Monitoring intraspecies competition in a bacterial cell population by cocultivation of fluorescently labelled strains.
Many microorganisms such as bacteria proliferate extremely fast and the populations may reach high cell densities. Small fractions of cells in a population always have accumulated mutations that are either detrimental or beneficial for the cell. If the fitness effect of a mutation provides the subpopulation with a strong selective growth advantage, the individuals of this subpopulation may rapidly outcompete and even completely eliminate their immediate fellows. Thus, small genetic changes and selection-driven accumulation of cells that have acquired beneficial mutations may lead to a complete shift of the genotype of a cell population. Here we present a procedure to monitor the rapid clonal expansion and elimination of beneficial and detrimental mutations, respectively, in a bacterial cell population over time by cocultivation of fluorescently labeled individuals of the Gram-positive model bacterium Bacillus subtilis. The method is easy to perform and very illustrative to display intraspecies competition among the individuals in a bacterial cell population.
Department of General Microbiology, Georg-August University.
Lorena
L
Stannek
Richard
R
Egelkamp
Katrin
K
Gunka
Fabian M
FM
Commichau
D001412:Bacillus subtilis / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics; D008856:Microscopy, Fluorescence / Q000379:methods
D001426:Bacterial Proteins; C485182:Cyan Fluorescent Protein; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins