Downloaded from www.microbiologyresearch.org by IP: 54.92.220.51 On: Sun, 16 Oct 2016 21:22:25 Deinococcus depolymerans sp. nov., a gamma- and UV-radiation-resistant bacterium, isolated from a naturally radioactive site Dalal Asker, 1,2,3 Tarek S. Awad, 3 Lynne McLandsborough, 3 Teruhiko Beppu 1 and Kenji Ueda 1 Correspondence Dalal Asker dasker10@gmail.com 1 Life Science Research Center, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa 252-8510, Japan 2 Food Science and Technology Department, Faculty of Agriculture, Alexandria University, 21545 – El-Shatby, Alexandria, Egypt 3 Department of Food Science, University of Massachusetts, 100 Holdsworth Way, Amherst, MA 01003, USA Four gamma- and UV-radiation-resistant bacterial strains, designated TDMA-24 T , TDMA-24-2, TDMA-24-3 and TDMA-24-4, were isolated from a fresh-water sample collected at Misasa, Tottori, Japan. Cells of these strains were Gram-reaction-positive, non-motile, non-spore-forming, rod-shaped and formed red colonies. The genomic DNA G+C contents ranged from 70.5 to 70.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolates belong to the genus Deinococcus, the highest sequence similarities being with Deinococcus aquaticus PB314 T (98 %) and Deinococcus caeni Ho-08 T (97 %). The polar lipid profile of strain TDMA-24 T comprised three unidentified phosphoglycolipids, five unidentified glycolipids and seven unidentified polar lipids. MK-8 was the predominant respiratory quinone. Major fatty acids were iso-C 15 : 0 ,C 15 : 1 v6c,C 15 : 0 ,C 16 : 0 and summed feature 3 (iso-C 15 : 0 2-OH and/or C 16 : 1 v7c). On the basis of their phylogenetic positions and chemotaxonomic and phenotypic characteristics, the novel isolates represent a novel species of the genus Deinococcus, for which the name Deinococcus depolymerans sp. nov. is proposed. The type strain is TDMA-24 T (5JCM 14369 T 5NBRC 102115 T 5CCUG 53609 T ). The genus Deinococcus (Battista & Rainey, 2001; Brooks & Murray, 1981; Rainey et al., 1997) belongs to the family Deinococcaceae (Battista & Rainey, 2001; Brooks & Murray, 1981; Rainey et al., 1997) and comprises .40 species, 26 of which have been described as being highly resistant to radiation (Asker et al., 2008, 2009; de Groot et al., 2005; Hirsch et al., 2004; Im et al., 2008; Lai et al., 2006; Rainey et al., 2005; Suresh et al., 2004; Zhang et al., 2007). Four other species of the genus Deinococcus have been described as being sensitive to ionizing radiation (Callegan et al., 2008). Four gamma- and UV-radiation-resistant bacterial strains, designated TDMA-24 T , TDMA-24-2, TDMA-24-3 and TDMA-24-4, which produce unknown carotenoids and form red-pigmented colonies, were isolated from the Misasa spa, Tottori, Japan, a region known for its high levels of natural radioactivity (Asker et al., 2007a, b). Based on 16S rRNA gene sequence similarities (Asker et al., 2007b) these strains were phylogenetically identical (100 % sequence similarity). Here, we report the results of a polyphasic taxonomic study on the four novel strains. On the basis of their biochemical and chemical characteristics and the results of 16S rRNA gene sequence analysis, we propose that the isolates represent a novel species within the genus Deinococcus. Strains TDMA-24 T , TDMA-24-2, TDMA-24-3 and TDMA-24-4 were isolated as described by Asker et al. (2007b), except that incubations were carried out at 30 u C. Genomic DNA of the isolates was extracted using a bacterial genomic DNA purification kit (Edge BioSystems). DNA fragments containing the nearly complete 16S rRNA gene sequence were amplified according to the method described previously by Asker et al. (2007b). The 16S rRNA genes were sequenced directly by using a BigDye Terminator v3.1 cycle sequencing kit and an ABI 3100 Abbreviation: RAPD, random amplification of polymorphic DNA. The GenBank/EMBL/DDBJ/accession numbers for the 16S rRNA gene sequences of strains TDMA-24 T , TDMA-24-2, TDMA-24-3 and TDMA-24-4 are AB264134, AB479215, AB479216 and AB479217. Four supplementary figures and one supplementary table are available with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2011), 61, 1448–1453 DOI 10.1099/ijs.0.013482-0 1448 013482 G 2011 IUMS Printed in Great Britain