Interspecific social interactions shape public goods production in natural microbial communities

Thursday 7 November 2019, 1.00PM

Speaker(s): Elze Hesse, University of Exeter

Cooperation abounds in nature across different levels of biological organization. Explaining its mere existence remains one of the greatest challenges in evolutionary biology. Why should organisms help others at great individual cost? Microbes are ideal systems for studying cooperation given their amenability in terms of developing and testing general theory. Cooperation between microbes is often mediated by public goods – costly extracellular compounds that benefit entire groups. Public goods cooperation is typically studied in the context of within-species interactions, yet many public goods also benefit other community members. Our understanding of cooperative behaviours with community benefits is poor. Such behaviours are surprisingly common, and include detoxification of metal-polluted environments via the ubiquitous production of metal-chelating siderophores. Here I use experimental evolution combined with fitness assays to determine how exploitation of public goods by the wider microbial community shapes sidoerophore production. By simultaneously studying whole microbial communities and an embedded focal species, I show that interspecific exploitation results in both ecological selection against microbial taxa that produce relatively large amounts of siderophores, and evolution of reduced siderophore production within taxa over similar time scales. These findings demonstrate the crucial role of interspecific interactions in shaping microbial social behaviours. This is of particular importance as microbial cooperation has far-reaching consequences for ecosystem functioning, food security and human health.

Location: Dianna Bowles Lecture Theatre B/K/018