Astrid Laimer-Digruber (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Astrid Laimer-Digruber Tanja V. Edelbacher (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Tanja V. Edelbacher Masoumeh Alinaghihossein (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Masoumeh Alinaghihossein Mia S. C. Yu Mia S. C. Yu Dapi Menglin Chiang Dapi Menglin Chiang Benedikt Kirchner Benedikt Kirchner Susanne I. Wudy Susanne I. Wudy Waltraud Tschulenk (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Waltraud Tschulenk Ingrid Walter (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Ingrid Walter Stefan Kummer (VetCore, Central Special Facilities, University of Veterinary Medicine Vienna) Stefan Kummer Christina Ludwig Christina Ludwig Jan Přibyl Jan Přibyl Michael W. Pfaffl Michael W. Pfaffl Monika Ehling-Schulz (Centre of Pathobiology, Department of Biological Sciences and Pathobiology, Departments, University of Veterinary Medicine Vienna) Monika Ehling-Schulz Springer 2026 Bacterial extracellular vesicles (EVs) are known to mediate intercellular communication, virulence, and immune modulation. Here we show that bacteria can utilise EVs also as recyclable nutrient reservoirs. Using Bacillus cereus as a model organism, we demonstrate that EVs exhibit distinct dynamics depending on growth conditions: EVs produced in complex nutrient-rich media undergo time-dependent degradation, while those produced in defined nutrient-limited conditions remain stable and accumulate. We observe similar EV degradation patterns in Staphylococcus aureus. Time-resolved multi-omics profiling reveals that EVs containing the lipid sphingomyelin undergo progressive degradation. Using pharmacological inhibition, knockout mutants, and enzymatic complementation, we show that this process is driven by secreted sphingomyelinase (SMase). This enzyme contributes to degradation of sphingomyelin-containing EVs, thereby releasing their biomolecular cargo which can be used as a nutrient source. Growth assays confirm that SMase-mediated EV degradation provides a growth advantage when nutrients become depleted, thus establishing EVs as dynamic nutrient reservoirs. PDFDocument eng 2026-10-22T08:30:33.771120020Z 2026 3118684 b application/pdf http://creativecommons.org/licenses/by/4.0/