Alan Pacheco

From the search for life beyond Earth, to ecosystem ecology, to the future of sustainable food. Join us at UNIL on Nov 20 for "Life in Flux:" a symposium exploring how microbial metabolism shapes ecosystems and life across scales. Info + registration: www.unil.ch/events/en/17...

career5.successfactors.euOpportunités de carrière : Doctoral Student SNSF in Quantitative Microbial Ecology and Metabolic Interactions (23002)

Our group is recruiting a PhD student! Interested in microbial interactions, metabolic ecology, and community dynamics? Join us to combine experiments, data, and quantitative thinking, within the context of soil- and plant-associated microbial communities. 📅 Apply by Oct 30 🔗 tinyurl.com/u9bvjphb

doi.orgMetabolic feedbacks drive population dynamics and can lead to oscillations among leaf bacteria - Nature CommunicationsPlant-associated bacteria engage in complex metabolic interactions. Here authors used microfluidics and computational modeling to identify molecular drivers of these interactions and disentangle their...

New here, so hoping for a grace period for posting papers a bit late! Excited to finally share our work from my time in the Vorholt Lab, co-led with Stefano Ugolini in the Stocker group at ETH and collaborators from the Segrè lab at BU and the NCCR Microbiomes. doi.org/10.1038/s41467-026-73686-w

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These distinct mechanisms produced strikingly different ecological outcomes: from stable coexistence and competitive exclusion to oscillatory dynamics. Metabolic modeling with the group of @dsegre.bsky.social allowed us to peer into the mechanisms of these states and modulate them experimentally.

Overall, our findings challenge the idea of neatly defined trophic layers in leaf microbiomes and highlight the complementary roles of carbon and vitamin exchange in shaping microbial community dynamics and coexistence. A huge thank you to all involved for the amazing collaboration!

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While we identified cases in which plant polysaccharide degraders directly enabled the growth of recipient strains, the major polysaccharide-derived monomers often played only a minor role in sustaining these interactions.

In one case, the recipient could even compete with the degrader for the primary substrate itself. Instead, vitamin exchange emerged as a critical mechanism enabling the interaction, highlighting how positive interactions can arise through very different metabolic routes.

We combined microfluidics, metabolomics, and modeling to investigate how trophic interaction dynamics can emerge among leaf-associated bacteria during plant polysaccharide degradation. What we found was more complex than we expected: