Biopearling of Interconnected Outer Membrane Vesicle Chains by a Marine Flavobacterium
| Autor: | Androniki Kolovou, Erhard Rhiel, Sten Littmann, Stephanie Markert, Jens Harder, Greta Reintjes, Thomas Schweder, Dörte Becher, Rachel Santarella-Mellwig, Martin Schorb, Tanja Fischer |
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| Rok vydání: | 2019 |
| Předmět: |
Proteomics
Aquatic Organisms Vesicle lumen Flavobacterium Applied Microbiology and Biotechnology Extracellular Vesicles 03 medical and health sciences Laminarin chemistry.chemical_compound Environmental Microbiology Secretion Glucans 030304 developmental biology 0303 health sciences Ecology biology 030306 microbiology Vesicle Cell Membrane Eutrophication biology.organism_classification Microscopy Electron Membrane chemistry Liposomes Biophysics Bacterial outer membrane Flavobacteriia Bacterial Outer Membrane Proteins Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 85 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.00829-19 |
| Popis: | Large surface-to-volume ratios provide optimal nutrient uptake conditions for small microorganisms in oligotrophic habitats. The surface area can be increased with appendages. Here, we describe chains of interconnecting vesicles protruding from cells of strain Hel3_A1_48, affiliating with Formosa spp. within the Flavobacteriia and originating from coastal free-living bacterioplankton. The chains were up to 10 μm long and had vesicles emanating from the outer membrane with a single membrane and a size of 80 to 100 nm by 50 to 80 nm. Cells extruded membrane tubes in the exponential phase, whereas vesicle chains dominated on cells in the stationary growth phase. This formation is known as pearling, a physical morphogenic process in which membrane tubes protrude from liposomes and transform into chains of interconnected vesicles. Proteomes of whole-cell membranes and of detached vesicles were dominated by outer membrane proteins, including the type IX secretion system and surface-attached peptidases, glycoside hydrolases, and endonucleases. Fluorescein-labeled laminarin stained the cells and the vesicle chains. Thus, the appendages provide binding domains and degradative enzymes on their surfaces and probably storage volume in the vesicle lumen. Both may contribute to the high abundance of these Formosa-affiliated bacteria during laminarin utilization shortly after spring algal blooms. IMPORTANCE Microorganisms produce membrane vesicles. One synthesis pathway seems to be pearling that describes the physical formation of vesicle chains from phospholipid vesicles via extended tubes. Bacteria with vesicle chains had been observed as well as bacteria with tubes, but pearling was so far not observed. Here, we report the observation of, initially, tubes and then vesicle chains during the growth of a flavobacterium, suggesting biopearling of vesicle chains. The flavobacterium is abundant during spring bacterioplankton blooms developing after algal blooms and has a special set of enzymes for laminarin, the major storage polysaccharide of microalgae. We demonstrated with fluorescently labeled laminarin that the vesicle chains bind laminarin or contain laminarin-derived compounds. Proteomic analyses revealed surface-attached degradative enzymes on the outer membrane vesicles. We conclude that the large surface area and the lumen of vesicle chains may contribute to the ecological success of this marine bacterium. |
| Databáze: | OpenAIRE |
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