Biopearling: Chains of interconnected outer membrane vesicles in a marine flavobacterium

ABSTRACT: 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 the flavobacterial strain Hel3_A1_48 originating from coastal free-living bacterioplankton. The chains were up to 10 µm long, had vesicles with a single membrane and a size of 80-100 nm by 50-80 nm, and emanated from the outer membrane. Cells extruded membrane tubes in the exponential phase, whereas vesicle chains dominated on cells in the stationary growth phase. This indicated a formation by pearling, which describes a physical morphogenic process: membrane tubes are protruding 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. Imported fluorescein-labeled laminarin was present in the periplasm of the cells and in the lumen of protruding vesicle chains. The appendages thus provide degradative enzymes on their surfaces and storage volume in the periplasmic extension, which seems to contribute to the high abundance of the Formosa-affiliated bacteria during laminarin utilization shortly after algal blooms.

INSTRUMENT(S): LTQ Orbitrap Classic

ORGANISM(S): Formosa Sp. Hel3_a1_48

SUBMITTER: Stephanie Markert  

LAB HEAD: Stephanie Markert

PROVIDER: PXD012522 | Pride | 2019-07-25

REPOSITORIES: Pride