Local adaptation of a bacterium is as important as its presence in structuring a natural microbial community

This is the final version of the article. Available from Springer Nature via the DOI in this record.Local adaptation of a species can affect community composition, yet the importance of local adaptation compared with species presence per se is unknown. Here we determine how a compost bacterial community exposed to elevated temperature changes over 2 months as a result of the presence of a focal bacterium, Pseudomonas fluorescens SBW25, that had been pre-adapted or not to the compost for 48 days. The effect of local adaptation on community composition is as great as the effect of species presence per se, with these results robust to the presence of an additional strong selection pressure: an SBW25-specific virus. These findings suggest that evolution occurring over ecological time scales can be a key driver of the structure of natural microbial communities, particularly in situations where some species have an evolutionary head start following large perturbations, such as exposure to antibiotics or crop planting and harvesting.The work was funded by BBSRC, AXA Research fund and NERC. P.G. was supported by a Marie Curie Intra-European Fellowship within the European Commission 7th Framework Program (PIEF-GA-2010-272945), and acknowledges the Spanish MINECO support (AGL2014-59556-R). A.B. was supported by the Royal Society (UK). L.D.M. acknowledges the KU Leuven Research Fund support PF/2010/07