Deinococcus phoenicis sp. nov., an extreme ionizing-radiation-resistant bacterium isolated from the Phoenix Lander assembly facility.

A bacterial strain, designated 1P10ME(T), which was resistant to extreme doses of ionizing radiation, pale-pink, non-motile, and a tetrad-forming coccoid was isolated from a cleanroom at the Kennedy Space Center, where the Phoenix spacecraft was assembled. Strain 1P10ME(T) showed optimum growth at 30 °C, with a pH range for growth of 6.5-9.0 and was highly sensitive to sodium chloride, growing only in medium with no added NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 1P10ME(T) represents a novel member of the genus Deinococcus, with low sequence similarities (<93.5%) to recognized species of the genus Deinococcus. The predominant cellular fatty acid was C15:1ω6c. This novel strain exhibits extreme resistance to gamma radiation (D10 >8 kGy) and UV (D10 >1000 Jm(-2)). The results of our polyphasic taxonomic analyses suggest that strain 1P10ME(T) represents a novel species of the genus Deinococcus, for which the name Deinococcus phoenicis sp. nov. is proposed. The type strain is 1P10ME(T) ( = NRRL B-59546(T) = DSM 27173(T)).

Description of Tersicoccus phoenicis gen. nov., sp. nov. isolated from spacecraft assembly clean room environments.

Two strains of aerobic, non-motile, Gram-reaction-positive cocci were independently isolated from geographically distinct spacecraft assembly clean room facilities (Kennedy Space Center, Florida, USA and Centre Spatial Guyanais, Kourou, French Guiana). A polyphasic study was carried out to delineate the taxonomic identity of these two isolates (1P05MA(T) and KO_PS43). The 16S rRNA gene sequences exhibited a high similarity when compared to each other (100 %) and lower than 96.7 % relatedness with Arthrobacter crystallopoietes ATCC 15481(T), Arthrobacter luteolus ATCC BAA-272(T), Arthrobacter tumbae DSM 16406(T) and Arthrobacter subterraneus DSM 17585(T). In contrast with previously described Arthrobacter species, the novel isolates maintained their coccidal morphology throughout their growth and did not exhibit the rod-coccus life cycle typically observed in nearly all Arthrobacter species, except A. agilis. The distinct taxonomic identity of the novel isolates was confirmed based on their unique cell-wall peptidoglycan type (A.11.20; Lys-Ser-Ala2) and polar lipid profile (presence of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, an unknown phospholipid and two unknown glycolipids). The G+C content of the genomic DNA was 70.6 mol%. The novel strains revealed MK-9(H2) and MK-8(H2) as dominant menaquinones and exhibited fatty acid profiles consisting of major amounts of anteiso-C15 : 0 and anteiso-C17 : 0 and moderate amounts of iso-C15 : 0 discriminating them again from closely related Arthrobacter species. Based on these observations, the authors propose that strains 1P05MA(T) and KO_PS43 be assigned into a separate genus Tersicoccus gen. nov. For this new taxon, comprising strains 1P05MA(T) and KO_PS43, we propose the name Tersicoccus phoenicis gen. nov., sp. nov. (the type species of Tersicoccus), represented by the type strain Tersicoccus phoenicis 1P05MA(T) ( = NRRL B-59547(T) = DSM 30849(T)).