State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China.
Environ Res. 2021 Mar;194:110646. doi: 10.1016/j.envres.2020.110646. Epub 2020 Dec 22.
Anammox bacteria are widely found to grow in bioaggregates form, but the reason for their high aggregation ability remains elusive. In this study, four kinds of sludge, i.e., anammox granules, anaerobic granules, aerobic granules, and partial nitrification flocs, were studied and compared to investigate their differences in adherence properties. We directly explored the adherence properties of sludge samples before and after extracellular polymeric substances (EPS) extraction, using quartz-crystal microbalance technique with dissipation monitoring technique. Results showed that EPS indeed stimulated the adherence properties of all sludge samples. The most striking feature here is that anammox consortia had the highest adhesion rate and mass, and formed the most compact layer on the gold-coated sensor surfaces both before and after EPS extraction among the four sludge samples, indicating their inherent high adhesion ability. The composition and spectral characteristics of EPS samples were also investigated, and it reveals that the relatively high extracellular proteins/polysaccharides ratio of anammox granules (3.2 ± 0.4) rather than total EPS concentration had contributed to their high adhesion ability. The findings are helpful for understanding the adherence properties of anammox bacteria, and will serve as a guide for further researches to exploring the aggregation process of anammox bacteria.
厌氧氨氧化菌被广泛发现以生物聚集体的形式生长，但它们高聚集能力的原因仍不清楚。在这项研究中，研究了四种污泥，即厌氧氨氧化颗粒、厌氧颗粒、好氧颗粒和部分硝化絮体，以研究它们在附着特性上的差异。我们使用石英晶体微天平技术和耗散监测技术，直接探索了提取细胞外聚合物（EPS）前后污泥样品的附着特性。结果表明，EPS 确实刺激了所有污泥样品的附着特性。这里最显著的特点是，在提取 EPS 前后，厌氧氨氧化菌聚集体在金涂层传感器表面上具有最高的附着率和质量，并且形成了最紧凑的层，这表明它们具有固有的高附着能力。还研究了 EPS 样品的组成和光谱特征，结果表明，厌氧氨氧化颗粒中相对较高的细胞外蛋白质/多糖比（3.2±0.4）而不是总 EPS 浓度，导致了它们的高附着能力。这些发现有助于理解厌氧氨氧化菌的附着特性，并将为进一步研究探索厌氧氨氧化菌的聚集过程提供指导。
