Protein corona between nanoparticles and bacterial proteins in activated sludge: Characterization and effect on nanoparticle aggregation

• Published in: Bioresource technology 2018-02, Vol.250, p.10-16
• Main Authors: Zhang, Peng, Xu, Xiao-Yan, Chen, You-Peng, Xiao, Meng-Qian, Feng, Bo, Tian, Kai-Xun, Chen, Yue-Hui, Dai, You-Zhi
• Format: Article
• Language: English
• Subjects: activated sludge; adsorption; Aggregation; Bacterial Proteins; flocculation; Nanoparticles; Protein Corona; Proteins with high affinity to nanoparticles; proteomics; Sewage; Shotgun proteomics; Zinc Oxide
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.11.008

[Display omitted] •30 and 9 proteins absorbed on TNPs and ZNPs were identified, respectively.•Activated sludge had a higher affinity to TNPs than to ZNPs.•The proteins promoted to ZNPs aggregation through dissolved Zn ion-bridging.•The increasing protein enhanced the TNPs aggregation by macromolecule bridging. In this work, the protein coronas of activated sludge proteins on TiO2 nanoparticles (TNPs) and ZnO nanoparticles (ZNPs) were characterized. The proteins with high affinity to TNPs and ZNPs were identified by shotgun proteomics, and their effects of on the distributions of TNPs and ZNPs in activated sludge were concluded. In addition, the effects of protein coronas on the aggregations of TNPs and ZNPs were evaluated. Thirty and nine proteins with high affinities to TNPs and ZNPs were identified, respectively. The proteomics and adsorption isotherms demonstrated that activated sludge had a higher affinity to TNPs than to ZNPs. The aggregation percentages of ZNPs at 35, 53, and 106 mg/L of proteins were 13%, 14%, and 18%, respectively, whereas those of TNPs were 21%, 30%, 41%, respectively. The proteins contributed to ZNPs aggregation by dissolved Zn ion-bridging, whereas the increasing protein concentrations enhanced the TNPs aggregation through macromolecule bridging flocculation.