Background: Tradeoffs among competing traits are believed to be crucial to the maintenance of diversity in complex communities. The production of antibiotics to inhibit competitors and resistance to antibiotic inhibition are two traits hypothesized to be critical to microbial fitness in natural habitats, yet data on costs or tradeoffs associated with these traits are limited. In this work we characterized tradeoffs between antibiotic inhibition or resistance capacities and growth efficiencies or niche widths for a broad collection of Streptomyces from soil. Results: Streptomyces isolates tended to have either very little or very high inhibitory capacity. In contrast, Streptomyces isolates were most commonly resistant to antibiotic inhibition by an intermediate number of other isolates. Streptomyces with either very high antibiotic inhibitory or resistance capacities had less efficient growth and utilized a smaller number of resources for growth (smaller niche width) than those with low inhibition or resistance capacities, suggesting tradeoffs between antibiotic inhibitory or resistance and resource use phenotypes. Conclusions: This work suggests that life-history tradeoffs may be crucial to the maintenance of the vast diversity of antibiotic inhibitory and resistance phenotypes found among Streptomyces in natural communities.
Bibliographical noteFunding Information:
We gratefully acknowledge Anita Baines, Jen Flor, Dale Johnson, Erica Marti, and Kun Xiao for careful sampling, isolation, and phenotypic analysis of Streptomyces strains used in this work. We thank Brett Arenz, Eric Lind, Christine Salomon, and anonymous reviewers for critical and helpful feedback in preparing this manuscript. This project was supported by Agriculture and Food Research Initiative Competitive Grant Numbers 2011-67019-30200 and 2011-67019-30330 from the USDA National Institute of Food and Agriculture. Research funding was also provided by the USDA CSREES Microbial Observatories program (Grant 2006-04464), the NSF Microbial Observatories Program (Grant 9977907), the NSF Long-Term Ecological Research Program (DEB-0080382), and the Minnesota Agricultural Experiment Station.
© 2015 Schlatter and Kinkel.