The emergence and global spread of antimicrobial resistance (AMR) is a significant problem threatening human, plant, and animal health. Central to the problem of AMR are Gram-negative bacteria, which exhibit intrinsic resistance to many antibiotics due to their impermeable outer membrane (OM). A promising new avenue for antibiotic development focuses on lectin-like bacteriocins (Llps), bactericidal proteins naturally secreted by Gram-negative bacteria to eliminate their competitors. Llps have been shown to disrupt OM protein assembly, specifically binding and disrupting the BAM complex. The essentiality and surface-exposed nature of BamA have made it an attractive target for the development of novel antibiotics. Utilising Pseudomonas aeruginosa (lab strain PAO1) susceptible to the Llp pyocin L1 as a model organism. I aim to uncover the molecular mechanisms underlying Llp-mediated killing. To achieve this, we will combine proteomic and lipidomic analyses to assess the impact of Llp treatment on cellular homeostasis and to identify the cell envelope stress responses triggered by disrupted OM protein assembly. Preliminary findings have revealed potential mechanisms of resistance, which I am now investigating further to understand how these bacteria evade Llp-mediated killing. By understanding how these antibiotics affect bacterial structure and function, this work will provide insight into resistance mechanisms and inform new strategies to combat drug-resistant Gram-negative infections.