Noundou Vadesse L, Levy Amalie, Modla Shannon, Yu Yanbao, Qu Jing, Hanson Thomas E
Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
Delaware Biotechnology Institute, Newark, DE, 19713, USA.
bioRxiv. 2025 May 13:2024.09.30.615447. doi: 10.1101/2024.09.30.615447.
Outer membrane-derived vesicles (OMVs) have been studied in different phyla of Gram-negative bacteria, most extensively in the Pseudomonadota, where they have been shown to participate in diverse biological and environmental processes. To date, the production of OMVs has not been reported in the Chlorobiaceae within the phylum Chlorobiota. is the model organism for the Chlorobiaceae that synthesizes and consumes insoluble extracellular sulfur (S(0)) globules by an unknown mechanism. Here, we report evidence implicating outer membrane vesicles in biogenic S(0) globule synthesis. We demonstrate that secretes OMVs in the extracellular milieu, and that OMV concentration and size vary with growth conditions, particularly sulfide concentration. A core of 31 proteins involved in diverse biological processes such as cell wall biogenesis, inorganic ion transport and metabolism were found to be shared between OMVs, extracellular S(0) globules and intact cells. Multiple analytical methods indicated that OMVs contain S(0) and that OMVs and biogenic S(0) globules share protein and polysaccharide signatures, including lipooligosaccharides. Together these lines of evidence indicate that 's OMVs are one component of sulfur transport between cells and extracellular sulfur globules.
外膜衍生囊泡（OMVs）已在革兰氏阴性菌的不同门类中得到研究，在假单胞菌门中研究最为广泛，在该门类中它们已被证明参与多种生物和环境过程。迄今为止，尚未有关于绿菌门绿菌科中OMVs产生的报道。绿硫菌是绿菌科的模式生物，它通过一种未知机制合成并消耗不溶性细胞外硫（S(0)）球粒。在此，我们报告了外膜囊泡参与生物源S(0)球粒合成的证据。我们证明绿硫菌在细胞外环境中分泌OMVs，并且OMV的浓度和大小随生长条件而变化，特别是硫化物浓度。在OMVs、细胞外S(0)球粒和绿硫菌完整细胞之间发现了31种参与多种生物过程（如细胞壁生物合成、无机离子运输和代谢）的核心蛋白质。多种分析方法表明OMVs含有S(0)，并且OMVs和生物源S(0)球粒具有共同的蛋白质和多糖特征，包括脂寡糖。这些证据共同表明，绿硫菌的OMVs是细胞与细胞外硫球粒之间硫运输的一个组成部分。
