Spirochaete
From Free net encyclopedia
{{Taxobox
| color = lightgrey
| name = Spirochaetes
| image = Treponema_pallidum_01.png
| image_width = 240px
| image_caption = Treponema pallidum spirochetes.
| regnum = Bacteria
| phylum = Spirochaetes
| classis = Spirochaetes
| ordo = Spirochaetales
| ordo_authority = Buchanan 1917
| subdivision_ranks = Families
| subdivision =
Spirochaetaceae
Brachyspiraceae
Brachyspira
Serpulina
Leptospiraceae
Leptospira
Leptonema
}}
The spirochaetes (or spirochetes) are a phylum of distinctive bacteria, which have long, helically coiled cells. They are distinguished by the presence of flagella running lengthwise between the cell membrane and cell wall, called axial filaments. These cause a twisting motion which allows the spirochaete to move about. Most spirochaetes are free-living and anaerobic, but there are numerous exceptions.
It has been suggested by Lynn Margulis that eukaryotic flagella were derived from symbiotic spirochaetes, but few biologists accept this, as there is no close structural similarity between the two.
The spirochaetes are divided into three families, all placed within a single order. Important members of this phylum include
- Leptospira species, which causes leptospirosis,
- Borrelia burgdorferi, which causes Lyme disease, and
- Treponema pallidum, which causes syphilis.
References
External links
de:Spirochäten es:Spirochaetes fr:Spirochaetes lt:Spirochetos nl:Spirocheten ja:スピロヘータ zh:螺旋體門