Jung Deborah O, Achenbach Laurie A, Karr Elizabeth A, Takaichi Shinichi, Madigan Michael T
Department of Microbiology, Southern Illinois University, Carbondale, IL 62901-6508, USA.
Arch Microbiol. 2004 Oct;182(2-3):236-43. doi: 10.1007/s00203-004-0719-8. Epub 2004 Aug 31.
A moderately psychrophilic purple non-sulfur bacterium, Rhodoferax antarcticus strain Fryx1, is described. Strain Fryx1 was isolated from the water column under the ice of the permanently frozen Lake Fryxell, Antarctica. Cells of Fryx1 are long thin rods and contain gas vesicles, the first report of such structures in purple non-sulfur bacteria. Gas vesicles are clustered at 2-4 sites per cell. Surprisingly, the 16S rRNA gene sequence of strain Fryx1 is nearly identical to that of Rfx. antarcticus strain AB, a short, vibrio-shaped phototroph isolated from an Antarctic microbial mat. Although showing physiological parallels, strains AB and Fryx1 differ distinctly in their morphology and absorption spectra. DNA-DNA hybridization shows that the genomes of strains AB and Fryx1 are highly related, yet distinct. We conclude that although strains AB and Fryx1 may indeed be the same species, their ecologies are quite different. Unlike strain AB, strain Fryx1 has adapted to a planktonic existence in the nearly freezing water column of Lake Fryxell.
描述了一种中度嗜冷的紫色非硫细菌——南极红杆菌Fryx1菌株。Fryx1菌株是从南极常年冰封的弗里克塞尔湖冰层下的水柱中分离出来的。Fryx1的细胞是细长杆状，含有气体泡囊，这是紫色非硫细菌中首次报道有此类结构。气体泡囊在每个细胞中聚集在2至4个位点。令人惊讶的是，Fryx1菌株的16S rRNA基因序列与南极红杆菌AB菌株几乎相同，AB菌株是从南极微生物垫中分离出的一种短的、弧状光合生物。尽管在生理上有相似之处，但AB菌株和Fryx1菌株在形态和吸收光谱上有明显差异。DNA-DNA杂交表明，AB菌株和Fryx1菌株的基因组高度相关，但又有所不同。我们得出结论，尽管AB菌株和Fryx1菌株可能确实是同一物种，但它们的生态习性却大不相同。与AB菌株不同，Fryx1菌株已经适应了在弗里克塞尔湖几乎结冰的水柱中以浮游生物的形式生存。
