Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.
Environ Sci Technol. 2013 Oct 15;47(20):11482-9. doi: 10.1021/es403227p. Epub 2013 Sep 25.
Phosphorus-accumulating organisms are considered to be the key microorganisms in the enhanced biological phosphorus removal (EBPR) process. A large amount of phosphorus is found in the extracellular polymeric substances (EPS) matrix of these microorganisms. However, the roles of EPS in phosphorus removal have not been fully understood. In this study, the phosphorus in the EBPR sludge was fractionated and further analyzed using quantitative (31)P nuclear magnetic resonance spectroscopy. The amounts and forms of phosphorus in EPS as well as their changes in an anaerobic-aerobic process were also investigated. EPS could act as a reservoir for phosphorus in the anaerobic-aerobic process. About 5-9% of phosphorus in sludge was reserved in the EPS at the end of the aerobic phase and might further contribute to the phosphorus removal. The chain length of the intracellular long-chain polyphosphate (polyP) decreased in the anaerobic phase and then recovered under aerobic conditions. However, the polyP in the EPS had a much shorter chain length than the intracellular polyP in the whole cycle. The migration and transformation of various forms of phosphorus among microbial cells, EPS, and bulk liquid were also explored. On the basis of these results, a model with a consideration of the roles of EPS was proposed, which is beneficial to elucidate the mechanism of phosphorus removal in the EBPR system.
聚磷菌被认为是强化生物除磷（EBPR）过程中的关键微生物。这些微生物的细胞外聚合物（EPS）基质中存在大量的磷。然而，EPS 在除磷中的作用尚未得到充分理解。在这项研究中，使用定量（31）P 核磁共振波谱法对 EBPR 污泥中的磷进行了分级，并进一步进行了分析。还研究了 EPS 中的磷含量和形态及其在厌氧-好氧过程中的变化。EPS 可以作为厌氧-好氧过程中磷的储存库。在好氧阶段结束时，污泥中约 5-9%的磷被储存在 EPS 中，可能进一步有助于除磷。在厌氧阶段，细胞内长链多磷酸盐（polyP）的链长变短，然后在好氧条件下恢复。然而，EPS 中的 polyP 的链长比整个循环中细胞内的 polyP 短得多。还探索了各种形态的磷在微生物细胞、EPS 和主体液体之间的迁移和转化。基于这些结果，提出了一个考虑 EPS 作用的模型，这有助于阐明 EBPR 系统中除磷的机制。
