质。用该方法回收的类藻酸盐胞外聚合物（ALE）与Ca形成了离子凝胶珠。Ca-ALE珠在EDTA、NaOH与甲酰胺以及NaOH与甲醛中稳定，这表明ALE是EPS中结构聚合物的一部分。建议采用结合物理和化学处理的提取方法来溶解AGS并提取结构EPS。
