This research was supported by NSF DEB 0515832 and 0919015 and via the Indiana METACyt Initiative of Indiana University, funded in part through a major grant from the Lilly Endowment, Inc. to C. M. L, and F. B. H. H. was supported by a Fulbright fellowship from United States-Israel Educational Foundation and BIKURA fellowship from the Israel Science Foundation.
Bacteriocin-mediated interactions within and between coexisting species
Article first published online: 1 SEP 2012
© 2012 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Ecology and Evolution
Volume 2, Issue 10, pages 2521–2526, October 2012
How to Cite
Ecology and Evolution 2012; 2(10): 2516–2521
- Issue published online: 11 OCT 2012
- Article first published online: 1 SEP 2012
- Manuscript Accepted: 22 JUL 2012
- Manuscript Revised: 15 JUL 2012
- Manuscript Received: 26 JUN 2012
- National Science Foundation. Grant Numbers: 0515832, 0919015
- Lilly Endowment, Inc.
- United States-Israel Educational Foundation
- Israel Science Foundation
- entomopathogenic bacteria;
- interspecific interactions;
- intraspecific interactions;
- recognition mechanisms;
- Xenorhabdus bacteria
Bacteriocins are bacteriocidal toxins released by almost all bacteria. They are thought to have a narrow range of killing, but as bacteriocin-mediated interactions have been rarely studied at biologically relevant scales, whether this narrow range of action falls mostly within or mostly between coexisting species in natural communities is an open question with important ecological and evolutionary implications. In a previous study, we systematically sampled Xenorhabdus bacteria along a hillside and found evidence for genotypic variability and bacteriocin-mediated interactions within Xenorhabdus bovienii and X. koppenhoeferi colonies that were collected only a few meters apart. In contrast, colonies that were isolated from the same soil sample were always genetically similar and showed no inhibitions. Here, we conducted pairwise growth-inhibition assays within and between seven X. bovienii and five X. koppenhoeferi colonies that were isolated from different soil samples; all seven X. bovienii colonies and at least three of the X. koppenhoeferi have been distinguished as distinct genotypes based on coarse-grain genomic markers. We found signatures for both conspecific and heterospecific bacteriocin inhibitions in this natural community of Xenorhabdus bacteria, but intraspecific inhibitions were significantly more common than interspecific inhibitions. These results suggest that bacteriocins have a major role in intraspecific competition in nature, but also suggest that bacterocins are important in mediating interspecific interactions among coexisting species in natural communities.