title: The idiosyncrasy of spatial structure in bacterial competition.
abstract: BACKGROUND
  The spatial structure of a habitat can have a strong impact on community dynamics. Different experimental approaches exist to explore the effect of spatial structure on bacterial communities. To investigate the effect of 'space', a single implementation of spatial structure is often contrasted to bacterial community dynamics in well-mixed cultures. While such comparisons are useful, it is likely that the observed dynamics will be particular to the specific experimental implementation of spatial structure. In order to address this question, we track the community dynamics of a two-strain Escherichia coli community in various spatial habitats and relate the observed dynamics to the structure of a habitat.
  
  
  RESULTS
  By tracking the community dynamics of rpoS wild-type and mutant E. coli in radially expanding colonies on solid and semi-solid agar plates, we find that the mutant strain outcompetes the wild-type on semi-solid agar plates, whereas the two strains coexist on solid agar. We compare these results to previous studies in which the same two strains were shown to coexist in habitats spatially structured by microfabrication, while the mutant outcompeted the wild-type in well-mixed batch cultures. Together, these observations show that different implementations of space may result in qualitatively different community dynamics. Furthermore, we argue that the same competitive outcome (e.g. coexistence) may arise from distinct underlying dynamics in different experimental implementations of spatial structure.
  
  
  CONCLUSIONS
  Our observations demonstrate that different experimental implementations of spatial structure may not only lead to quantitatively different communities (changes in the relative abundance of types) but can also lead to qualitatively different outcomes of long-term community dynamics (coexistence versus extinction and loss of biodiversity).
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands. f.j.h.hol@tudelft.nl.
authors.forename: Felix J H
authors.initials: FJ
authors.lastname: Hol
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands. galajda.peter@brc.mta.hu.|Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, Szeged, Hungary. galajda.peter@brc.mta.hu.
authors.forename: Peter
authors.initials: P
authors.lastname: Galajda
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands. rutger@woolthuis.nl.
authors.forename: Rutger G
authors.initials: RG
authors.lastname: Woolthuis
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands. C.Dekker@tudelft.nl.
authors.forename: Cees
authors.initials: C
authors.lastname: Dekker
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands. jkeymer@uc.cl.|Department of Ecology, Faculty of Biological Sciences, P. Catholic University of Chile, Alameda 340, Santiago, Chile. jkeymer@uc.cl.|Institute of Physics, Faculty of Physics, P. Catholic University of Chile, Ave. Vicuña Mackenna 4860, Macul, Santiago, Chile. jkeymer@uc.cl.
authors.forename: Juan E
authors.initials: JE
authors.lastname: Keymer
mesh_terms: D000362:Agar; D000898:Antibiosis / Q000502:physiology*; D061249:Batch Cell Culture Techniques; D015169:Colony Count, Microbial; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development*; D005110:Extracellular Space / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology*
chemical_list: D003470:Culture Media; D000362:Agar