Domain Bacteria Order Fimbriimonadales Genus Fimbriimonas Rank Species | Class Fimbriimonadia Family Fimbriimonadaceae Phylum Armatimonadetes | |
Similar Caldisericum, Nitrosomonadales, Elusimicrobia, Sphaerobacter, Cytophagales | ||
Fimbriimonas ginsengisoli is a Gram-negative bacterium and also the first representative of the new class Fimbriimonadia within the phylum Armatimonadetes. The Armatimonadetes were previously known as candidate phylum OP10. OP10 was composed solely of environmental 16S rRNA gene clone sequences prior to F. ginsengisoli's relative, Armatimonas rosea's discovery.
Contents
Discovery
F. ginsengisoli was originally isolated from a soil sample from a ginseng field in the Pocheon province, South Korea. Cultivation took place on one-half strength R2A agar.
Relatives
The environmental 16S rRNA gene sequences, belonging to the phylum Armatimonadetes are currently sorted into six groups. Groups 2, 5, and 6 consist solely of sequences. Group 1 contains Armatimonadetes rosea, Group 3 contains Chthonomonadetes calidirosea, and Group 4 conatins Fimbriimonas ginsengisoli.
Chthonomonas calidirosea strain T49T, an aerobic, 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 Armatimonadetes. It represents the first cultured representative of the Chthonomonadetes, corresponding with Group 3 of the phylum Armatimonadetes.
Armatimonas rosea an aerobic, Gram-negative, pink pigmented, nonmotile,ovoid/rod shaped bacterium, was isolated from the rhizoplane of an aquatic plan Phragmites australis in Japan. It is the first representative of the phylum Armatimonadetes.
Characteristics
When grown on one-half strength R2A, colonies were ivory pigmented, circular, raised, contained a greasy surface, highly mucoid, and relatively small (1–2 mm) in size after two weeks of incubation at 30oC. F. ginsengisoli has an optimum temperature at 30oC with a range of 15-30oC. The optimum pH for growth was 7.0 with a range of 6.0-8.5. Supplementary NaCl was not needed for growth but concentrations up to 1% could be tolerated.
When examined by phase-contrast and transmission electron microscopy cells were observed to be nonmotile, rod shaped, with sizes ranging from 0.5-0.7 µm in width and 2.5-5.0 µm in length. F. ginsengisoli carried peritrichous fibrils, which were very fine and hairy and projected out from the cell wall. Spore formation was not observed.
When investigated in one-half R2A media, cultures of F. ginsengisoli were observed to be strictly aerobic with no evidence of growth under anaerobic conditions. It is negative for the oxidase test, but positive for the catalase test. It could not use most substrates tested as a sole carbon source but could use peptone, casamino acids or yeast extract as sole carbon sources. The strain did not degrade DNA, starch, xylan, or cellulose.