不同Cu(Ⅱ)胁迫/诱导下P. aeruginosa EPS组分变化及其吸附特性
- The changes of EPS components and adsorption characteristics of P. aeruginosa under different Cu(Ⅱ) stress/induction
- 摘要：本研究以3种不同浓度Cu(Ⅱ)化合物(Cu(NO3)2、CuSO4和CuCl2)胁迫/诱导Pseudomonas aeruginosa（P. aeruginosa），探究了胁迫/诱导前后EPS组分变化以及对Cu(Ⅱ)的吸附性能的变化。结果表明，当Cu(Ⅱ)胁迫浓度为30 mg/L时胁迫效果最好，Cu(NO3)2、CuSO4和CuCl2胁迫下EPS产量分别为333.23 mg/g VSS、280.82 mg/g VSS和181.26 mg/g VSS。同时，Cu(NO3)2-EPS对于Cu(Ⅱ)的吸附效果最好，为346.50 mg/g EPS，较胁迫前提高了86.79%。Langmuir等温模型可以很好地拟合EPS对Cu(Ⅱ)的吸附，理论最大吸附量达到2012.76 mg/g，且吸附过程符合二级动力学规律。3D-EEM和UV-Vis分析结果表明，EPS中蛋白质如类色氨酸、芳香蛋白类物质含量较胁迫前明显增加；FTIR分析表明，胁迫后C=O、C-N、C-O-C等官能团大量增加；XPS分析表明，Cu(NO3)2胁迫/诱导后，EPS中C-N、C=O等官能团增加。本研究在生物处理重金属废水的应用方面具有巨大潜力。
- Abstract：This study investigated the changes in extracellular polymeric substances (EPS) composition and its adsorption performance of Cu(Ⅱ) before and after the stress/induction of Pseudomonas aeruginosa (P. aeruginosa) with three different concentrations of Cu(Ⅱ) compounds (Cu(NO3)2, CuSO4, and CuCl2). The results showed that the optimal stress concentration was 30 mg/L, under which the EPS yields were 333.23 mg/g VSS, 280.82 mg/g VSS, and 181.26 mg/g VSS for Cu(NO?)?, CuSO?, and CuCl?, respectively. Meanwhile, Cu(NO3)2-EPS exhibited the best adsorption performance for Cu(Ⅱ), reaching 346.50 mg/g EPS, and 86.79% increases compared to before stress. The Langmuir isothermal model well fitted the adsorption of Cu(II) by EPS, with a theoretical maximum adsorption capacity of 2012.76 mg/g, and the adsorption process followed pseudo-second-order kinetics. 3D-EEM and UV-Vis analyses revealed that the content of proteins-like substances, such as tryptophan-like, aromatic protein in EPS significantly increased after stress; FTIR analysis identified a substantial increase in functional groups like C=O, C-N, C-O-C post- stress; XPS analysis further confirmed the functional groups such as C-N and C=O increased in EPS after Cu(NO3)2 stress/induction. This study demonstrates great potential for the application of biological treatment in heavy metal wastewater remediation.
