1. Survival of the weakest in non-transitive asymmetric interactions among strains of E. coli
- Author
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Jeff Hasty, Arianna Miano, Lin Chao, Michael J. Liao, and Chloe B Nguyen
- Subjects
0301 basic medicine ,Science ,Ecology (disciplines) ,030106 microbiology ,Biodiversity ,General Physics and Astronomy ,Biology ,Models, Biological ,General Biochemistry, Genetics and Molecular Biology ,Article ,Microbial ecology ,03 medical and health sciences ,Models ,Escherichia coli ,Hierarchical organization ,2.2 Factors relating to the physical environment ,Computer Simulation ,Aetiology ,Transitive relation ,Multidisciplinary ,Microbial Viability ,Immunity ,General Chemistry ,Biological ,Bacterial synthetic biology ,genomic DNA ,030104 developmental biology ,Microbial population biology ,Evolutionary biology ,Spatial ecology ,Infection - Abstract
Hierarchical organization in ecology, whereby interactions are nested in a manner that leads to a dominant species, naturally result in the exclusion of all but the dominant competitor. Alternatively, non-hierarchical competitive dynamics, such as cyclical interactions, can sustain biodiversity. Here, we designed a simple microbial community with three strains of E. coli that cyclically interact through (i) the inhibition of protein production, (ii) the digestion of genomic DNA, and (iii) the disruption of the cell membrane. We find that intrinsic differences in these three major mechanisms of bacterial warfare lead to an unbalanced community that is dominated by the weakest strain. We also use a computational model to describe how the relative toxin strengths, initial fractional occupancies, and spatial patterns affect the maintenance of biodiversity. The engineering of active warfare between microbial species establishes a framework for exploration of the underlying principles that drive complex ecological interactions., The maintenance of ecological diversity depends on the strength and direction of competitive interactions, but these interactions are difficult to study in microbial communities. Here the authors use engineered E. coli strains to show that competitively weak strains can persist when pairwise interactions are asymmetrical.
- Published
- 2020