Devika Ramesh, Emanuele Fara, Franziska Oschmann, Giovanni Stefano Ugolini, Roman Stocker, Simon van Vliet, Martin Ackermann, Olga T. Schubert
populations. We found that without external amino acids, auxotroph growth is strongly constrained by low amino acid leakage from wildtype neighbors, and further reduced when they form local clusters that drain this limited amino acid pool. A growth advantage was only observed when amino acids were added or when leakage from wildtypes exceeded a threshold. Together, our results reveal insights into determinants of mutant invasion fitness and the trade-offs between reducing metabolic costs and maintaining metabolic autonomy.