title: E. coliSurface Properties Differ between Stream Water and Sediment Environments.
abstract: The importance ofE. colias an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences inE. colicell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics ofE. coliobtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically differentE. colistrains (44 strains isolated from sediments and 33 strains isolated from water) under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10 mM and 22°C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity, and extracellular polymeric substance (EPS) composition. Our results indicate that stream sedimentE. colihad significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream waterE. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sedimentE. colibut not for stream waterE. coli. Additionally,E. colisurviving in the same habitat tended to have significantly larger (GTG)5genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such asE. coli.
authors.affiliation: Department of Agricultural and Biosystems Engineering, Iowa State University, Ames IA, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Microbiology, Iowa State University, Ames IA, USA.
authors.forename: Chunyu
authors.initials: C
authors.lastname: Liao
authors.affiliation: Department of Agronomy, Iowa State University, Ames IA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Thompson
authors.affiliation: Department of Agricultural and Biosystems Engineering, Iowa State University, Ames IA, USA.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Soupir
authors.affiliation: Department of Microbiology, Iowa State University, AmesIA, USA; Department of Chemical and Biological Engineering, Iowa State University, AmesIA, USA.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Jarboe
authors.affiliation: Department of Statistics, Iowa State University, Ames IA, USA.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Dixon
keywords: E. coli; particle; stream; surface property; water quality