title: Roles of ionic strength and biofilm roughness on adhesion kinetics of Escherichia coli onto groundwater biofilm grown on PVC surfaces.
abstract: 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 (kd) 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 kd 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.
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. djanjar2@illinois.edu
authors.forename: Dao
authors.initials: D
authors.lastname: Janjaroen
authors.forename: Fangqiong Q
authors.initials: FQ
authors.lastname: Ling
authors.forename: Fangqiong
authors.initials: F
authors.lastname: Ling
authors.forename: Guillermo
authors.initials: G
authors.lastname: Monroy
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derlon
authors.forename: Eberhard
authors.initials: E
authors.lastname: Morgenroth
authors.forename: Eberhard
authors.initials: E
authors.lastname: Mogenroth
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boppart
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.forename: Thanh H
authors.initials: TH
authors.lastname: Nguyen
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects*; D044822:Biodiversity; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D016000:Cluster Analysis; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000166:cytology* / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D060587:Groundwater / Q000737:chemistry; D007700:Kinetics; D008031:Lignin / Q000494:pharmacology; D009994:Osmolar Concentration; D012150:Polymorphism, Restriction Fragment Length; D011143:Polyvinyl Chloride / Q000494:pharmacology*; D013816:Thermodynamics; D041623:Tomography, Optical Coherence
chemical_list: D011143:Polyvinyl Chloride; D008031:Lignin