''Armatimonas rosea'' is a Gram-negative bacterium and also the first species to be characterized within the phylum Armatimonadota. The Armatimonadota were previously known as candidate phylum OP10. OP10 was composed solely of environmental 16S rRNA gene clone sequences prior to ''A. rosea's'' discovery.
Discovery
''A. rosea'' was originally isolated from the rhizoplane of the aquatic plant ''
Phragmites australis
''Phragmites australis'', known as the common reed, is a species of plant. It is a broadly distributed wetland grass that can grow up to tall.
Description
''Phragmites australis'' commonly forms extensive stands (known as reed beds), which may ...
'' inhabiting a freshwater lake in the
Yamanashi prefecture
is a prefecture of Japan located in the Chūbu region of Honshu. Yamanashi Prefecture has a population of 817,192 (1 January 2019) and has a geographic area of 4,465 km2 (1,724 sq mi). Yamanashi Prefecture borders Saitama Prefecture to the no ...
in Japan. Cultivation and isolation were completed in a low nutrient medium, DTS.
Relatives
The environmental 16S rRNA gene sequences belonging to the phylum ''Armatimonadota'' are currently sorted into six groups. Groups 2, 5, and 6 consist solely of sequences. Group 1 contains ''Armatimonas rosea'', Group 3 contains ''Chthonomonadetes calidirosea'', and Group 4 contains ''Fimbriimonas ginsengisoli''.
''Chthonomonas calidirosea'' strain T49T, an
aerobic
Aerobic means "requiring air," in which "air" usually means oxygen.
Aerobic may also refer to
* Aerobic exercise, prolonged exercise of moderate intensity
* Aerobics, a form of aerobic exercise
* Aerobic respiration, the aerobic process of cellu ...
, saccharolytic, obligately thermophilic, motile, non-spore-forming bacterium, was isolated from geothermally heated soil at Hell's Gate, Tikitere, New Zealand. It is the first representative of a new class in the phylum ''Armatimonadota''. It represents the first cultured representative of the ''Chthonomonadetes'', corresponding with Group 3 of the phylum ''Armatimonadota''.
''Fimbriimonas ginsengisoli'', an aerobic, non-motile, mesophilic, rod-shaped bacterium, was isolated from a ginseng field soil sample. It represents the first cultured representative of the ''Fimbriimonadia'' class, corresponding with Group 4 of the phylum ''Armatimonadota''.
Characteristics
When grown on the relatively low-nutrient medium, R2A, colonies were pink pigmented, circular, smooth, significantly hard, relatively small (1–2 mm) in size after one week of incubation at 30 °C. ''A.rosea'' has an optimum temperature at 30–35 °C with a range of 20–40 °C. The optimum pH for growth was 6.5 with a range of 5.5–8.5. It is able to tolerate NaCl concentrations up to 0.5%.
When examined by
phase-contrast
__NOTOC__
Phase-contrast microscopy (PCM) is an optical microscopy technique that converts phase shifts in light passing through a transparent specimen to brightness changes in the image. Phase shifts themselves are invisible, but become visible ...
and transmission electron microscopy cells were observed to be nonmotile, ovoid to rod shaped, with sizes ranging from 1.4 to 1.8 µm in width and 2.4–3.2 µm in length. Neither spores nor flagella were observed.
When investigated in R2A media, cultures of ''A. rosea'' were observed to be aerobic and
chemoheterotrophic
A Chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic ( chemoorganotrophs) or inorganic (chemolithotrophs). The chemotroph designation is in contrast to phototro ...
with no evidence of growth under anaerobic conditions. It is negative for the following tests: nitrate respiration, fermentative growth, catalase, and cytochrome oxidase.
References
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External links
Type strain of ''Armatimonas rosea'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q4792902
Gram-negative bacteria
Bacteria described in 2011