Abstract:
:Magnetotactic bacteria are microorganisms that respond to magnetic fields. We studied the surface ultrastructure of uncultured magnetotactic cocci collected from a marine environment by transmission electron microscopy using freeze-fracture and freeze-etching. All bacteria revealed a Gram-negative cell wall. Many bacteria possessed extensive capsular material and a S-layer formed by particles arranged with hexagonal symmetry. No indication of a metal precipitation on the surface of these microorganisms was observed. Numerous membrane vesicles were observed on the surface of the bacteria. Flagella were organized in bundles originated in a depression on the surface of the cells. Occasionally, a close association of the flagella with the magnetosomes that remained attached to the replica was observed. Capsules and S-layers are common structures in magnetotactic cocci from natural sediments and may be involved in inhibition of metal precipitation on the cell surface or indirectly influence magnetotaxis.
journal_name
FEMS Microbiol Lettjournal_title
FEMS microbiology lettersauthors
Freitas F,Keim CN,Kachar B,Farina M,Lins Udoi
10.1016/S0378-1097(02)01187-4keywords:
subject
Has Abstractpub_date
2003-02-14 00:00:00pages
33-8issue
1eissn
0378-1097issn
1574-6968pii
S0378109702011874journal_volume
219pub_type
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