title: Paenibacillus dendritiformis bacterial colony growth depends on surfactant but not on bacterial motion.
abstract: Most research on growing bacterial colonies on agar plates has concerned the effect of genetic or morphotype variation. Some studies have indicated that there is a correlation between microscopic bacterial motion and macroscopic colonial expansion, especially for swarming strains, but no measurements have been obtained for a single strain to relate the microscopic scale to the macroscopic scale. We examined here a single strain (Paenibacillus dendritiformis type T; tip splitting) to determine both the macroscopic growth of colonies and the microscopic bacterial motion within the colonies. Our multiscale measurements for a variety of growth conditions revealed that motion on the microscopic scale and colonial growth are largely independent. Instead, the growth of the colony is strongly affected by the availability of a surfactant that reduces surface tension.
authors.affiliation: Center for Nonlinear Dynamics and Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA. beerav@gmail.com
authors.forename: Avraham
authors.initials: A
authors.lastname: Be'er
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Smith
authors.forename: H P
authors.initials: HP
authors.lastname: Zhang
authors.forename: E-L
authors.initials: EL
authors.lastname: Florin
authors.forename: Shelley M
authors.initials: SM
authors.lastname: Payne
authors.forename: Harry L
authors.initials: HL
authors.lastname: Swinney
mesh_terms: D000362:Agar; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D003470:Culture Media; D016937:Gram-Positive Endospore-Forming Rods / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology*; D008858:Microscopy, Phase-Contrast; D009068:Movement / Q000187:drug effects; D013501:Surface-Active Agents / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D013501:Surface-Active Agents; D000362:Agar