In this study, we investigated the extracellular reactive sulfur species produced by Shewanella oneidensis MR-1 during growth. The results showed that sulfite is the major extracellular sulfur metabolite released to the growth medium under both aerobic and anaerobic growth conditions. Exogenous sulfite at physiological concentrations protected S. oneidensis MR-1 from hydrogen peroxide toxicity and enhanced tolerance to the beta-lactam antibiotics cefazolin, meropenem, doripenem and ertapenem. These findings suggest that the release of extracellular sulfite is a bacterial defence mechanism that plays a role in the mitigation of environmental stress.

中文翻译：

---

胞外亚硫酸盐对 Shewanella oneidensis MR-1 中的活性氧和抗生素应激具有保护作用

在这项研究中，我们研究了Shewanella oneidensis MR-1 在生长过程中产生的细胞外活性硫物质。结果表明，在好氧和厌氧生长条件下，亚硫酸盐都是释放到生长培养基中的主要细胞外硫代谢物。生理浓度的外源性亚硫酸盐保护S. oneidensis MR-1 免受过氧化氢毒性并增强对 β-内酰胺类抗生素头孢唑啉、美罗培南、多利培南和厄他培南的耐受性。这些发现表明，细胞外亚硫酸盐的释放是一种细菌防御机制，在缓解环境压力方面发挥作用。