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Collection, Isolation and Enrichment of Naturally Occurring Magnetotactic Bacteria from the Environment
Published on: November 15, 2012
Intracellular manganese granules formed by a subsurface bacterium
Susan Glasauer1, Sean Langley, Terry J Beveridge
1Department of Land Resource Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada. glasauer@uoguelph.ca
Environmental Microbiology
|September 4, 2004
Summary
This study reveals bacteria can form intracellular manganese (Mn) oxide particles during anaerobic respiration, a novel finding for microbial metal metabolism. These manganese deposits occur in the cytoplasm and periplasm, not the outer membrane.
Area of Science:
- Microbiology
- Biogeochemistry
- Environmental Science
Background:
- Prokaryotes are known to form intracellular iron (Fe) oxide particles.
- Mineral-bound manganese (Mn(IV)) acts as an electron acceptor for microbial anaerobic respiration.
- Intracellular Mn deposits have not been previously reported in bacteria.
Purpose of the Study:
- To investigate the potential for bacteria to form intracellular manganese (Mn) solids during anaerobic respiration.
- To characterize the location and conditions of Mn precipitation in Shewanella putrefaciens.
Main Methods:
- Culturing Shewanella putrefaciens with Mn(IV) oxides (birnessite, pyrolusite) as electron acceptors.
- Microscopic analysis to identify and localize Mn precipitates.
- Assessing Mn accumulation in different cellular compartments.
Main Results:
- Distinct, nanometer-sized Mn-rich granules were observed within the bacterial cytoplasm.
- Additional Mn precipitates formed in the periplasm during rapid Mn reduction.
- No detectable Mn accumulation was found in the bacterial outer membrane.
Conclusions:
- This research reports the first instance of intracellular Mn solid formation by bacteria coupled to anaerobic respiration.
- The findings expand our understanding of microbial metal oxide biomineralization and biogeochemical cycling.
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