Two native ionizing radiation-resistant bacteria
were isolated and identified from a soil sample collected
from extreme conditions of the Lout desert in Iran. The
hottest land surface temperature has been recorded in the
Lout desert from 2004 to 2009. Also, it is categorized as a
hyper arid place. Both ionizing radiation and desiccation
may cause damage on genome. Soil sample was irradiated
in order to eliminate sensitive bacteria then cultured in onetenth-
strength tryptic soy broth medium. Bacterial suspension
used for radiation treatment. Morphological and
physiological characterization and phylogenetic studies
based on
16S rRNA gene sequence were used for identification.
The cells were rod shape, non-motile, non-spore
forming and gram positive. The
16S rRNA gene sequence
showed 99.5 % of similarity to
Deinococcus ficus
. Phylogenetic
dendrogram demonstrated that the isolates branched
with
Deinococcus xibeiensis
,
D. ficus and
Deinococcus mumbaiensis
. Both
isolates were resistant to >15 kGy of gamma radiation and
>600 J m
2 of UV radiation. This is the first report on
radiation resistant bacteria belonging to genus Deinococcus
isolated from the Lout desert of Iran.