Inhibitory interactions promote frequent bistability among competing bacteria.
It is largely unknown how the process of microbial community assembly is affected by the order of species arrival, initial species abundances and interactions between species. A minimal way of capturing competitive abilities in a frequency-dependent manner is with an invasibility network specifying whether a species at low abundance can increase in frequency in an environment dominated by another species. Here, using a panel of prolific small-molecule producers and a habitat with feast-and-famine cycles, we show that the most abundant strain can often exclude other strains--resulting in bistability between pairs of strains. Instead of a single winner, the empirically determined invasibility network is ruled by multiple strains that cannot invade each other, and does not contain loops of cyclic dominance. Antibiotic inhibition contributes to bistability by helping producers resist invasions while at high abundance and by reducing producers' ability to invade when at low abundance.
Department of Bacteriology, Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N. Orchard Street, Madison, Wisconsin 53715, USA.
Erik S
ES
Wright
Department of Bacteriology, Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N. Orchard Street, Madison, Wisconsin 53715, USA.
Kalin H
KH
Vetsigian
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D058491:Bacterial Load / Q000187:drug effects; D004269:DNA, Bacterial / Q000235:genetics*; D017753:Ecosystem; D059013:Microbial Consortia / Q000187:drug effects / Q000235:genetics*; D056265:Microbial Interactions / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013302:Streptomyces / Q000187:drug effects / Q000235:genetics*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial