PCR-SSCP comparison of 16S rDNA sequence diversity in soil DNA obtained using different isolation and purification methods

A Gram-positive, molinate-degrading bacterium, strain ON4T (=DSM 13485T=LMG 21909T), was isolated from a mixed bacterial culture able to mineralize the herbicide molinate. The strain was strictly aerobic, oxidase- and catalase-positive and non-acid-fast, with a growth temperature of 10–41 °C. It contained the major menaquinone MK-9 and a cell-wall peptidoglycan based on d-ornithine. 16S rDNA sequence analysis revealed that the strain formed a distinct line of descent in the family Microbacteriaceae, showing the highest 16S rDNA similarity (∼95 %) to members of the genus Curtobacterium and ‘Brevibacterium helvolum’ DSM 20419 (=ATCC 13715). The latter was reported to have the cell-wall peptidoglycan type B2γ and the major menaquinone MK-9, which are typical of Clavibacter, but it is clearly separated from this genus at the phylogenetic level. Based on low values of 16S rDNA sequence similarity to previously described genera and their distinctive phenotypic characteristics, it is proposed that strains ON4T and ‘B. helvolum’ DSM 20419 be classified as two novel genera and species, with the respective names Gulosibacter molinativorax gen. nov., sp. nov. and Pseudoclavibater helvolus gen. nov., sp. nov.

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Rothia aeria sp. nov., Rhodococcus baikonurensis sp. nov. and Arthrobacter russicus sp. nov., isolated from air in the Russian space laboratory Mir

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.02828-0 ◽

2004 ◽

Vol 54 (3) ◽

pp. 827-835 ◽

Cited By ~ 72

Author(s):

Ying Li ◽

Yoshiaki Kawamura ◽

Nagatoshi Fujiwara ◽

Takashi Naka ◽

Hongsheng Liu ◽

...

Keyword(s):

16S Rdna ◽

Sequence Similarity ◽

Rhodococcus Erythropolis ◽

Rdna Sequence ◽

Taxonomic Study ◽

16S Rdna Sequence ◽

Gram Positive Bacteria ◽

16S Rdna Sequence Analysis ◽

Rothia Mucilaginosa ◽

Established Species

Four Gram-positive bacteria, strains A1-17BT, A1-22T, A1-3T and A1-8, isolated from the air in the Russian space laboratory Mir, were subjected to a polyphasic taxonomic study. Phylogenetic analysis of the bacteria based on their 16S rDNA sequence showed that they belong to the genera Rothia (A1-17BT), Rhodococcus (A1-22T) and Arthrobacter (A1-3T and A1-8). Morphological, physiological, chemotaxonomic and genomic characteristics supported the assignments of these strains to these genera, but they could not be classified as any existing species within each respective genus. 16S rDNA similarity values between strain A1-17BT and its neighbours, Rothia dentocariosa genomovar II, Rothia dentocariosa, Rothia mucilaginosa and Rothia nasimurium, were respectively 99·8, 98·0, 96·4 and 95·4 %. Polyphasic taxonomic evidence indicated that strain A1-17BT should be categorized together with the unofficially named Rothia dentocariosa genomovar II, but clearly differentiated them from the established species of the genus Rothia. Strain A1-22T formed a coherent cluster with Rhodococcus erythropolis, Rhodococcus globerulus, Rhodococcus marinonascens and Rhodococcus percolatus in 16S rDNA sequence analysis, but DNA–DNA relatedness values were only 45·5, 35·3, 18·9 and 21·9 %. Strains A1-3T and A1-8 shared 99·9 % 16S rDNA sequence similarity, and strain A1-3T showed the highest level of 16S rDNA similarity, 96·6 %, to Arthrobacter polychromogenes. Contrasting biochemical characteristics were also identified. Finally, as a result of the polyphasic taxonomic study, three of the strains are proposed as type strains of novel species: Rothia aeria sp. nov. (A1-17BT=GTC 867T=JCM 11412T=DSM 14556T), Rhodococcus baikonurensis sp. nov. (A1-22T=GTC 1041T=JCM 11411T=DSM 44587T) and Arthrobacter russicus sp. nov. (A1-3T=GTC 863T=JCM 11414T=DSM 14555T).

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