Abstract
An ultraviolet-radiation-resistant, Gram-positive, orange-pigmented, thermophilic and strictly aerobic cocci was isolated from Saharan water hot spring in Tunisia. The newly isolated bacterium, designated HAN-23
T
, was identified based on polyphasic taxonomy including genotypic, phenotypic and chemotaxonomic characterization. Phylogenetic analysis based on 16S rRNA gene sequences placed this strain within
Deinococcus
genus. However, strain HAN-23
T
is different from recognized species of the genus
Deinococcus
, showing less than 94.0% similarity values to its closest relatives. The predominant cellular fatty acids determined by gas chromatography were iso-C
15:0
, iso-C
17:0
and iso C
17:1
ω9c. The major respiratory quinone was MK-8. The DNA G + C content was 66.9 mol%. DNA–DNA hybridization measurements revealed low DNA relatedness (6%) between the novel isolate and its closest neighbor, the type strain
Deinococcus geothermalis
DSM 11300. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain HAN-23
T
represents a novel species of the genus
Deinococcus
, for which the name
Deinococcus sahariens
sp. nov. is proposed, the type strain being HAN-23
T
(=DSM 18496
T
; LMG 23756
T
).