Roles of ionic strength and biofilm roughness on adhesion kinetics of Escherichia coli onto groundwater biofilm grown on PVC surfaces

WATER RESEARCH

卷:47

Article

Janjaroen, Dao¹  Ling, Fangqiong¹  Monroy, Guillermo²  Derlon, Nicolas⁴  Mogenroth, Eberhard^4,5  Boppart, Stephen A.^2,3  Liu, Wen-Tso¹  Nguyen, Thanh H.¹ 

[1] Univ Illinois, Dept Civil & Environm Engn, Urbana, IL 61801 USA

[2] Univ Illinois, Dept Bioengn, Urbana, IL 61801 USA

[3] Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA

[4] Eawag Swiss Fed Inst Aquat Sci & Technol, CH-8600 Dubendorf, Switzerland

[5] ETH, Inst Environm Engn, CH-8093 Zurich, Switzerland

关键词: Drinking water distribution system;    Biofilm;    Pathogens;   

DOI  :  10.1016/j.watres.2013.02.032

来源: Elsevier

【 摘 要 】

Mechanisms of Escherichia coli attachment on biofilms grown on PVC coupons were investigated. Biofilms were grown in CDC reactors using groundwater as feed solution over a period up to 27 weeks. Biofilm physical structure was characterized at the micro- and meso-scales using Scanning Electron Microscopy (SEM) and Optical Coherence Tomography (OCT), respectively. Microbial community diversity was analyzed with Terminal Restricted Fragment Length Polymorphism (T-RFLP). Both physical structure and microbial community diversity of the biofilms were shown to be changing from 2 weeks to 14 weeks, and became relatively stable after 16 weeks. A parallel plate flow chamber coupled with an inverted fluorescent microscope was also used to monitor the attachment of fluorescent microspheres and E. coli on clean PVC surfaces and biofilms grown on PVC surfaces for different ages. Two mechanisms of E. coli attachment were identified. The adhesion rate coefficients (k(d)) of E. coli on nascent PVC surfaces and 2-week biofilms increased with ionic strength. However, after biofilms grew for 8 weeks, the adhesion was found to be independent of solution chemistry. Instead, a positive correlation between k(d) and biofilm roughness as determined by OCT was obtained, indicating that the physical structure of biofilms could play an important role in facilitating the adhesion of E. coli cells. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free