PS 9-100 - Impact of phage-bacteria interactions on a bacterial dynamic communities in changing environment

Monday, August 8, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Mathilde M. Besson, Département des Sciences Biologiques, Université de Montréal, Montréal, QC, Canada; Québec Centre for Biodiversity Science, Montréal, QC, Canada, Dominique Gravel, Départment de Biologie, University of Sherbrooke, Sherbrooke, QC, Canada and Timothée Poisot, Sciences Biologiques, Université de Montréal, Montréal, QC, Canada
Background/Question/Methods

Bacterial communities play a crucial role in ecosystem functioning, and their population dynamics have been shown to be influenced by interaction with bacteriophage. Yet, the embeddedness of bacteria and phages interactions in the whole network is still poorly understood. There is almost no information on how phages affect the structure of bacterial communities. In addition, in a context of climate change, few studies have explored the responses of species' interactions to local adaptation and climate change. Previous studies have demonstrated that temperature affects trophic interactions, which suggests that phage-bacteria interactions and their structure could also be impacted by temperature change. Here we seek to complete these gaps by studying the dynamic adaptation of phage-bacteria interactions under temperature changes, by (i) investigating how bacteria and phages are affected by climate change and (ii) how temperature influences the structure of phage-bacteria interactions. This will be done by  modeling dynamics of phage-bacteria interactions and experimentally exploring these interactions within Sarracenia purpurea (L.). This pitcher plant contains a wild range of phage-bacteria interactions in a
controlled and well-known environment. Moreover, it has a large geographical range. We used a probabilistic model based on influence of local adaptation and species interactions under climate change, to estimate (i) bacterial and phage fitness and their variations and (ii) the influence of temperature on the structure of phage-bacteria interactions.

Results/Conclusions

Our results indicate that fitness of bacteria is influenced both by changing temperature and local adaptation to phages predation. At different temperatures, phages have stronger effect on bacterial population dynamic due to their better resistance of temperature variation. In the same way, the optimum temperature of phages is wider than the one of bacteria. Concerning the structure of phage-bacteria interactions, we highlighted a general nested structure, even with temperature change. We concluded that, due to a greater resistance to temperature changes, phage have a strong impact on bacterial communities, with hight probability of co-evolutionary process between phage and bacteria across changing environment.