{"paper":{"title":"Kin-ematic Exclusion in Active Matter: Modelling Mutual Inhibition in \\textit{Pseudomonas aeruginosa} Sibling Colonies","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Sibling colonies of Pseudomonas aeruginosa separate because local nutrient depletion slows growth and motility in a self-reinforcing way.","cross_cats":["physics.bio-ph"],"primary_cat":"q-bio.CB","authors_text":"Barbara Capone, Dario Buonomo, Fabio Bruni, Francesco Imperi, Marco Polin","submitted_at":"2026-05-13T15:43:56Z","abstract_excerpt":"The striking variety of macroscopic morphologies displayed by bacterial colonies depends on microscopic environmental and behavioural details in a manner that is currently not well understood. A surprising example is sibling inhibition, whereby isogenic bacterial colonies spreading in soft agar hydrogels tend to avoid each other and form sharp demarcation lines when growing nearby. Here we investigate this effect with the common pathogen \\textit{Pseudomonas aeruginosa}, by combining quantitative density measurements with a minimal biophysical model. Our results show that the phenomenon does no"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"colony separation is driven by localised nutrient depletion through a dynamic feedback between growth and motility","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The experiments have fully ruled out gel compression, lethal inhibition and quorum sensing as contributors, so the nutrient-motility mechanism is the dominant cause.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Sibling inhibition between isogenic P. aeruginosa colonies arises from nutrient depletion feedback on growth and motility rather than gel compression, lethality, or quorum sensing.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Sibling colonies of Pseudomonas aeruginosa separate because local nutrient depletion slows growth and motility in a self-reinforcing way.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"3197775c9ae2aea75d34eadde5a4a62a5d8aff6bced21c4cf1d760feb311130d"},"source":{"id":"2605.13927","kind":"arxiv","version":1},"verdict":{"id":"4610f3e4-806f-49e7-a6ed-dbf2f8318c19","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T02:36:27.787520Z","strongest_claim":"colony separation is driven by localised nutrient depletion through a dynamic feedback between growth and motility","one_line_summary":"Sibling inhibition between isogenic P. aeruginosa colonies arises from nutrient depletion feedback on growth and motility rather than gel compression, lethality, or quorum sensing.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The experiments have fully ruled out gel compression, lethal inhibition and quorum sensing as contributors, so the nutrient-motility mechanism is the dominant cause.","pith_extraction_headline":"Sibling colonies of Pseudomonas aeruginosa separate because local nutrient depletion slows growth and motility in a self-reinforcing way."},"references":{"count":60,"sample":[{"doi":"","year":2018,"title":"Y. M. Bar-On, R. Phillips, and R. Milo, Proceedings of the National Academy of Sciences115, 6506 (2018)","work_id":"3e853714-4282-4aca-ba22-934c8f9c8456","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2007,"title":"F. Azam and F. Malfatti, Nature reviews. Microbiology 5, 782 (2007)","work_id":"a006d5f0-568b-49b4-b48a-13f77828428a","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2012,"title":"Stocker, Science338, 628 (2012)","work_id":"7d2fd012-24c0-4f1a-a220-aab74d936afd","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2021,"title":"T. Bhattacharjee, D. B. Amchin, J. A. Ott, F. Kratz, and S. S. Datta, Biophysical Journal120, 3483 (2021)","work_id":"cff2c44f-d02c-4ac7-8dbc-c5b6bf61552b","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1989,"title":"A. Wolfe and H. Berg, Proceedings of the National Academy of Sciences of the United States of America 86, 6973 (1989)","work_id":"bcb6a050-6d96-458b-ac8e-5fec908842de","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":60,"snapshot_sha256":"ab0aaacb5fc7f0681634968da733156391237abffe50ad8eace52212b3a4e66d","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}