Ouwehand Jesse, Brinkmann Bregje W, Peijnenburg Willie J G M, Vijver Martina G
Institute of Environmental Sciences (CML), Leiden University, PO Box 9518 Leiden 2300 RA, The Netherlands.
National Institute of Public Health and the Environment (RIVM), PO Box 1 Bilthoven, The Netherlands.
FEMS Microbiol Ecol. 2025 Jun 24;101(7). doi: 10.1093/femsec/fiaf061.
Increased usage of nanotechnological applications inevitably leads to exposure of hosts and their associated microbiomes to metallic nanoparticles. Various bacteria within the microbiome harbour mechanisms to protect themselves against metal-related toxicity. These mechanisms have been broadly described in the absence of a host. Here, we studied how silver ion-resistant bacteria isolated from the Daphnia magna microbiome shape the host's exposure to silver nanoparticles. With germfree and mono-associated neonates, the effects of these microbes on the sensitivity of D. magna to silver nanoparticles were studied. By using this approach, a core member of the D. magna microbiome Sphingomonas yanoikuyae was identified to be silver-resistant. Neonates mono-associated with S. yanoikuyae were as sensitive to silver nanoparticles as naturally colonized neonates, whereas mono-association with Microbacterium and germfree neonates had increased sensitivity. Silver ions are the major attribution to toxicity in germfree and Microbacterium-associated neonates, whereas particles contribute more to the toxicity for the naturally- and Sphingomonas-colonized neonates. Sphingomonas accumulated in vivo more silver ions from its local environment than the other D. magna bacterial isolates. The current study shows that bacteria can play a vital role in shaping the speciation of nanomaterials and thereby modifying the toxicity to hosts.
纳米技术应用的使用增加不可避免地导致宿主及其相关微生物群落接触金属纳米颗粒。微生物群落中的各种细菌具有保护自身免受金属相关毒性影响的机制。在没有宿主的情况下，这些机制已被广泛描述。在这里，我们研究了从大型溞微生物群落中分离出的抗银离子细菌如何影响宿主对银纳米颗粒的暴露。通过无菌和单菌关联的新生大型溞，研究了这些微生物对大型溞对银纳米颗粒敏感性的影响。通过这种方法，确定了大型溞微生物群落的核心成员雅罗鞘氨醇单胞菌具有抗银性。与雅罗鞘氨醇单胞菌单菌关联的新生大型溞对银纳米颗粒的敏感性与自然定殖的新生大型溞相同，而与微杆菌单菌关联和无菌新生大型溞的敏感性增加。银离子是无菌和与微杆菌关联的新生大型溞中毒性的主要归因，而颗粒对自然定殖和鞘氨醇单胞菌定殖的新生大型溞的毒性贡献更大。与其他大型溞细菌分离株相比，鞘氨醇单胞菌在体内从其局部环境中积累了更多的银离子。目前的研究表明，细菌在塑造纳米材料的形态从而改变对宿主的毒性方面可以发挥至关重要的作用。
