Development of strain-specific PCR primers for the identification of Fusobacterium nucleatum subsp. fusiforme ATCC 51190T and subsp. vincentii ATCC 49256T

The objective of this study was to develop the strain-specific PCR primers for Fusobacterium nucleatum subsp. fusiforme ATCC 51190^T and F. nucleatum subsp. vincentii ATCC 49256^T based on the nucleotide sequence of the Fs17 and Fv35 DNA probes, respectively. The strain specificity was tested against 10 type strains of Fusobacterium spp. or subsp., 21 clinical isolates of F. nucleatum from Koreans, and five type strains of distinct Fusobacterium species. Primer sensitivity was determined by testing serial dilutions (4 ng–4 fg) of the purified genomic DNA from each of the type strains. PCR showed that two pairs of PCR primers, Fs17-F14/Fs17-R14 and Fv35-F1/Fv35-R1 primers, could produce strain-specific amplicons from F. nucleatum subsp. fusiforme ATCC 51190^T and F. nucleatum subsp. vincentii ATCC 49256^T, respectively. The two PCR primer sets could detect as little as 0.4 pg or 4 pg of the genomic DNA of each target strain. These results suggest that the two sets of PCR primers could be used to identify F. nucleatum subsp. fusiforme ATCC 51190^T and F. nucleatum subsp. vincentii ATCC 49256^T, particularly for ascertaining the authenticity of the strain.     

Salinivibrio costicola subsp. alcaliphilus subsp. nov., a haloalkaliphilic aerobe from Campania Region (Italy)

Phenotypic and phylogenetic studies were performed on unidentified Gram-negative staining, haloalkaliphilic aerobe and protease producer Salinivibrio-like organism recovered from a saltish spring with algal mat in the “Pozzo del Sale” site (Salt's Well) in the Campania Region (South Italy). Phylogenetic analysis based on comparison of 16S rRNA gene sequences demonstrated that the isolate was related to species of Salinivibrio genus. The DNA–DNA hybridization of the type strain 18AG^T with the most related Salinivibrio costicola subsp. costicola showed a re-association value of 72%. Based on the phenotypic distinctiveness of 18AG^T strain and molecular, chemical and genetic evidence, it is proposed that strain 18AG^T can be classified as S. costicola subsp. alcaliphilus, subsp. nov. The type strain of S. costicola subsp. alcaliphilus, is ATCC BAA-952^T; DSM 16359^T.     

Verminephrobacter aporrectodeae sp. nov. subsp. tuberculatae and subsp. caliginosae, the specific nephridial symbionts of the earthworms Aporrectodea tuberculata and A. caliginosa

Clone library-based studies have shown that almost all lumbricid earthworm species harbour host-specific symbiotic bacteria belonging to the novel genus Verminephrobacter in their nephridia (excretory organs). To date the only described representative from this genus is Verminephrobacter eiseniae, the specific symbiont of the earthworm Eisenia fetida. In this study two novel rod-shaped, non-endosporeforming, betaproteobacterial symbionts were isolated from the nephridia of two closely related earthworm species. Both isolates were affiliated with the genus Verminephrobacter by 16S rRNA gene sequence analysis. Similarly to V. eiseniae, the two isolates grew aerobically with a preference for low oxygen concentrations on a range of sugars, fatty acids and amino acids and fermentatively on glucose and pyruvate. These phenotypes match well with the conditions reported or inferred for the nephridial environment. Based on 16S rRNA gene similarity, DNA–DNA hybridization value and phenotypic characteristics the two isolates are clearly distinct from V. eiseniae. Phenotypic characteristics could not clearly differentiate the two strains as separate species but a low DNA–DNA hybridization value of 57.3%, their earthworm host specificity, differing temperature ranges and pH optima suggest that they represent two subspecies of a novel species of Verminephrobacter. For this species, the name V. aporrectodeae sp. nov. is proposed, with the two subspecies V. aporrectodeae subsp. tuberculatae (type strain, At4^T = DSM 21361^T = LMG 25313^T) and V. aporrectodeae subsp. caliginosae (type strain, Ac9^T = DSM 21895^T = LMG 25312^T) isolated from the nephridia of the earthworms Aporrectodea tuberculata and A. caliginosa, respectively.     

Pseudomonas sihuiensis sp. nov., isolated from a forest soil in South China

A Gram-stain negative, motile, rod-shaped bacterium, designated strain WM-2^T, was isolated from a forest soil in Sihui City, South China, and characterized by means of a polyphasic approach. Growth occurred with 0–5 % (w/v) NaCl (optimum 0–1 %) and at pH 5.0–10.5 (optimum pH 8.5) and 4–40 °C (optimum 30 °C) in Luria–Bertani medium. Comparative 16S rRNA gene sequence analyses showed that strain WM-2^T is a member of the genus Pseudomonas and most closely related to P. guguanensis, P. oleovorans subsp. lubricantis, P. toyotomiensis, P. alcaliphila and P. mendocina with 97.1–96.6 % sequence similarities. In terms of gyrB and rpoB gene sequences, strain WM-2^T showed the highest similarity with the type strains of the species P. toyotomiensis and P. alcaliphila. The DNA–DNA relatedness values of strain WM-2^T with P. guguanensis and P. oleovorans subsp. lubricantis was 48.7 and 37.2 %, respectively. Chemotaxonomic characteristics (the main ubiquinone Q-9, major fatty acids C_18:1 ω7c/C_18:1 ω6c, C_16:0 and C_16:1 ω7c/C_16:1 ω6c and DNA G+C content 65.2 ± 0.7 mol%) were similar to those of members of the genus Pseudomonas. Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unknown aminophospholipid, an unknown phospholipid and five unknown lipids. According to the results of polyphasic analyses, strain WM-2^T represents a novel species in the genus Pseudomonas, for which the name Pseudomonas sihuiensis sp. nov. is proposed. The type strain is WM-2^T (=KCTC 32246^T=CGMCC 1.12407^T).     

Control of the pyrimidine biosynthetic pathway in Pseudomonas pseudoalcaligenes

The five de novo enzyme activities unique to the pyrimidine biosynthetic pathway were found to be present in Pseudomonas pseudoalcaligenes ATCC 17440. A mutant strain with 31-fold reduced orotate phosphoribosyltransferase (encoded by pyrE) activity was isolated that exhibited a pyrimidine requirement for uracil or cytosine. Uptake of the nucleosides uridine or cytidine by wild-type or mutant cells was not detectable; explaining the inability of the mutant strain to utilize either nucleoside to satisfy its pyrimidine requirement. When the wildtype strain was grown in the presence of uracil, the activities of the five de novo enzymes were depressed. Pyrimidine limitation of the mutant strain led to the increase in aspartate transcarbamoylase and dihydroorotate dehydrogenase activities by more than 3-fold, and dihydroorotase and orotidine 5-monophosphate decarboxylase activities about 1.5-fold, as compared to growth with excess uracil. It appeared that the syntheses of the de novo enzymes were regulated by pyrimidines. In vitro regulation of aspartate transcarbamoylase activity in P. pseudoalcaligenes ATCC 17440 was investigated using saturating substrate concentrations; transcarbamoylase activity was inhibited by P_i, PP_i, uridine ribonucleotides, ADP, ATP, GDP, GTP, CDP, and CTP.     

Quantitative real-time PCR detection of Pseudomonas oleovorans subsp. lubricantis using TaqMan-MGB assay in contaminated metalworking fluids

Metalworking fluids (MWFs) are highly prone to microbial contamination, which leads to their degradation and biofouling. Pseudomonas oleovorans subsp. lubricantis, a newly described subspecies, was found to be important to MWF fouling. However, the actual distribution of P. oleovorans subsp. lubricantis in MWF is difficult to study using standard culturing techniques. To overcome this, a study was conducted to design a specific quantitative real-time PCR (qPCR) assay using TaqMan^®MGB (minor groove binding) probe for its identification and estimated quantification in contaminated MWFs. The gyrB housekeeping gene sequence was selected for designing a TaqMan^® MGB primer-probe pair using the Allele ID^® 5.0 probe design software for the assay. Whole-cell qPCR was performed with MWF spiked directly with P. oleovorans subsp. lubricantis (eliminating DNA extractions using commercial kit); the primer-probe pair’s sensitivity was 10¹ colony forming units (CFU) ml⁻¹. The assay provided no amplification with other closely related Pseudomonas species found in MWFs indicating its specificity. It was successful in identifying and enumerating P. oleovorans subsp. lubricantis from several used MWFs having between 10⁴ and 10⁶ CFU ml⁻¹. The designed TaqMan^® MGB probe thus can be successfully used for the subspecies-specific identification of P. oleovorans subsp. lubricantis and facilitates the study of its impact on MWFs.     

Oleispira lenta sp. nov., a novel marine bacterium isolated from Yellow sea coastal seawater in Qingdao, China

The taxonomic position of strain DFH11^T, which was isolated from coastal seawater off Qingdao, People’s Republic of China in 2007, was determined. Strain DFH11^T comprised Gram-negative, motile, strictly aerobic spirilli that did not produce catalase. Comparative 16S rRNA gene sequence analysis revealed that strain DFH11^T shared ~97.2, 93.3, 91.8, 91.7 and 91.5% sequence similarities with Oleispira antarctica, Spongiispira norvegica, Bermanella marisrubri, Oceaniserpentilla haliotis and Reinekea aestuarii, respectively. DNA–DNA hybridization experiments indicated that the strain was distinct from its closest phylogenetic neighbour, O. antarctica. The strain grew optimally in 2–3% (w/v) NaCl, at pH 5.0–10.0 (optimally at pH 7.0) and between 0 and 30°C (optimum growth temperature 28°C). The strain exhibited a restricted substrate profile, with a preference for aliphatic hydrocarbons, that is consistent with its closest phylogenetic neighbour O. antarctica. Growth of the isolate at different temperatures affected the cellular fatty acid profile. 28°C cultured cells contained C_16:1ω7c and/or iso-C_15:0 2-OH (50.4%) and C_16:0 (19.2%) as the major fatty acids. However, the major fatty acids of the cells cultured at 4°C were C_16:1ω7c and/or C_16:1ω6c (40.2%), C_16:0 (17.2%) and C_17:1ω8c (10.1%). The G+C content of the genomic DNA was 42.7 mol%. Phylogeny based on 16S rRNA gene sequences together with data from DNA–DNA hybridization, phenotypic and chemotaxonomic characterization revealed that DFH11^T should be classified as a novel species of the genus Oleispira, for which the name Oleispira lenta sp. nov. is proposed, with the type strain DFH11^T (=NCIMB 14529^T = LMG 24829^T).     

Production of medium chain length polyhydroxyalkanoates by fed-batch culture of Pseudomonas oleovorans

Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHAs) from octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate in the culture broth was maintained below 4 g l^–1 by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above 7.1. The final cell concentrations of 63, 55 and 9.5 g l^–1, PHA contents of 62, 75 and 67% of dry cell wt, and productivities of 1, 0.63 and 0.16 g l^–1 h^–1 were obtained when the C/N ratios in the feed were 10, 20 and 100 g octanoic acid g^–1 ammonium nitrate, respectively.     

Cohnella plantaginis sp. nov., a novel nitrogen-fixing species isolated from plantain rhizosphere soil

A novel bacterium capable of fixing nitrogen was isolated from plantain rhizosphere soil in China. The isolate, designated YN-83^T, is Gram-positive, aerobic, motile and rod-shaped (0.4–0.6 μm × 1.9–2.6 μm). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain YN-83^T was a member of the genus Cohnella. High similarity of 16S rRNA gene sequence was found between YN-83^T and Cohnella ginsengisoli DSM18997^T (97.99%), whereas the similarity was below 96.0% between YN-83^T and the other Cohnella species. DNA–DNA relatedness between strain YN-83^T and C. ginsengisoli DSM18997^T was 27.4 ± 6.2%. The DNA G+C content of strain YN-83^T was 59.3 mol%. The predominant isoprenoid quinone was MK-7 and the major fatty acids were anteiso-C_15:0 (44.3%), iso-C_15:0 (11.3%), iso-C_16:0 (18.6%) and C_16:0 (7.7%). The polar lipids of strain YN-83^T consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, lyso- phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. On the basis of phenotypic and chemotaxonomic properties, 16S rRNA gene sequence, G+C content and DNA–DNA hybridization, strain YN-83^T represents a novel species of the genus Cohnella, for which the name Cohnella plantaginis sp. nov. (type strain YN-83^T = DSM 25424^T = CGMCC 1.12047^T) is proposed.     

Formation of Polyesters by Pseudomonas oleovorans: Effect of Substrates on Formation and Composition of Poly-(R)-3-Hydroxyalkanoates and Poly-(R)-3-Hydroxyalkenoates

Pseudomonas oleovorans grows on C₆ to C₁₂n-alkanes and 1-alkenes. These substrates are oxidized to the corresponding fatty acids, which are oxidized further via the β-oxidation pathway, yielding shorter fatty acids which have lost one or more C₂ units. P. oleovorans normally utilizes β-oxidation pathway intermediates for growth, but in this paper we show that the intermediate 3-hydroxy fatty acids can also be polymerized to intracellular poly-(R)-3-hydroxyalkanoates (PHAs) when the medium contains limiting amounts of essential elements, such as nitrogen. The monomer composition of these polyesters is a reflection of the substrates used for growth of P. oleovorans. The largest monomer found in PHAs always contained as many C atoms as did the n-alkane used as a substrate. Monomers which were shorter by one or more C₂ units were also observed. Thus, for C-even substrates, only C-even monomers were found, the smallest being (R)-3-hydroxyhexanoate. For C-odd substrates, only C-odd monomers were found, with (R)-3-hydroxyheptanoate as the smallest monomer. 1-Alkenes were also incorporated into PHAs, albeit less efficiently and with lower yields than n-alkanes. These PHAs contained both saturated and unsaturated monomers, apparently because the 1-alkene substrates could be oxidized to carboxylic acids at either the saturated or the unsaturated ends. Up to 55% of the PHA monomers contained terminal double bonds when P. oleovorans was grown on 1-alkenes. The degree of unsaturation of PHAs could be modulated by varying the ratio of alkenes to alkanes in the growth medium. Since 1-alkenes were also shortened before being polymerized, as was the case for n-alkanes, copolymers which varied with respect to both monomer chain length and the percentage of terminal double bonds were formed during nitrogen-limited growth of P. oleovorans on 1-alkenes. Such polymers are expected to be useful for future chemical modifications.     

<Emphasis Type="Italic">Photobacterium atrarenae</Emphasis> sp. nov. a Novel Bacterium Isolated from Sea Sand

The gram-reaction-negative, motile, facultatively anaerobic, catalase-positive, oxidase-positive bacterial strain M3-4^T was isolated from black sea sand and subjected to a taxonomic study. Cells of strain M3-4^T have monotrichous flagella, grow optimally at 37°C and at pH 7–8 in the presence of 1–4% (w/v) NaCl and hydrolyze casein, starch and l-tyrosine. According to phylogenetic analyses using 16S rRNA gene sequences, strain M3-4^T belongs to the genus Photobacterium and is most closely related to Photobacterium rosenbergii LMG 22223^T (97.4%) and P. gaetbulicola KCTC 22804^T (96.6%). The DNA–DNA relatedness value between M3-4^T and P. rosenbergii LMG 22223^T was 21.5%. The DNA G+C mol% of strain M3-4^T was 53.6. The major cellular fatty acid of strain M3-4^T was a summed feature 3 consisting of C_16:1 ω7c and/or iso-C_15:0 2-OH (35.0%), followed by C_16:0 (25.4%) and C_18:1ω7c (16.8%). These data suggest that strain M3-4^T represents a novel species in genus Photobacterium, for which the name P. atrarenae sp. nov. is proposed. The type strain is M3-4^T (= KCTC 23265^T = NCAIM B 02414^T).     

Taxonomic description of Pseudomonas rhizovicinus sp. nov., isolated from the rhizosphere of a desert shrub Haloxylon ammodendron

A Gram-negative aerobic bacterium, strain M30-35 ^T, was isolated from the rhizosphere of Haloxylon ammodendron in Tengger desert, Gansu province, northwest China. Our previous research indicated that strain M30-35 ^T can promote the growth of ryegrass (Lolium perenne L.). In this study, strain M30-35 ^T was subjected to a polyphasic taxonomic study. Phylogenetic analysis of the 16S rRNA gene and two other housekeeping genes (gyrB, rpoD) showed that strain M30-35 ^T is a member of Pseudomonas anguilliseptica group. The average nucleotide identity (ANI) scores for strains KMM 3042 ^T and FR1439^T were 76.5% and 83.7%, respectively, and DNA-DNA hybridization (DDH) were 21.6% and 26.6%, respectively, and the rates were less than the threshold range for species determination. The dominant cellular fatty acids of strain M30-35 ^T were C_16:0 (22.7%), summed feature 3 (C_16:1ω7c and/or C_16:1ω6c; 18.5%), summed feature 8 (C_18:1ω7c and/or C_18:1ω6c; 23.1%). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phospholipid and aminophospholipid and the predominant respiratory quinone was ubiquinone (Q9). On the basis of above data, it can be concluded that strain M30-35 ^T represents a novel species in the genus Pseudomonas, for which the name Pseudomonas rhizovicinus sp. nov. is proposed. The type strain is M30-35 ^T (=?MCCC 1K03247^T?=?KCTC 52664 ^T).

     

<Emphasis Type="Italic">Halomonas sediminis</Emphasis> sp. nov., a new halophilic bacterium isolated from salt-lake sediment in China

A novel Gram-negative, slightly halophilic, catalase- and oxidase-positive, obligately aerobic bacterium, strain YIM-C248^T, was isolated from a sediment sample collected from a salt-lake in the Qaidam Basin in Qinghai, north-west China. Cells were non-sporulating short rods, occurring singly or as doublets, motile with peritrichous flagella. Growth occurred with 1–15% (w/v) NaCl [optimum 2–4% (w/v) NaCl], at pH 6.0–10.0 (optimum pH 7.5) and at 4–35°C (optimum 25–30°C). The major cellular fatty acids were C_18:1 ω7c, C_12:0 3-OH, cyclo C_19:0 ω8c, C_16:0 and C_16:1. The predominant respiratory quinone was Q-9 and the genomic DNA G + C content was 58.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM-C248^T should be assigned to the genus Halomonas. The sequence similarities between the isolate and the type strains of members of the genus Halomonas were in the range of 92.5–97.5%. The combination of phylogenetic analysis, DNA–DNA hybridization data, phenotypic characteristics and chemotaxonomic differences supported the view that strain YIM-C248^T represents a new species of the genus Halomonas, for which the name Halomonas sediminis sp. nov. is proposed, with YIM-C248^T (=CCTCC AA 207031 = KCTC 22167) as the type strain. The GenBank/EMBL/DBBJ accession number for the 16S rRNA gene sequence of strain YIM-C248^T is EU135707.     

Vibrio tetraodonis subsp. pristinus subsp. nov., isolated from the coral Acropora cytherea at Palmyra Atoll,and creation and emended description of Vibrio tetraodonis subsp. tetraodonis subsp. nov

Strain OCN044^T was isolated from the homogenised tissue and mucus of an apparently healthy Acropora cytherea coral fragment collected from the western reef terrace of Palmyra Atoll in the Northern Line Islands and was taxonomically evaluated with a polyphasic approach. The morphological and chemotaxonomic properties are consistent with characteristics of the genus Vibrio: Gram-stain-negative rods, oxidase- and catalase-positive, and motile by means of a polar flagellum. Strain OCN044^T can be differentiated as a novel subspecies based on 21 differences among chemotaxonomic features (e.g., fatty acids percentages for C_12:0 and C_18:1 ω7c), enzymatic activities (e.g., DNase and cystine arylamidase), and carbon sources utilized (e.g., L-xylose and D-melezitose) from its nearest genetic relative. Phylogenetic analysis and genomic comparisons show close evolutionary relatedness to Vibrio tetraodonis A511^T but the overall genomic relatedness indices identify strain OCN044^T as a distinct subspecies. Based on a polyphasic characterisation, differences in genomic and taxonomic data, strain OCN044^T represents a novel subspecies of V. tetraodonis A511^T, for which the name Vibrio tetraodonis subsp. pristinus subsp. nov. is proposed. The type strain is OCN044^T (=?LMG 31895^T?=?DSM 111778^T).

     

Production of polyhydroxyalkanoic acids by Ralstonia eutropha and Pseudomonas oleovorans from an oil remaining from biotechnological rhamnose production

Screening experiments identified several bacteria which were able to use residual oil from biotechnological rhamnose production as a carbon source for growth. Ralstonia eutropha H16 and Pseudomonas oleovorans were able to use this waste material as the sole carbon source for growth and for the accumulation of polyhydroxyalkanoic acids (PHA). R. eutropha and P. oleovorans accumulated PHA amounting to 41.3% and 38.9%, respectively, of the cell dry mass, when these strains were cultivated in mineral salt medium with the oil from the rhamnose production as the sole carbon source. The accumulated PHA isolated from R. eutropha consisted of only 3-hydroxybutyric acid, whereas the PHA isolated from P. oleovorans consisted of 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxy decanoic acid, and 3-hydroxydodecanoic acid. The composition was confirmed by gas chromatography of the isolated polyesters. Batch and fed-batch cultivations in stirred-tank reactors were done. Received: 15 June 1999 / Received revision: 10 August 1999 / Accepted: 13 August 1999     

Kibdelosporangium phytohabitans sp. nov., a novel endophytic actinomycete isolated from oil-seed plant Jatropha curcas L. containing 1-aminocyclopropane-1-carboxylic acid deaminase

A novel actinomycete, designated strain KLBMP 1111^T, was isolated from the root of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Strain KLBMP 1111^T formed a distinct branch in the 16S rRNA gene phylogenetic tree together with the type strains in the genus Kibdelosporangium, with the highest similarity to Kibdelosporangium aridum subsp. aridum DSM 43828^T (98.8%), K. aridum subsp. largum DSM 44150^T (98.1%) and Kibdelosporangium philippinense DSM 44226^T (98.1%). The organism produced sporangium-like structures, the typical morphological characteristic of the genus Kibdelosporangium. The chemotaxonomic properties of this strain were also consistent with those of the genus Kibdelosporangium: the peptidoglycan contained meso-diaminopimelic acid; the predominant menaquinone was MK-9(H₄); phospholipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol and an unknown phospholipid; iso-C_16:0, C_16:0, anteiso-C_15:0 and iso-C_15:0 as the predominant cellular fatty acids and the G+C content was 67.2 mol%. DNA–DNA hybridization values between strain KLBMP 1111^T and the three Kibdelosporangium species were less than 50%. This strain had the ability to produce a siderophore, utilized 1-aminocyclopropane-1-carboxylic acid (ACC) as sole source of nitrogen and possessed ACC deaminase enzyme. Based on genotypic and phenotypic data, strain KLBMP 1111^T represents a novel species in the genus Kibdelosporangium. We propose the name Kibdelosporangium phytohabitans sp. nov. for this species. The type strain is the strain KLBMP 1111^T (=KCTC 19775^T = CCTCC AA 2010001^T).     

Characterization of <Emphasis Type="Italic">Deinococcus sahariens</Emphasis> sp. nov., a radiation-resistant bacterium isolated from a Saharan hot spring

An ultraviolet-radiation-resistant, Gram-positive, orange-pigmented, thermophilic and strictly aerobic cocci was isolated from Saharan water hot spring in Tunisia. The newly isolated bacterium, designated HAN-23^T, was identified based on polyphasic taxonomy including genotypic, phenotypic and chemotaxonomic characterization. Phylogenetic analysis based on 16S rRNA gene sequences placed this strain within Deinococcus genus. However, strain HAN-23^T is different from recognized species of the genus Deinococcus, showing less than 94.0% similarity values to its closest relatives. The predominant cellular fatty acids determined by gas chromatography were iso-C_15:0, iso-C_17:0 and iso C_17:1 ω9c. The major respiratory quinone was MK-8. The DNA G + C content was 66.9 mol%. DNA–DNA hybridization measurements revealed low DNA relatedness (6%) between the novel isolate and its closest neighbor, the type strain Deinococcus geothermalis DSM 11300. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain HAN-23^T represents a novel species of the genus Deinococcus, for which the name Deinococcus sahariens sp. nov. is proposed, the type strain being HAN-23^T (=DSM 18496^T; LMG 23756^T).     

Streptomyces phytohabitans sp. nov., a novel endophytic actinomycete isolated from medicinal plant Curcuma phaeocaulis

A novel actinomycete, designated strain KLBMP 4601^T, was isolated from the root of the medicinal plant Curcuma phaeocaulis collected from Sichuan Province, south-west China. The strain produced extensively branched substrate and aerial hyphae that carried straight to flexuous spore chains. Chemotaxonomic properties of this strain were consistent with those of members of the genus Streptomyces. The cell wall of strain KLBMP 4601^T contained ll-diaminopimelic acid as the characteristic diamino acid. The major menaquinone was MK-9(H₄), with minor amounts of MK-9(H₆), MK-9(H₈) and MK-10(H₂). The major fatty acids were C_16:0, iso-C_16:0, C_18:1ω9c and C_16:1, iso G. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain KLBMP 4601^T belongs to the genus Streptomyces and is most closely related to Streptomyces armeniacus JCM 3070^T (97.9 %), Streptomyces pharmamarensis PM267^T (97.6 %) and Streptomyces artemisiae YIM 63135^T (97.5 %). The 16S rRNA gene sequence similarity between strain KLBMP 4601^T and other members of this genus were lower than 97.5 %. DNA–DNA hybridization studies of strain KLBMP 4601^T with the three closest species showed relatedness values of 36.3 ± 4.2 %, 27.3 ± 0.6 %, and 30.9 ± 2.5 %, respectively. On the basis of chemotaxonomic, phenotypic and genotypic characteristics, it is evident that strain KLBMP 4601^T represents a novel species of the genus Streptomyces, for which the name Streptomyces phytohabitans sp. nov. is proposed. The type strain is KLBMP 4601^T (=KCTC 19892^T = NBRC 108772^T).     

Pseudomonas petrae sp. nov. isolated from regolith samples in Antarctica

A polyphasic taxonomic approach was used to characterize the four strains P2653^T, P2652, P2498, and P2647, isolated from Antarctic regolith samples. Initial genotype screening performed by PCR fingerprinting based on repetitive sequences showed that the isolates studied formed a coherent cluster separated from the other Pseudomonas species. Identification results based on 16S rRNA gene sequences showed the highest sequence similarity with Pseudomonas graminis (99.7%), which was confirmed by multilocus sequence analysis using the rpoB, rpoD, and gyrB genes. Genome sequence comparison of P2653^T with the most related P. graminis type strain DSM 11363^T revealed an average nucleotide identity of 92.1% and a digital DNA-DNA hybridization value of 46.6%. The major fatty acids for all Antarctic strains were C_16:0, Summed Feature 3 (C_16:1 ω7c/C_16:1 ω6c) and Summed Feature 8 (C_18:1 ω7c/C_18:1 ω6c). The predominant respiratory quinone was Q-9, and the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. The regolith strains could be differentiated from related species by the absence of arginine dihydrolase, ornithine and lysine decarboxylase and by negative tyrosine hydrolysis. The results of this polyphasic study allowed the genotypic and phenotypic differentiation of four analysed strains from the closest related species, which confirmed that the strains represent a novel species within the genus Pseudomonas, for which the name Pseudomonas petrae sp. nov. is proposed with P2653^T (CCM 8850^T = DSM 112068^T = LMG 30619^T) as the type strain.