Poster Presentation Royal Australian Chemical Institute National Congress 2026

Polar sulphur accumulation as indicator for bacterial membrane stress (#523)

Simone Ries 1 , Kai Chen 1 , Cameron Evans 2 , Jungmi Park 3 , Rebecca Wolters 1 , Ewen McCabe 1 , Mana Runnion 1 , Natan Pavlos 1 , Aleksandra Debowski 1 , Fiona Moggach 1 , Mitali Sarkar-Tyson 1 , Jessica Kretzmann 1 , Andrew Barker 4 , Nicolas Taylor 1 , Marck Norret 1 , Vincent Rotello 3 , Haibo Jiang 5 , Georg Fritz 1 , Iyer Swaminathan 1
  1. UWA, Crawley, WA, Australia
  2. School of Pharmacy and Pharmacology, University of Tasmania, Sandy Bay, Tasmania, Australia
  3. Departmant of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts, USA
  4. Lixa Life Sciences, Nedlands, WA, Australia
  5. Department of Chemistry, University of Hong Kong, Pok Fu Lam, Hong Kong, China

Bacterial cell poles are distinctive membrane domains characterised by negative curvature and high cardiolipin content, serving as sites of intense metabolic activity. Membrane disruptors, a class of antimicrobials, can be structurally modified to interact with this domain, permitting the exploration of the subsequent metabolic shift. Here we show the redistribution of sulphur to the bacterial poles as consequence of membrane perturbation; a phenomenon we term polar sulphur enrichment. Using correlative ion probe imaging, we captured polar sulphur enrichment in both Gram-positive and Gram-negative bacteria, with increasing polar to lateral signal ratios following treatment. The ability of discrete amphiphilic dendron architectures to rapidly accumulate at the poles deemed to initiate polar sulphur enrichment with slower structural variants lacking this effect. The successive metabolic profiling revealed depletion of purine nucleotides and collapse of central energy cycle surpassing adaptive stress responses. We propose polar sulphur enrichment as elemental signature of oxidised, aggregated proteins accumulated at bacterial cell poles through nucleoid occlusion following membrane damage. These findings establish bacterial poles as targetable domains, identifiable by polar sulphur enrichment marking acute membrane stress.