Quantifying the Adhesion and Interaction Forces Between Pseudomonas aeruginosa and Natural Organic Matter

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• 作者：Laila I. Abu-Lail ; Yatao Liu ; Arzu Atabek ; Terri A. Camesano
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：December 1, 2007
• 年：2007
• 卷：41
• 期：23
• 页码：8031 - 8037
• 全文大小：333K
• 年卷期：v.41,no.23(December 1, 2007)
• ISSN：1520-5851

文摘

Atomic force microscopy (AFM) was used to characterize interactions between natural organic matter (NOM), and glass or bacteria. Poly(methacrylic acid) (PMA), soil humic Acid (SHA), and Suwannee River humic Acid (SRHA), were adsorbed to silica AFM probes. Adhesion forces (F_adh) for the interaction of organic-probes and glass slides correlated with organic molecular weight (MW), but not with radius of the organic aggregate (R), charge density (Q), or zeta potential (ζ). Two Pseudomonas aeruginosa strains with different lipopolysaccharides (LPS) were chosen: PAO1 (A⁺B⁺), whose LPS have common antigen (A-band) + O-antigen (B-band); and mutant AK1401 (A⁺B⁻). F_adh between bacteria and organics correlated with organic MW, R, and Q, but not ζ. PAO1 had lower F_adh with silica than NOM, which was attributed to negative charges from the B-band polymers causing electrostatic repulsion. AK1401 adhered stronger to silica than to the organics, perhaps because the absence of the B-band exposed underlying positively charged proteins. DLVO calculations could not explain the differences in the two bacteria or predict qualitative or quantitative trends in interaction forces in these systems. Molecular-level information from AFM studies can bring us closer to understanding the complex nature of bacterial–NOM interactions.