Adhesion of Shewanella oneidensis MR-1 to Goethite: A Two-Dimensional Correlation Spectroscopic Study

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• 作者：Wei Yan ; Hongbo Wang ; Chuanyong Jing
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：April 19, 2016
• 年：2016
• 卷：50
• 期：8
• 页码：4343-4349
• 全文大小：447K
• 年卷期：0
• ISSN：1520-5851

文摘

Bacterial adhesion to mineral surfaces is an important but underappreciated process. To decipher the molecular level process and mechanism, the adhesion of Shewanella oneidensis MR-1 cells to goethite was investigated using flow-cell attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy coupled with two-dimensional correlation spectroscopy (2D-COS) analysis. The FTIR results indicate that bacterial phosphate-moieties play an important role in the formation of mono- and bidentate inner-sphere complexes, whereas carboxylic groups on cell surface only have a minor contribution to its adhesion. The 2D-COS analysis in short-term (0–120 min) and long-term (2–18 h) stages reveal that the adhesion process was in the following sequence: change in H-bonds of proteins on cell surfaces > formation of monodentate inner-sphere surface complexes > formation of outer-sphere surface complexes > transformation of protein secondary structure on cell surfaces > formation of additional bridging bidentate surface complexes. In addition, the adhesion of MR-1 cells on goethite was pH dependent due to pH impacts on the cell structure and the interface charge. The in situ ATR-FTIR integrated with 2D-COS analysis highlights its great potential in exploring complex surface reactions with microbes involved. These results improve our understanding of microbe–mineral interactions at the molecular level and have significant implications for a series of biogeochemical processes.