A representative genomic 16S rRNA sequence of strain LB-34T
was compared using NCBI BLAST under default settings (e.g., considering only the high-scoring segment pairs (HSPs) from the best 250 hits) with the most recent release of the Greengenes database [23
] and the relative frequencies, weighted by BLAST scores, of taxa and keywords (reduced to their stem [24
]) were determined. The single most frequent genus was Deinococcus
(100.0%) (114 hits in total). Regarding the three hits to sequences from members of the species, the average identity within HSPs was 99.9%, whereas the average coverage by HSPs was 97.6%. Regarding the 77 hits to sequences from other members of the genus, the average identity within HSPs was 91.5%, whereas the average coverage by HSPs was 60.5%. Among all other species, the one yielding the highest score was D. radiodurans
, which corresponded to an identity of 91.2% and an HSP coverage of 88.0%. The highest-scoring environmental sequence was AY905380 ('Extensive ionizing-radiation-resistant recovered sonoran and description nine new species genus Deinococcus
obtained single mixed agricultural/open desert soil clone L14-471'), which showed an identity of 98.1% and a HSP coverage of 70.2%. The five most frequent keywords within the labels of environmental samples which yielded hits were 'skin' (7.7%), 'litholog/stream' (2.8%), 'fossa' (2.4%), 'microbi' (2.4%) and 'forearm' (2.1%) (136 hits in total). Environmental samples which yielded hits of a higher score than the highest scoring species were not found.
shows the phylogenetic neighborhood of D. maricopensis LB-34T in a 16S rRNA based tree. The sequences of the four identical 16S rRNA gene copies in the genome differ by one nucleotide from the previously published 16S rRNA sequence (AY743274).
Figure 1 Phylogenetic tree highlighting the position of D. maricopensis relative to the other type strains within the family Deinococcaceae. The tree was inferred from 1,382 aligned characters [25,26] of the 16S rRNA gene sequence under the maximum likelihood (more ...)
The cells of D. maricopensis
are rod-shaped, up to 6 µm in length and 2.0 µm wide (). D. maricopensis
is a Gram-positive, non-spore-forming bacterium (). Colonies on Rich medium are orange to pink. The cells are non-motile. The organism is chemoorganotrophic [1
]. The temperature range for growth is 10° to 45°C, with an optimum at 40°C [1
]. Cytochrome oxidase and catalase activity have been observed [1
]. Strains may utilize L-arabinose, cellobiose, galactose, glucose, mannose, maltose, sucrose, trehalose, glucosamine, glycerol, malate, asparagine, aspartate, glutamate, L-glutamine, ornithine and proline. Fructose can be used by strain KR23, but not by strain LB-34T
]. Strain LB-34T
showed similar levels of desiccation tolerance of up to four weeks as compared to D. radiodurans
. Strain LB-34T
is resistant to > 10kGy, but more sensitive to ionizing radiation than strain D. radiodurans
Scanning electron micrograph of D. maricopensis LB-34T
Table 1 Classification and general features of D. maricopensis LB-34Taccording to the MIGS recommendations .
The major cellular fatty acids of the strain LB-34T
were identified as iso
. Menaquinone 8 (MK-8) was determined as the major respiratory quinone of the strain. Phosphoglycolipid and glycolipid pattern are similar to those of other Deinococcus
]. No data are available for strain LB-34T
showing the peptidoglycan type of the cell wall.