MICROCOSMS · Exploring microbial community stability across mutational spectra
Horizon Europe — Marie Skłodowska-Curie Actions
- Duration
- 2023-07-01 → 2025-06-30
- EU contribution
- €181,153
- Participants
- 2
- Scheme
- HORIZON-TMA-MSCA-PF-EF
Lines connect the coordinator with its partners.
Results in brief
Exploring microbial community stability across mutational spectra
Mutualistic interactions – where both species benefit – lie at the core of many human-relevant microbial communities, such as polymicrobial infections, the human-, plant-, and animal-associated beneficial microbiomes, and synthetic microbial communities in biotechnology. However, previous work has suggested that mutualisms can break down when under particularly strong selective pressures, such as strong antibiotics. Therefore the ability to predict and prevent mutualism breakdown is an important goal for many fundamental and applied fields of biology. To help bridge this gap, our work combines evolutionary biology and ecology to elucidate the role of mutation rate and bias on the stability of mutualisms under stress. In brief, I conducted evolution experiments in obligate mutualistic pairs of non-pathogenic E. coli under strong antibiotic selection. These communities contained mutator strains, which are microbial strains that have highly elevated mutation rates and biases towards specific classes of mutations. We were able to uncover adaptive pathways only accessible to communities containing multiple mutators, and adaptive pathways in other communities only accessible by specific types of mutator strains. This helps provide us insights into the role of mutation biases in the adaptation to both abiotic and biotic factors in microbial communities. Our results advance our understanding of the predictability of mutualism breakdown in pairwise mutualistic communities, ultimately contributing to the prevention or elicitation of microbial community collapse in both natural and synthetic microbial ecosystems.
Data: CORDIS, © European Union
Project objective
Interactions in which all partners benefit, known as mutualisms, underpin many vital ecosystem functions all across nature. Recent work by myself and others has shown that mutualisms can readily break down via a few independence-enabling mutations, especially under environmental stress. Understanding the mechanisms that ensure mutualism stability is of increased importance for environmental, health, and societal problems. An unexplored question is the impact that large variations in mutational rates and spectra can have on in this process. Indeed, mutator strains, variants with highly elevated and biased mutation rates, readily take over microbial populations when there is ample adaptive opportunity, such as under environmental stress. These dramatic changes in spontaneous mutagenesis can have opposing effects on mutualism stability. On the one hand, they can lead to adaptive mutations appearing more rapidly, promoting partners survival and hence stabilising mutualisms. On the other hand, they may accelerate the acquisition of independence-enabling mutations, hence destabilising mutualism. With MICROCOSMS, I will address this open question by combining computer simulation with experimental evolution and genomics. I will experimentally evolve pairwise auxotrophic E. coli communities, genetically engineered to contain mutator variants that alter the mutational spectrum available. Pairwise communities will be assessed for mutualism stability when subject to both adaptive evolution, under strong antibiotic pressure, and non-adaptive evolution, where populations are subject to severe bottlenecking. These will be matched to simulations predicting the outcome of adaptive and non-adaptive evolution. By producing key insights into the stability of mutualisms under environmental stress, MICROCOSMS will form a knowledge base that will aide in protecting environmental and human-based ecosystems against disruptions.
Original text from CORDIS.
Participants
Links
- View on CORDIS
- DOI: 10.3030/101109457
- https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e5066f5eea&appId=PPGMS
- https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e51f5f4968&appId=PPGMS
Data: CORDIS, © European Union