Deinococcus aetherius sp. nov., isolated from the stratosphere

Abstract

A pink-red pigmented, non-motile, coccoid bacterial strain, ST0316 T , was isolated from dust samples collected from the stratosphere in Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that it belonged to the genus Deinococcus. DNA G+C content (69.8 mol%), desiccation tolerance, and resistance to gamma-rays [D 10 (dose required to reduce the bacterial population by 10-fold Members of the genus Deinococcus, which houses 34 species at the time of writing, are known to be desiccation-and radiation-resistant, and have been isolated from various natural environments. It has been suggested that deinococci may become airborne and be distributed throughout the environment (Battista & Rainey, 2001). Actually, some strains belonging to the genus Deinococcus have been isolated from air dust sources (Murray & Robinow, 1958;Christensen & Kristensen, 1981; Weon et al., 2007;Yang et al., 2009). In a previous study, we obtained a novel UVresistant strain from an air dust sample collected in the stratosphere (Yang et al., 2008). Here we report the detailed characterization of this isolate, ST0316 T .We tested the growth of strain ST0316 T on nutrient agar no. 2 (10.0 g peptone, 10.0 g meat extract and 5.0 g NaCl per litre, pH 7.0±0.2), Difco nutrient (3.0 g beef extract, 5.0 g peptone per litre, pH 6.8±0.2), ATCC medium 86 (Difco nutrient with 1 % glucose), Degryse medium 162 (Degryse et al., 1978), TGY (1 % tryptone, 0.1 % glucose, 0.5 % yeast extract, pH 7.0±0.2) and mTGE (6.0 g beef extract, 10.0 g tryptone, 2.0 g glucose per litre, pH 7.0±0.2). Like some deinococcal isolates from the Sonoran Desert (Rainey et al., 2005), ST0316 T grew extremely slowly or not at all in liquid media. Its growth on solid agar containing the above nutrients was also slow, although faster than in the respective liquid medium. Addition of glycerol (0.5 %) and KH 2 PO 4 (0.1 mM) to mTGE agar (namely mTGE-GP) slightly accelerated its growth. Unless stated otherwise, ST0316T cells used in this study were obtained from cultures grown for 3 weeks on mTGE-GP, incubated in the dark at 30 u C. Growth temperatures were measured by spreading cells on mTGE-GP, incubating at 4, 10, 15, 20, 23, 25, 28, 30, 32, 35, 40, 42 or 45 u C for 4 weeks, and checking the development of colonies on the agar plates. The pH range for growth was determined on mTGE-GP plates with the medium buffered between pH 5.8 and pH 8.0 (0.2 pH unit intervals) with 10 mM potassium phosphate buffer.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain ST0316T is AB087287.A graph showing gamma-ray resistance of strain ST0316 T , polar lipid profiles, and phenotypic characteristics and fatty acid compositions of strain ST0316T and the type strains of the closest related species of the genus Deinococcus are available with the online version of this paper.

Deinococcus humi sp. nov., isolated from soil

“…T was isolated without using radiation for selection, it was still found to be radiationresistant (see also Yang et al, 2009Yang et al, , 2010Yoo et al, 2010;Srinivasan et al, 2012).…”

Tanpopo: Astrobiology Exposure and Micrometeoroid Capture Experiments— Proposed Experiments at the Exposure Facility of ISS-JEM

“…The genes of the isolated microbes were analyzed. The analysis revealed that the isolates belong to spore formers (Streptomices, Bacillus and Paenibacillus) and Deinococcus related species [9][10][11] .…”

“…The flux of UV light at high atmosphere is expected to be much higher than ground surface. Accordingly, it is reasonable that the microbes isolated at high atmosphere show high UV resistance [9][10][11] . We have also conducted microbe-sampling experiments using balloons.…”

“…We and other groups have been analyzing the presence of microbes at high atmosphere using aircrafts and balloons [6][7][8][9][10][11][12] . Microbes have been captured by these experiments.…”

Radiation resistant of native Deinococcus spp. isolated from the Lout desert of Iran “the hottest place on Earth”

“…Many members of Deinococcus genus were found in deserts; such as Deinococcus deserti (de Groot et al 2005), Deinococcus peraridilitoris (Rainey et al 2007), Deinococcus gobiensis (Yuan et al 2009) and Deinococcus xinjiangensis (Peng et al 2009). Deinococcus members have been found from harsh places such as radiation polluted places (Asker et al 2009;Wang et al 2010), atmosphere, stratosphere (Yang et al 2010) and Antarctica (Hirsch et al 2004). Environmental conditions in these places cause different kinds of damages to the DNA of organisms.…”