Redox-Reactive Membrane Vesicles produced by Shewanella
Dissimilatory iron reducing bacteria produce and release membrane vesicles with diameters ranging from 50 to 250 nm. The vesicles, which arise from the outer membrane of these Gram-negative bacteria, lack DNA but contain proteins that catalyze the reduction of ferric iron and other multivalent heavy metals and radionuclides. This enzymatic process results in the formation of nano-size biogenic mineral assemblages that resemble nanofossils. Under low-shear conditions, membrane vesicles are commonly tethered to intact cells by electrically conductive filaments known as bacterial nanowires. The functional role of membrane vesicles and associated nanowires is not known, but the potential for mineralized vesicles that morphologically resemble nanofossils to serve as paleontological indicators of early life on earth and as biosignatures of like on other planets is recognized.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 947904
- Report Number(s):
- PNNL-SA-57721; 25711; KP1302000
- Journal Information:
- Geobiology, 6(3):232-241, Journal Name: Geobiology, 6(3):232-241 Journal Issue: 3 Vol. 6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Formation and Reactivity of Biogenic Iron Microminerals
Redox-linked conformation change and electron transfer between monoheme c-type cytochromes and oxides