干旱区生态环境知识资源中心

A Gram-stain-positive, pink-pigmented, coccus-shaped, strictly aerobic, non-motile bacterium, strain THG-AG1.5(T), was isolated from rhizosphere of Hibiscus syriacus L. (Mugunghwa flower) located in Kyung Hee University, Yongin, Gyeonggi, Republic of Korea. The isolated strain grew optimally at 25-30 degrees C, at pH 6.0-7.5 and in the presence of additional 0-1.5% (w/v) NaCl. Strain THG-AG1.5(T) exhibited tolerance to UV radiation (>1500 J m(-2)) and to gamma radiation (>12 kGy). Based on 16S rRNA gene sequence comparisons, strain THG-AG1.5(T) was closely related to Deinococcus daejeonensis MJ27(T) (98.03 %), Deinococcus radiotolerans C1(T) (97.61 %) and Deinococcus grandis DSM 3963(T) (97.32 %). The genomic DNA G+C content of strain THG-AG1.5(T) was 74.8 mol%. The DNA-DNA hybridization values between strain THG-AG1.5(T) and its closest phylogenetically neighbours were below 63.0 %. The peptidoglycan amino acids were alanine, valine, glutamic acid, glycine, ornithine, lysine and aspartic acid. Strain THG-AG1.5(T) contained ribose, mannose and glucose as whole-cell-wall sugars and menaquinone-8 (MK-8) as the only isoprenoid quinone. The major component in the polyamine pattern was spermidine. The major polar lipids of strain THG-AG1.5(T) were a phosphoglycolipid, six unidentified glycolipids and an unidentified aminophospholipid. The major fatty acids were identified as iso-C-15 : 0, C-15 : 1 omega 6c, C-16 : 0, iso-C-17 : 0, C-17 : 0, C-18 : 0 and summed feature 3. On the basis of our polyphasic taxonomy study, strain THG-AG1.5(T) represents a novel species within the genus Deinococcus, for which the name Deinococcus hibisci sp. nov. is proposed. The type strain is THG-AG1.5(T) (=KACC 18850(T)=CCTCC AB 2016078(T)).