Department of Biological and Environmental Engineering, Hefei University, Hefei, 230601, People's Republic of China.
Anhui Key Laboratory of Sewage Purification and Eco-restoration Materials, Hefei, 230088, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Feb;25(6):5491-5500. doi: 10.1007/s11356-017-0784-6. Epub 2017 Dec 7.
Ultraviolet-visible (UV-Vis) absorbance spectra were adopted to quantify the binding of metal ions (e.g., Fe(III), Cu(II), Pb(II), and Cd(II)) on three MW fractions (> 100, 10100, and < 10 k Da) of extracellular polymeric substances (EPS) extracted from mixed cultures dominated by anaerobic ammonium-oxidizing bacteria (AnAOB). The results showed that the AnAOB EPS with different MW size ranges all had strongest binding capability of Fe(III), and the lowest binding capability of Cd(II). The complexation ability of metal ions for the EPS of AnAOB with molecular weight < 10 kDa was stronger than EPS with >100 and 10100 kDa, very likely because of the contribution of the tyrosine-, tryptophan-, and aromatic protein-like components. It was obvious that the different size fractions of EPS affect the metal binding ability. Essentially, the content of proteins, polysaccharides, TOC, and UVA distributed within various MW fractions of EPS from AnAOB were different, as well as the different fluorescent components and total functional groups.
采用紫外-可见（UV-Vis）吸收光谱法来定量研究金属离子（如 Fe(III)、Cu(II)、Pb(II) 和 Cd(II)）与从以厌氧氨氧化菌（AnAOB）为主的混合培养物中提取的细胞外聚合物（EPS）的三个 MW 级分（>100、10100 和 <10 kDa）之间的结合。结果表明，不同 MW 大小范围的 AnAOB EPS 均具有最强的 Fe(III)结合能力，而对 Cd(II)的结合能力最低。分子量 <10 kDa 的 AnAOB EPS 对金属离子的络合能力强于 100 和 10100 kDa 的 EPS，这很可能是由于酪氨酸、色氨酸和芳香族蛋白样成分的贡献。显然，EPS 的不同大小分数会影响金属的结合能力。从本质上讲，各种 MW 级分的 EPS 中的蛋白质、多糖、TOC 和 UVA 含量不同，以及不同的荧光成分和总官能团也不同。
