Reciprocal interaction between microbial evolution and community structure in soil

Evolutionary change can occur over comparable time scales to changes in community composition, hence rapid evolution can play a key role in community ecology and vice versa. However, we have little understanding of the significance of, or mechanisms underlying, this interaction in nature. Here, we will identify how and why the presence versus absence of a range of natural soil microbial communities affects the molecular and phenotypic evolution of a focal species of bacteria adapting to a novel environment (elevated temperature), and in turn how and why evolution of the focal species affects community composition.

The proposed work will provide an unambiguous demonstration of reciprocal interactions between microevolution and community structure within a natural community. Moreover, it will identify when and how this feedback is likely to be important. This will be the first example of such feedback in a natural environment for any organisms, hence the work will primarily be of academic benefit. We have identified three additional beneficiaries: 1) Biotechnology industry; 2) Clinicians; 3) the general public. The benefits to these groups, and how we will implement the benefits, are outlined below.

1. Biotechnology industry
Microbial communities are used in a range of applied contexts, including the production of biofuels, polymers and the remediation of pollutants. Evolution is rarely considered in these applied contexts. If feedback between microevolution and community structure is important, it will have important implications for how communities are initially designed and how often they are replaced or augmented. One context in which we can apply these ideas is in the production of biomethane. We are in discussion with New Generation Biogas (http://www.ngbiogas.com), a South-West based Biogas company, about pre-adapting biogas communities to the specific contexts in which they will be used, with the aim of greatly reducing the lag time for generating biogas in industrial reactors. The results of the current proposal will determine how this will be implemented.

2. Clinicians
Recent studies suggest that that both microevolution and community structure are important for progression of disease caused by opportunistic bacterial pathogens, notably in the context of Cystic Fibroses patients. If there is a causal link between microevolution and community structure, this opens the ways forward for probiotic manipulation in patients who frequently do not respond well to antibiotics. Our key clinical collaborator, Christian van Delden (University Hospital, Geneva), works closely with lung transplant patients, and is considering the use of probiotics to limit colonization, adaptation and virulence of opportunistic pathogens, notably Pseudomonas aeruginosa. Our results, specifically, if community diversity constrains Pseudomonas adaptation (Objective 1), will help guide this decision.

3. Public
The typical public perception of evolution is very much at the macro-scale: for example, that we share a common ancestor with chimpanzees. While there is awareness of microevolution, most obviously in the context of human disease (e.g. antibiotic resistance, influenza immune escape, etc), there are few popular and general examples of microevolution. The concept of evolution occurring on similar time scales to community change will emphasise evolution as a force that affects everyone's life. As we have done on a number of past occasions, we will promote the work through the popular science magazines (e.g. the Scientist, New Scientist) and the normal media. In order to maximise the impact, we will work with a dedicated Research Development Manager (RDM) based in the Research and Knowledge Transfer Office. The dedicated RDM will draw on University wide resources including those available within RKT Office (50 + staff) but also the Press Office, the International Office and the Development and Alumni Relations Office to ensure that results of this project are disseminated in a timely and efficient manner. The project team will also organise a series of public lectures in schools and colleges in Cornwall, as they have successfully done for other members of the Centre for Ecology and Conservation, and we will present the work at the University in Cornwall's annual public engagement day, "Science in the Square" (http://www.exeter.ac.uk/cornwall/scienceinthesquare/).