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Int J Syst Evol Microbiol 56 (2006), 765-770; DOI  10.1099/ijs.0.63954-0
© 2006 International Union of Microbiological Societies

Halovivax asiaticus gen. nov., sp. nov., a novel extremely halophilic archaeon isolated from Inner Mongolia, China

A. M. Castillo1, M. C. Gutiérrez1, M. Kamekura2, Y. Ma3, D. A. Cowan4, B. E. Jones5, W. D. Grant6 and A. Ventosa1

1 Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
2 Noda Institute for Scientific Research, 399 Noda, Noda-shi, Chiba-ken 278-0037, Japan
3 State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100080 Beijing, China
4 Department of Biotechnology, University of the Western Cape, Bellville 7535, Cape Town, South Africa
5 Genencor International BV, Archimedesweg 30, 2333 CN Leiden, The Netherlands
6 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK

Correspondence
A. Ventosa
ventosa{at}us.es


    ABSTRACT
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 ABSTRACT
 MAIN TEXT
 REFERENCES
 
Strain EJ-46T, a novel pleomorphic, aerobic, extremely halophilic member of the Archaea was isolated from sediment of the saline Lake Ejinor, in Inner Mongolia, China. This organism was neutrophilic and required at least 15 % (2·5 M) NaCl for growth. MgCl2 was not required. The isolate was able to grow at pH 6·0–9·0. Optimum growth occurred in media containing 20 % (3·4 M) NaCl at pH 7·0–7·5. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, derived from both C20C20 and C20C25 glycerol diethers. Four glycolipids were detected, one of which may be novel. The DNA G+C content was 60·3 mol%. 16S rRNA gene analysis revealed that strain EJ-46T was a member of the phylogenetic group defined by the family Halobacteriaceae, and the highest 16S rRNA gene similarity values of 94·9 and 94·8 % were obtained with the haloalkaliphilic species of the genus Natronococcus, Natronococcus occultus and Natronococcus amylolyticus, respectively. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the novel isolate should be classified as representing a new genus and species, for which the name Halovivax asiaticus gen. nov., sp. nov. is proposed. The type strain is EJ-46T (=CGMCC 1.4248T=CECT 7098T).


Published online ahead of print on 9 December 2005 as DOI 10.1099/ijs.0.63954-0.

The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain EJ-46T is AM039978.

TLC of polar lipids extracted from Halovivax asiaticus gen. nov., sp. nov. and some other haloarchaea are available as supplementary material in IJSEM Online.


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The extremely halophilic, aerobic members of the Archaea are classified within the family Halobacteriaceae, order Halobacteriales, with 20 currently recognized genera: Halalkalicoccus (Xue et al., 2005Go), Haloarcula (Torreblanca et al., 1986Go), Halobacterium (Grant, 2001aGo), Halobaculum (Oren et al., 1995Go), Halobiforma (Hezayen et al., 2002Go), Halococcus (Grant, 2001bGo), Haloferax (Torreblanca et al., 1986Go), Halogeometricum (Montalvo-Rodríguez et al., 1998Go), Halomicrobium (Oren et al., 2002Go), Halorhabdus (Wainø et al., 2000Go), Halorubrum (McGenity & Grant, 1995Go), Halosimplex (Vreeland et al., 2002Go), Haloterrigena (Ventosa et al., 1999Go), Natrialba (Kamekura & Dyall-Smith, 1995Go), Natrinema (McGenity et al., 1998Go), Natronobacterium (Tindall et al., 1984Go), Natronococcus (Tindall et al., 1984Go), Natronolimnobius (Itoh et al., 2005Go), Natronomonas (Kamekura et al., 1997Go) and Natronorubrum (Xu et al., 1999Go). The current taxonomic classification of this archaeal group is based largely on 16S rRNA gene sequence comparison and chemotaxonomic criteria, particularly polar lipid composition (Grant et al., 2001Go).

Members of the Halobacteriaceae are usually pink- to red-pigmented because of the presence of carotenoids (Kamekura & Dyall-Smith, 1995Go; Hezayen et al., 2001Go; Grant et al., 2001Go). They have been isolated from various hypersaline environments, such as saline lakes (e.g. Franzmann et al., 1988Go; Oren et al., 1995Go), soda lakes (e.g. Soliman & Trüper, 1982Go; Tindall et al., 1984Go), salterns (e.g. Nuttall & Dyall-Smith, 1993Go; Juez et al., 1986Go; Ihara et al., 1997Go), saline soils (e.g. Kobayashi et al., 1992Go) or salt mines (e.g. Denner et al., 1994Go; Norton et al., 1993Go). The haloarchaea are the most halophilic organisms known and are dominant in hypersaline environments in which the salt concentration exceeds 25 % (w/v) (Rodriguez-Valera et al., 1981Go). They often appear at such high density that they impart a typical red colour to the hypersaline brines.

Hypersaline environments are commonly found in China. In addition to many coastal salterns, a number of salt lakes, soda lakes and salt-rich deserts are located in various geographical areas of China, e.g. Xinjiang, Inner Mongolia and Tibet Autonomous Regions. A number of new members of the Halobacteriaceae have been isolated from these saline environments (Xu et al., 1999Go, 2001Go; Xin et al., 2000Go, 2001Go; Fan et al., 2004Go; Feng et al., 2004Go, 2005Go). In this paper, we report the isolation of strain EJ-46T from Lake Ejinor in Inner Mongolia, China. The complete 16S rRNA gene sequence of strain EJ-46T as well as the polar lipid composition were analysed and the phenotypic characteristics were compared with those of other extremely halophilic archaea to determine the taxonomic position of strain EJ-46T. On the basis of these and other taxonomic data, we found that strain EJ-46T was not identical to any of the present haloarchaeal taxa and was sufficiently different from them to justify its classification as representing a novel species within a new genus.

Strain EJ-46T was isolated from a sediment sample from the saline Lake Ejinor (45° 14' N 116° 32' E) in Inner Mongolia, China, by enrichment in liquid medium and subsequent plating of the enriched culture until purity was obtained on the same medium but with agar added. The medium contained (l–1): NaCl, 195 g; MgCl2.6H2O, 32·5 g; MgSO4.7H2O, 50·8 g; CaCl2, 0·8 g; KCl, 5 g; NaHCO3, 0·16 g; NaBr, 0·6 g; and yeast extract 5 g. The pH was adjusted to 7·5 with 1 M NaOH. The water of the lake had a salinity of 338·5 g l–1 and a pH of 7·4. Strain EJ-46T grew at a temperature range of 25–45 °C (optimum 37 °C) and a pH range of 6·0–9·0 (optimum 7·0–7·5). Routine cultivation was conducted at 37 °C and pH 7·5. The requirements for NaCl and MgCl2 for growth were determined in media containing 0·9–5·2 M NaCl or 0–0·5 M MgCl2. Strain EJ-46T was capable of growing in a wide range of NaCl concentrations, ranging from 15 (2·5 M) to 25 % (4·3 M). It grew optimally in the presence of 20 % (3·4 M) NaCl, as has been shown for most extremely halophilic archaea. MgCl2 was not required for growth.

Phenotypic tests were performed according to the proposed minimal standards for the description of new taxa in the order Halobacteriales (Oren et al., 1997Go). Tests for catalase and oxidase activities and hydrolysis of starch and Tween 80 were performed as described previously (Gonzalez et al., 1978Go). Nitrate reduction, H2S formation, indole production and the utilization of sugars, alcohols, amino acids and organic acids were assessed as described by Oren et al. (1997)Go. The catalase reaction was positive. Oxidase activity was weakly positive. Voges–Proskauer, methyl red, nitrate reduction, indole production from tryptophan and Simmons citrate tests were negative. Casein, gelatin and Tween 80 were hydrolysed. Starch, DNA and aesculin were not hydrolysed. The susceptibility to antibiotics was determined on agar medium plates by using antibiotic discs with the following concentrations: ampicillin (10 µg), bacitracin (10 U), chloramphenicol (30 µg), erythromycin (15 µg), gentamicin (10 µg), nalidixic acid (30 µg), neomycin (10 µg), novobiocin (30 µg), penicillin G (10 U), rifampicin (30 µg), streptomycin (10 µg) and tetracycline (30 µg). Isolation medium in which yeast extract was added at 0·05 % (w/v), supplemented with 1 % (w/v) of the tested substrate, was used to determine the utilization of various organic substrates as carbon and energy or as carbon, nitrogen and energy sources (Torreblanca et al., 1986Go). The results of antibiotic susceptibility tests and utilization of various substrates are included in the species description. The formation of acid from various sugars was tested in medium containing 0·05 % (w/v) yeast extract, supplemented with 1 % (w/v) of the sugar tested (sterilized separately). Acid was produced oxidatively from D-xylose but not from D-arabinose, D-fructose, D-galactose, D-glucose, lactose, maltose, D-mannose, sucrose, trehalose or glycerol.

Cell morphology and motility were examined using a Olympus BX41 microscope equipped with phase-contrast optics. For photography, drops of exponentially growing liquid cultures were mixed on a microscope slide with an equal volume of melted 1 % agarose containing 20 % (w/v) NaCl, and then covered with a coverslip. Cells were non-motile and pleomorphic, from rods to triangles or squares or disk-shaped (Fig. 1Go). Colony morphology was observed on agar medium under optimal growth conditions after incubation at 37 °C for 10 days. Colonies of strain EJ-46T formed on agar plates were circular, elevated, entire, small, opaque, glossy and pale-pink pigmented.


Figure 1
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Fig. 1. Phase-contrast micrograph of strain EJ-46T grown in liquid medium under optimum conditions. Bar, 15 µm.

 
Polar lipids were extracted with chloroform/methanol as described previously (Kamekura, 1993Go). TLC was done using Merck HPTLC plates silica gel 60 (art. 5641) in the solvent system chloroform/methanol/acetic acid/water (85 : 22·5 : 10 : 4, by vol.). Glycolipids were detected as purple spots by spraying 0·5 % {alpha}-naphthol in methanol/water (1 : 1) and then with sulphuric acid/ethanol (1 : 1), followed by heating at 160 °C. Two phospholipids, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol were detected as brown spots after prolonged heating. TLC of the polar lipids suggested that strain EJ-46T contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester derived from C20C20 and C20C25 glycerol diethers, as shown from the two spots (Xin et al., 2000Go). Four glycolipids were detected, three of which, with the exception of the fast-moving one, showed the same mobilities as those detected in Natrinema pellirubrum JCM 10476T (Xin et al., 2000Go). The slowest-moving glycolipid possessed an Rf that was smaller than that of sulphated tetraglycosyl archaeol, which was identified in Halobacterium salinarum (Kamekura, 1993Go). The glycolipid detected between phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester was not observed in Natrinema pellirubrum (see Supplementary Figs S1 and S2 in IJSEM Online).

Chromosomal DNA of strain EJ-46T was isolated and purified according to methods described by Wilson (1987)Go and Marmur (1961)Go. The G+C content of genomic DNA was determined from the mid-point (Tm) of the thermal denaturation profile (Marmur & Doty, 1962Go) using the equation of Owen & Hill (1979)Go. The DNA G+C content of strain EJ-46T was 60·3 mol%. The 16S rRNA gene of strain EJ-46T was amplified by PCR using three universal primers as described by López-Garcia et al. (2001)Go and Arahal et al. (1996)Go and almost-complete nucleotide sequences (approx. 1400 bp) were determined. The ARB software package (Ludwig et al., 2004Go) was used for the 16S rRNA gene sequence analysis. Base-frequency filters were applied in the sequence comparison analysis and the effects on the results were evaluated. 16S rRNA gene phylogenetic analysis performed based on the neighbour-joining method (Saitou & Nei, 1987Go) showed the position of strain EJ-46T (Fig. 2Go). The new isolate constituted a separate phylogenetic branch within the Halobacteriaceae. The 16S rRNA gene similarity between EJ-46T and its closest phylogenetic relatives was 94·9 and 94·8 % with Natronococcus occultus and Natronococcus amylolyticus, respectively. Similar topologies were obtained when other treeing methods (maximum-parsimony and maximum-likelihood) were used. These two species of the genus Natronococcus are haloalkaliphilic cocci, with optimum growth at alkaline pH values, in contrast to EJ-46T, which is a neutrophilic rod, growing optimally at pH 7·0–7·5. In addition, alignment of the 16S rRNA gene sequence with all published sequences of haloarchaea clearly showed that strain EJ-46T does not belong to the genus Natronococcus, as it does not share any of the signature bases defined for that genus (Kamekura et al., 2004Go).


Figure 2
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Fig. 2. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showing the positions of strain EJ-46T and some other related haloarchaeal species. GenBank accession numbers are shown in parentheses. Bar, 1 % sequence divergence.

 
The phenotypic and chemotaxonomic features and the phylogenetic data based on the 16S rRNA sequence comparison clearly support the placement of strain EJ-46T in a new genus and species within the haloarchaea, for which we propose the name Halovivax asiaticus gen. nov., sp. nov. The characteristics that differentiate the new genus from other related haloarchaeal genera are shown in Table 1Go.


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Table 1. Characteristics that distinguish Halovivax asiaticus gen. nov., sp. nov. from other related haloarchaeal genera

Genera: 1, Halovivax; 2, Halorubrum; 3, Haloarcula; 4, Natronobacterium; 5, Natronococcus; 6, Natrialba; 7, Natrinema. Data from Grant et al. (2001)Go, Tindall (1992)Go, Oren (2000)Go and this study. +, Positive; –, negative; ND, not determined; V, variable.

 
Description of Halovivax gen. nov.
Halovivax (Ha.lo.vi'vax. Gr. n. hals, halos salt; L. adj. vivax long-lived, tenacious of life; N.L. masc. n. Halovivax long-living halophile).

Gram-negative. Cells are extremely pleomorphic, although most are rod-shaped. Colonies are pale-pink pigmented. Strictly aerobic; oxygen is used as the final electron acceptor. Growth occurs at pH 6·0–9·0, 25–45 °C and in 15–25 % (2·5–4·3 M) NaCl. Optimum growth occurs at pH 7·0–7·5, 37 °C and 20 % (3·4 M) NaCl. The DNA G+C content of the only species in the genus is 60·3 mol% (Tm method). Polar lipids include phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, two major and one minor glycolipids similar to those of Natrinema pellirubrum and a unidentified glycolipid. Isolated from salt lakes. Phylogenetically affiliated to the Halobacteriaceae. The type species of the genus is Halovivax asiaticus.

Description of Halovivax asiaticus sp. nov.
Halovivax asiaticus (a.si.a'ti.cus. L. masc. adj. asiaticus pertaining to Asia, where the type strain was isolated).

Exhibits the following properties in addition to those given in the genus description. Cells are 0·4–0·5x4·0–5·0 µm (Fig. 1Go). Colonies are circular and 1–2 mm in diameter after incubation for 10 days at 37 °C. Extremely halophilic and the cells lyse in water. MgCl2 is not required. Growth does not occur above 50 °C. Amino acids are not required for growth. Catalase-positive and weakly positive for oxidase. Production of indole and methyl red, Voges–Proskauer and Simmons citrate tests are negative. H2S is produced from cysteine. Acid is produced from xylose. Does not produce arginine dihydrolase, lysine decarboxylase or ornithine decarboxylase. Produces urease. Anaerobic growth with nitrate or L-arginine does not occur. Starch, aesculin, phosphatase and DNase are not hydrolysed. Gelatin, Tween 80 and casein are hydrolysed. Nitrate is not reduced to nitrite. The following substrates are utilized for growth: lactose, raffinose, xylose, propionate, glutamate, trehalose and acetate. No growth occurs on mannitol, D-arabinose, D-galactose, maltose, sucrose, glycerol, sorbitol, fructose, D-glucose, ribose, starch, succinate, malate or fumarate. Sensitive to bacitracin and novobiocin. Resistant to ampicillin, chloramphenicol, erythromycin, gentamicin, nalidixic acid, neomycin, penicillin G, rifampicin, streptomycin and tetracycline. The G+C content of the DNA of the type and only strain is 60·3 mol%.

The type strain, EJ-46T (=CGMCC 1.4248T=CECT 7098T), was isolated from the saline Lake Ejinor in Inner Mongolia, China.


    ACKNOWLEDGEMENTS
 
This study was supported by grants from the Quality of Life and Management of Living Resources Programme of the European Commission (Project ‘Multigenome Access Technology for Industrial Catalysts’, QLK3-CT-2002-01972), Spanish Ministerio de Educacion y Ciencia (BMC2003-01344 and BIO2002-11399-E) and from the Junta de Andalucia.


    REFERENCES
 TOP
 ABSTRACT
 MAIN TEXT
 REFERENCES
 
Arahal, D. R., Dewhirst, F. E., Paster, B. J., Volcani, B. E. & Ventosa, A. (1996). Phylogenetic analyses of some extremely halophilic archaea isolated from Dead Sea water, determined on the basis of their 16S rRNA sequences. Appl Environ Microbiol 62, 3779–3786.[Abstract]

Denner, E. B. M., McGenity, T. J., Busse, H.-J., Grant, W. D., Wanner, G. & Stan-Lotter, H. (1994). Halococcus salifodinae sp. nov., an archaeal isolate from an Austrian salt mine. Int J Syst Bacteriol 44, 774–780.[Abstract/Free Full Text]

Fan, H., Xue, Y., Ma, Y., Ventosa, A. & Grant, W. D. (2004). Halorubrum tibetense sp. nov., a novel haloalkaliphilic archaeon from Lake Zabuye in Tibet, China. Int J Syst Evol Microbiol 54, 1213–1216.[Abstract/Free Full Text]

Feng, J., Zhou, P.-J. & Liu, S.-J. (2004). Halorubrum xinjiangense sp. nov., a novel halophile isolated from saline lakes in China. Int J Syst Evol Microbiol 54, 1789–1791.[Abstract/Free Full Text]

Feng, J., Zhou, P., Zhou, Y.-G., Liu, S.-J. & Warren-Rhodes, K. (2005). Halorubrum alkaliphilum sp. nov., a novel haloalkaliphile isolated from a soda lake in Xinjiang, China. Int J Syst Evol Microbiol 55, 149–152.[Abstract/Free Full Text]

Franzmann, P. D., Stackebrandt, E., Sanderson, K., Volkman, J. K., Cameron, D. E., Stevenson, P. L., McMeekin, T. A. & Burton, H. R. (1988). Halobacterium lacusprofundi sp. nov., a halophilic bacterium isolated from Deep Lake, Antarctica. Syst Appl Microbiol 11, 20–27.

Gonzalez, C., Gutierrez, C. & Ramirez, C. (1978). Halobacterium vallismortis sp. nov. An amylolytic and carbohydrate-metabolizing, extremely halophilic bacterium. Can J Microbiol 24, 710–715.[Medline]

Grant, W. D. (2001a). Genus I. Halobacterium Elazari-Volcani 1957, 207,AL emend. Larsen and Grant 1989, 2222. In Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 1, pp. 301–305. Edited by D. R. Boone, R. W. Castenholz & G. M. Garrity. New York: Springer.

Grant, W. D. (2001b). Genus IV. Halococcus Schoop 1935a, 817AL. In Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 1, pp. 311–314. Edited by D. R. Boone, R. W. Castenholz & G. M. Garrity. New York: Springer.

Grant, W. D., Kamekura, M., McGenity, T. J. & Ventosa, A. (2001). Order I. Halobacteriales Grant and Larsen 1989b, 495VP (Effective publication: Grant and Larsen 1989a, 2216). In Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 1, pp. 294–334. Edited by D. R. Boone, R. W. Castenholz & G. M. Garrity. New York: Springer.

Hezayen, F. F., Rehm, B. H. A., Tindall, B. J. & Steinbüchel, A. (2001). Transfer of Natrialba asiatica B1T to Natrialba taiwanensis sp. nov. and description of Natrialba aegyptiaca sp. nov., a novel extremely halophilic, aerobic, non-pigmented member of the Archaea from Egypt that produces extracellular poly(glutamic acid). Int J Syst Evol Microbiol 51, 1133–1142.[Abstract]

Hezayen, F. F., Tindall, B. J., Steinbüchel, A. & Rehm, B. H. A. (2002). Characterization of a novel halophilic archaeon, Halobiforma haloterrestris gen. nov., sp. nov., and transfer of Natronobacterium nitratireducens to Halobiforma nitratireducens comb. nov. Int J Syst Evol Microbiol 52, 2271–2280.[Abstract]

Ihara, K., Watanabe, S. & Tamura, T. (1997). Haloarcula argentinensis sp. nov. and Haloarcula mukohataei sp. nov., two new extremely halophilic archaea collected in Argentina. Int J Syst Bacteriol 47, 73–77.[Abstract/Free Full Text]

Itoh, T., Yamaguchi, T., Zhou, P. & Takashina, T. (2005). Natronolimnobius baerhuensis gen. nov., sp. nov. and Natronolimnobius innermongolicus sp. nov., novel haloalkaliphilic archaea isolated from soda lakes in Inner Mongolia, China. Extremophiles 9, 111–116.[CrossRef][Medline]

Juez, G., Rodriguez-Valera, F., Ventosa, A. & Kushner, D. J. (1986). Haloarcula hispanica spec. nov. and Haloferax gibbonsii spec. nov., two new species of extremely halophilic archaebacteria. Syst Appl Microbiol 8, 75–79.

Kamekura, M. (1993). Lipids of extreme halophiles. In The Biology of Halophilic Bacteria, pp. 135–161. Edited by R. H. Vreeland & L. I. Hochstein. Boca Raton, FL: CRC Press.

Kamekura, M. & Dyall-Smith, M. L. (1995). Taxonomy of the family Halobacteriaceae and the description of two genera Halorubrubacterium and Natrialba. J Gen Appl Microbiol 41, 333–350.

Kamekura, M., Dyall-Smith, M. L., Upasani, V., Ventosa, A. & Kates, M. (1997). Diversity of alkaliphilic halobacteria: proposals for transfer of Natronobacterium vacuolatum, Natronobacterium magadii, and Natronobacterium pharaonis to Halorubrum, Natrialba, and Natronomonas gen. nov., respectively, as Halorubrum vacuolatum comb. nov., Natrialba magadii comb. nov., and Natronomonas pharaonis comb. nov., respectively. Int J Syst Bacteriol 47, 853–857.[Abstract/Free Full Text]

Kamekura, M., Mizuki, T., Usami, R., Yoshida, Y., Horikoshi, K. & Vreeland, R. H. (2004). The potential use of signature bases from 16S rRNA gene sequences to aid the assignment of microbial strains to genera of halobacteria. In Halophilic Microorganisms, pp. 77–87. Edited by A. Ventosa. Heidelberg: Springer.

Kobayashi, T., Kanai, H., Hayashi, T., Akiba, T., Akaboshi, R. & Horikoshi, K. (1992). Haloalkaliphilic maltotriose-forming {alpha}-amylase from the archaebacterium Natronococcus sp. strain Ah-6. J Bacteriol 174, 3439–3444.[Abstract/Free Full Text]

López-Garcia, P., Moreira, D., López-López, A. & Rodríguez-Valera, F. (2001). A novel haloarchaeal-related lineage is widely distributed in deep oceanic regions. Environ Microbiol 3, 72–78.[CrossRef][Medline]

Ludwig, W., Strunk, O., Westram, R. & 29 other authors (2004). ARB: a software environment for sequence data. Nucleic Acids Res 32, 1363–1371.[Abstract/Free Full Text]

Marmur, J. (1961). A procedure for the isolation of deoxyribonucleic acid from microorganisms. J Mol Biol 3, 208–218.

Marmur, J. & Doty, P. (1962). Determination of the base composition of deoxyribonucleic acid from its thermal denaturation temperature. J Mol Biol 5, 109–118.[Medline]

McGenity, T. J. & Grant, W. D. (1995). Transfer of Halobacterium saccharovorum, Halobacterium sodomense, Halobacterium trapanicum NRC 34021 and Halobacterium lacusprofundi to the genus Halorubrum gen. nov., as Halorubrum saccharovorum comb. nov., Halorubrum sodomense comb. nov., Halorubrum trapanicum comb. nov., and Halorubrum lacusprofundi comb. nov. Syst Appl Microbiol 18, 237–243.

McGenity, T. J., Gemmell, R. T. & Grant, W. D. (1998). Proposal of a new halobacterial genus Natrinema gen. nov., with two species Natrinema pellirubrum nom. nov. and Natrinema pallidum nom. nov. Int J Syst Bacteriol 48, 1187–1196.[Abstract/Free Full Text]

Montalvo-Rodríguez, R., Vreeland, R. H., Oren, A., Kessel, M., Betancourt, C. & López-Garriga, J. (1998). Halogeometricum borinquense gen. nov., sp. nov., a novel halophilic archaeon from Puerto Rico. Int J Syst Bacteriol 48, 1305–1312.[Abstract/Free Full Text]

Norton, C. F., McGenity, T. J. & Grant, W. D. (1993). Archaeal halophiles (halobacteria) from two British salt mines. J Gen Microbiol 139, 1077–1081.

Nuttall, S. D. & Dyall-Smith, M. L. (1993). Ch2, a novel halophilic archaeon from an Australian solar saltern. Int J Syst Bacteriol 43, 729–734.[Abstract/Free Full Text]

Oren, A. (2000). The order Halobacteriales. In The Prokaryotes: An Evolving Electronic Resource for the Microbiological Community, 3rd edn, release 3·2. Edited by M. Dworkin, S. Falkow, E. Rosenberg, K.-H. Schleifer & E. Stackebrandt. New York: Springer. http://141.150.157.117 : 8080/prokPUB/index.htm

Oren, A., Gurevich, P., Gemmell, R. T. & Teske, A. (1995). Halobaculum gomorrense gen. nov., sp. nov., a novel extremely halophilic archaeon from the Dead Sea. Int J Syst Bacteriol 45, 747–754.[Abstract/Free Full Text]

Oren, A., Ventosa, A. & Grant, W. D. (1997). Proposed minimal standards for description of new taxa in the order Halobacteriales. Int J Syst Bacteriol 47, 233–238.[Abstract/Free Full Text]

Oren, A., Elevi, R., Watanabe, S., Ihara, K. & Corcelli, A. (2002). Halomicrobium mukohataei gen. nov., comb. nov., and emended description of Halomicrobium mukohataei. Int J Syst Evol Microbiol 52, 1831–1835.[Abstract]

Owen, R. J. & Hill, L. R. (1979). The estimation of base compositions, base pairing and genome size of bacterial deoxyribonucleic acids. In Identification Methods for Microbiologists, 2nd edn, pp. 217–296. Edited by F. A. Skinner & D. W. Lovelock. London: Academic Press.

Rodriguez-Valera, F., Ruiz-Berraquero, F. & Ramos-Cormenzana, A. (1981). Characteristics of the heterotrophic bacterial populations in hypersaline environments of different salt concentrations. Microb Ecol 7, 235–243.[CrossRef]

Saitou, N. & Nei, M. (1987). The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4, 406–425.[Abstract]

Soliman, G. S. H. & Trüper, H. G. (1982). Halobacterium pharaonis sp. nov., a new extremely haloalkaliphilic archaebacterium with low magnesium requirement. Zentralbl Bakteriol Hyg I Abt Orig C 3, 318–329.

Tindall, B. J. (1992). The family Halobacteriaceae. In The Prokaryotes. A Handbook of Bacteria: Ecophysiology, Isolation, Identification, Applications, 2nd edn, vol. 1, pp. 768–808. Edited by A. Balows, H. G. Trüper, M. Dworkin, W. Harder & K.-H. Schleifer. New York: Springer.

Tindall, B. J., Ross, H. N. M. & Grant, W. D. (1984). Natronobacterium gen. nov. and Natronococcus gen. nov., two new genera of haloalkaliphilic archaebacteria. Syst Appl Microbiol 5, 41–57.

Torreblanca, M., Rodriguez-Valera, F., Juez, G., Ventosa, A., Kamekura, M. & Kates, M. (1986). Classification of non-alkaliphilic halobacteria based on numerical taxonomy and polar lipid composition and description of Haloarcula gen. nov. and Haloferax gen. nov. Syst Appl Microbiol 8, 89–99.

Ventosa, A., Gutiérrez, M. C., Kamekura, M. & Dyall-Smith, M. L. (1999). Proposal to transfer Halococcus turkmenicus, Halobacterium trapanicum JCM 9743 and strain GSL-11 to Haloterrigena turkmenica gen. nov., comb. nov. Int J Syst Bacteriol 49, 131–136.[Abstract/Free Full Text]

Vreeland, R. H., Straight, S., Krammes, J., Dougherty, K., Rosenzweig, W. D. & Kamekura, M. (2002). Halosimplex carlsbadense gen. nov., sp. nov., a unique halophilic archaeon, with three 16S rRNA genes, that grows only in defined medium with glycerol and acetate or pyruvate. Extremophiles 6, 445–452.[CrossRef][Medline]

Wainø, M., Tindall, B. J. & Ingvorsen, K. (2000). Halorhabdus utahensis gen. nov., sp. nov., an aerobic, extremely halophilic member of the Archaea from Great Salt Lake, Utah. Int J Syst Evol Microbiol 50, 183–190.[Abstract]

Wilson, K. (1987). Preparation of genomic DNA from bacteria. In Current Protocols in Molecular Biology, pp. 2.4.1–2.4.2. Edited by F. M. Ausubel, R. Bent, R. E. Kingston, D. D. Moore, J. G. Seidman, J. A. Smith & K. Struhl. New York: Wiley.

Xin, H., Itoh, T., Zhou, P., Suzuki, K., Kamekura, M. & Nakase, Y. (2000). Natrinema versiforme sp. nov., an extremely halophilic archeon from Aibi salt lake, Xinjiang, China. Int J Syst Evol Microbiol 50, 1297–1303.[Abstract]

Xin, H., Itoh, T., Zhou, P., Suzuki, K. & Nakase, Y. (2001). Natronobacterium nitratireducens sp. nov., a haloalkaliphilic archaeon isolated from a soda lake in China. Int J Syst Evol Microbiol 51, 1825–1829.[Abstract]

Xu, Y., Zhou, P. & Tian, X. (1999). Characterization of two novel haloalkaliphilic archaea Natronorubrum bangense gen. nov., sp. nov. and Natronorubrum tibetense gen. nov., sp. nov. Int J Syst Bacteriol 49, 261–266.[Abstract/Free Full Text]

Xu, Y., Wang, Z., Xue, Y., Zhou, P., Ma, Y., Ventosa, A. & Grant, W. D. (2001). Natrialba hulunbeirensis sp. nov. and Natrialba chahannaoensis sp. nov., novel haloalkaliphilic archaea from soda lakes in Inner Mongolia Autonomous Region, China. Int J Syst Evol Microbiol 51, 1693–1698.[Abstract]

Xue, Y., Fan, H., Ventosa, A., Grant, W. D., Jones, B. E., Cowan, D. A. & Ma, Y. (2005). Halalkalicoccus tibetensis gen. nov., sp. nov., representing a novel genus of haloalkaliphilic archaea. Int J Syst Evol Microbiol 55, 2501–2505.[Abstract/Free Full Text]




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