Cultivation substrata differentiate the properties of river biofilm EPS and their binding of heavy metals: A spectroscopic insight
Cultivation substrata differentiate the properties of river biofilm EPS and their binding of heavy metals: A spectroscopic insight
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栽培基质区分河流生物膜 EPS 的特性及其与重金属的结合：光谱洞察
DOI：
10.1016/j.envres.2019.109052
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发表时间：
2020
影响因子：
8.3
通讯作者：
Niu Lihua
中科院分区：
文献类型：
--
作者：
Wang Longfei;Chen Wei;Song Xiaochong;Li Yi;Zhang Wenlong;Zhang Huanjun;Niu Lihua
河流生物膜是铜、镉等重金属进入河流系统后不可避免的接受者。然而，培养基质对河流生物膜胞外聚合物（EPS）特性的影响以及重金属在生物膜上的结合行为尚不清楚。结合光谱方法与化学计量学分析，我们探讨了铜（II）和镉（II）对生物膜EPS培养从两个代表性的基质在分子水平上的结合行为。化学分析表明，在聚乙烯（PE）片上培养的生物膜含有更多的非荧光蛋白组分，而来自在矿物上生长的附着生物的EPS，即，鹅卵石富含芳香组分和多糖。激发-发射矩阵结合平行因子分析表明，与塑料生物膜EPS中的荧光团相比，在外周型EPS中的荧光团与Cu（II）之间的相互作用更强。综合利用红外光谱和二维相关分析表明，在重金属结合过程中，塑料生物膜EPS中的胺类和酚类物质对金属结合的反应最快。而酰胺类和脂族组分对重金属有优先结合作用。本研究区分了培养基质对生物膜EPS特性的影响，并为河流生物膜基质中重金属排入河流系统的环境行为提供了新的见解。
River biofilms inevitably serve as recipients of heavy metals including copper (Cu) and cadmium (Cd) following their introduction in fluvial systems. Nevertheless, the effects of cultivation substrata on the characteristics of river biofilm extracellular polymeric substances (EPS) and the binding behaviors of heavy metals on biofilms remain unclear. Integrating spectroscopic methods with chemometric analyses, we explored the binding behaviors of Cu(II) and Cd(II) onto biofilm EPS cultivated from two representative substrata at the molecular level. Chemical analysis revealed that biofilm cultivated on polyethylene (PE) pieces contained more non-fluorescent protein fractions, whereas EPS from periphyton grown on mineral, i.e., cobblestones was richer in aromatic fractions and polysaccharides. Excitation-emmision matrix combined with parallel factor analysis suggested a stronger interaction between fluorophores in periphytic EPS with Cu(II) compared to fluorophores in plastic biofilm EPS. Integrated use of infrared spectroscopy and two-dimensional correlation analyses revealed that, during the heavy metal binding processes, the amines and phenolics in plastic biofilm EPS gave the fastest responses to metal binding. While the amides and the aliphatic fractions in periphytic EPS showed a preferential binding to heavy metals. This study differentiates the effects of cultivation substrata on structuring the biofilm EPS characteristics and offers new insights into the environmental behaviors of heavy metal discharge into fluvial systems in river biofilm matrix.