|
|
||||||||
1 Extremobiosphere Research Center, Japan Agency for MarineEarth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
2 Faculty of Engineering, Toyo University, 2100 Kuzirai, Kawagoe 350-8585, Japan
Correspondence
Yuichi Nogi
nogiy{at}jamstec.go.jp
| ABSTRACT |
|---|
|
|
|---|
| MAIN TEXT |
|---|
|
|
|---|
Strains c931T, c941T, d943, c952, d954 and c959T were isolated at a depth of 24062409 m from a deep-sea sediment, using sterilized mud samplers on the unmanned submersible Kaiko positioned off Matsuzaki in Suruga Bay (34° 36.55' N 138° 34.77' E). The following reference strains were used. Shewanella benthica ATCC 43992T and Shewanella pealeana ATCC 700345T were obtained from the American Type Culture Collection (Manassas, VA, USA), Shewanella marinintestina JCM 11558T, Shewanella sairae JCM 11563T and Shewanella schlegeliana JCM 11561T were obtained from the Japan Collection of Microorganisms (Wako, Japan) and Shewanella gelidimarina ACAM 456T was obtained from the Australian Collection of Antarctic Micro-organisms (Hobart, Tasmania, Australia). Shewanella pneumatophori SCRC-2738T was obtained from Dr Kikue Hirota (Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology, Sapporo, Japan). Shewanella violacea DSS12T was from our laboratory stock. These bacteria were incubated on marine agar 2216 (Difco). Agar plates were incubated aerobically for 23 days at the optimum temperature. Unless indicated otherwise, physiological tests were performed with a slight modification (use of artificial seawater; 1x artificial seawater consists of 3 % NaCl, 0.07 % KCl, 1.08 % MgCl2.6H2O, 0.54 % MgSO4.7H2O, 0.1 % CaCl2.2H2O) of the general procedures described by Barrow & Feltham (1993)
and Baumann et al. (1972)
. Optimal temperatures for growth were determined on the basis of optical density in marine broth 2216 (Difco). Acid production from sugars was assessed using modified OF medium (Hugh & Leifson 1953
) containing 0.5x artificial seawater, 0.05 % (NH4)2SO4, 0.01 % yeast extract (Difco), 0.05 % Tris base, 0.5 % agar, 0.003 % bromothymol blue and 1 % test sugar (pH was adjusted to 7.1 at 20 °C), with incubation at the optimum temperature. Salt-tolerance tests were performed using medium containing 0.5 % Pepton (Difco), 0.5 % yeast extract, 0.32 % MgSO4.7H2O and 0.1 % K2HPO4, with NaCl concentrations of 015 % (w/v).
Cellular fatty acids were extracted and analysed as described by Komagata & Suzuki (1987)
. Isolated strains were cultured in marine broth 2216 medium at optimal temperatures. Cells were washed twice with 0.7 % NaCl at 4 °C; this was followed by centrifugation at 8000 g and freeze-drying. Dried cells (20 mg) were placed in Teflon-lined, screw-capped tubes containing 2 ml anhydrous methanolic HCl and heated to 100 °C for 3 h. After cooling, 1 ml water was added and the fatty acid methyl esters were extracted with n-hexane. Samples were analysed using a Shimadzu model GCMS-QP5050A gasliquid chromatograph/mass spectrometer with a DB-5MS column (J&W Scientific). Isoprenoid quinones were extracted with chloroform/methanol (2 : 1) from dried cells (200 mg) and purified using TLC. The purified isoprenoid quinones were analysed using reversed-phase HPLC (Komagata & Suzuki, 1987
).
Chromosomal DNA was purified by using a standard method (Saito & Miura, 1963
). The DNA G+C content was determined using reversed-phase HPLC (Tamaoka & Komagata, 1984
). For analysis of relatedness, DNADNA hybridization was carried out at 40 °C for 4 h and measured fluorometrically using the method of Ezaki et al. (1989)
.
16S rRNA and gyrB gene sequences were obtained by direct sequencing of PCR-amplified DNA as described previously (Kato et al., 1998
; Yamamoto & Harayama, 1995
). Nucleotide substitution rates (Knuc) (Kimura, 1980
) were determined and a distance matrix tree was constructed with the neighbour-joining method (Saitou & Nei, 1987
), using the CLUSTAL X program (Thompson et al., 1997
). Alignment gaps and unidentified base positions were not taken into consideration in the calculations. The topology of the phylogenetic tree was evaluated by performing bootstrap analysis with 1000 replicates. The GenBank/DDBJ/EMBL accession numbers for the 16S rRNA and gyrB gene sequences of the isolates are shown in Fig. 1
; reference sequences were obtained from the GenBank database.
|
|
The results of the phylogenetic analyses using 16S rRNA and gyrB gene sequences are shown in Fig. 1
. These results support the conclusions described below and further clarify the taxonomic and phylogenetic positions of the novel isolates among members of the genus Shewanella and related genera. Strains c931T, d954 and c952 were most closely related to S. schlegeliana (98.698.8 % similarity for 16S rRNA, 86.086.5 % similarity for gyrB), strains c941T and d943 were most closely related to S. gelidimarina (97.798.0 % similarity for 16S rRNA, 86.887.4 % similarity for gyrB) and strain c959T was most closely related to S. gelidimarina (97.1 % similarity for 16S rRNA), but showed less than 80 % gyrB gene sequence similarity to Shewanella species. The generally recommended and accepted criteria for delineating bacterial species state that strains with 16S rRNA gene sequence dissimilarity greater than 3 % are considered to belong to separate species (Stackebrandt & Goebel, 1994
; Stackebrandt et al., 2002
); within the genus Shewanella, strains with gyrB gene sequence dissimilarity greater than 10 % are considered to belong to separate species (Venkateswaran et al., 1999
). However, bacterial strains with gyrB gene sequences that differ by less than 10 % cannot be allocated to the same species without support from DNADNA relatedness studies. The generally recognized criteria for delineating bacterial species state that strains with a DNADNA relatedness of less than 70 %, as measured by hybridization, represent separate species (Wayne et al., 1987
).
The results of DNADNA hybridization analysis indicated that the novel isolates fell into three groups (Table 2
), the same grouping revealed by phenotypic characteristics and phylogenetic analyses. There was more than 70 % DNA relatedness among the strains in each group, and each group was clearly separate, representing distinct species (i.e. showing significantly less than 70 % relatedness) according to the recommendations of Wayne et al. (1987)
. This, together with the other results shown in Table 1
and Fig. 1
, suggests that the isolated strains represent three novel species of the genus Shewanella.
|
3 (eicosapentaenoic acid), strain c941T contained large amounts of iso-C13 : 0 and C15 : 0 (pentadecanoic acid) and small amounts of C16 : 0 and strain c959T contained large amounts of C16 : 1 and did not contain C20 : 5
3.
|
On the basis of the phenotypic, genotypic and phylogenetic data, it is logical to conclude that the deep-sea isolates we studied are members of the genus Shewanella and that they represent three novel species within this genus. We propose the names Shewanella kaireitica sp. nov. (type strain c931T), Shewanella abyssi sp. nov. (type strain c941T) and Shewanella surugensis sp. nov. (type strain c959T).
Description of Shewanella kaireitica sp. nov.
Shewanella kaireitica (kai.rei'tic.a. N.L. n. Kairei a research vessel; L. fem. suff. -tica adjectival suffix meaning belonging to; N.L. fem. adj. kaireitica belonging to the research vessel Kairei).
Cells are rod-shaped; cell width ranges from 0.8 to 1.0 µm and cell length ranges from 2.5 to 3.0 µm. Cells are Gram-negative and motile by means of single, unsheathed, polar flagella. Colonies on marine agar 2216 are entire, smooth, semitranslucent and salmon-coloured; 24 mm in diameter after 12 days incubation at 20 °C. The bacterium is psychrotolerant. Exhibits optimal growth at NaCl concentrations of approximately 35 %; able to grow at 7 % NaCl (with the exception of strain d954). No growth occurs in the absence of NaCl. Optimal temperature for growth is 2425 °C. No growth at temperatures above 30 °C. Facultatively anaerobic chemo-organotroph, having both respiratory and fermentative types of metabolism. Catalase and cytochrome oxidase tests are positive. H2S is produced. Nitrate is reduced to N2. Acid is formed oxidatively from cellobiose, D-fructose, D-galactose, D-glucose, maltose and D-sorbitol. No acid is produced from L-arabinose, glycerol, myo-inositol, D-lactose, D-mannitol, D-mannose, D-raffinose, L-rhamnose, sucrose, D-trehalose or xylose. The G+C content of the DNA is approximately 43.0 mol%. The major isoprenoid quinone is Q-7. The predominant cellular fatty acids are iso-C13 : 0, iso-C15 : 0, C16 : 0 and C16 : 1.
The type strain, c931T (=JCM 11836T=DSM 17170T), and strains c952 and d954 were isolated from deep-sea sediment in Suruga Bay, Japan.
Description of Shewanella abyssi sp. nov.
Shewanella abyssi (a.bys'si. N.L. gen. n. abyssi from the abyss).
Cells are rod-shaped; cell width ranges from 0.8 to 1.0 µm and cell length ranges from 2.0 to 2.5 µm. Cells are Gram-negative and motile by means of single, unsheathed, polar flagella. Colonies on marine agar 2216 are entire, smooth, semitranslucent and salmon-coloured; 24 mm in diameter after 23 days incubation at 10 °C. The bacterium is psychrotolerant. Optimal growth occurs at a NaCl concentrations of 35 %. No growth occurs in the absence of NaCl. The optimal temperature for growth is 10 °C. No growth occurs at temperatures above 25 °C. Facultatively anaerobic chemo-organotroph, having both respiratory and fermentative types of metabolism. Catalase and cytochrome oxidase tests are positive. H2S and indole are produced. Nitrate is reduced to nitrite; nitrite is reduced to N2. Acid is formed oxidatively from cellobiose. No acid is produced from L-arabinose, D-fructose, D-galactose, D-glucose, glycerol, myo-inositol, D-lactose, maltose, D-mannitol, D-mannose, D-raffinose, L-rhamnose, D-sorbitol, sucrose, D-trehalose or xylose. The G+C content of the DNA is approximately 43.5 mol%. The major isoprenoid quinones are Q-7 and Q-8. The predominant cellular fatty acids are iso-C13 : 0, iso-C15 : 0, C16 : 0 and C16 : 1.
The type strain, c941T (=JCM 13041T=DSM 17171T), and strain d943 were isolated from deep-sea sediment in Suruga Bay, Japan.
Description of Shewanella surugensis sp. nov.
Shewanella surugensis (su.ru.gen'sis. N.L. fem. adj. surugensis pertaining to Suruga Bay, where the type strain was isolated).
Cells are rod-shaped; cell width ranges from 0.4 to 0.6 µm and cell length ranges from 3.2 to 4.0 µm. Cells are Gram-negative and motile by means of single, unsheathed, polar flagella. Colonies on marine agar 2216 are entire, smooth, semitranslucent and cream-coloured; 24 mm in diameter after 23 days incubation at 10 °C. The bacterium is psychrotolerant. Optimal growth occurs at an NaCl concentration of approximately 3 %. No growth occurs in the absence of NaCl. The optimal temperature for growth is 13 °C. No growth occurs at temperatures above 25 °C. Facultatively anaerobic chemo-organotroph, having both respiratory and fermentative types of metabolism. The catalase test is positive. The cytochrome oxidase test is negative. Does not produce H2S. Nitrate is reduced to nitrite. Acid is formed oxidatively from D-fructose, D-glucose, glycerol, D-mannose and sucrose. No acid is produced from L-arabinose, cellobiose, D-galactose, myo-inositol, D-lactose, maltose, D-mannitol, D-raffinose, L-rhamnose, D-sorbitol, D-trehalose or xylose. The G+C content of the DNA is approximately 40.0 mol%. The major isoprenoid quinone is Q-8. The predominant cellular fatty acids are iso-C13 : 0, iso-C15 : 0 and C16 : 1.
The type strain, c959T (=JCM 11835T=DSM 17177T), was isolated from deep-sea sediment in Suruga Bay, Japan.
| ACKNOWLEDGEMENTS |
|---|
| REFERENCES |
|---|
|
|
|---|
Barrow, G. I. & Feltham, R. K. A. (1993). Cowan and Steel's Manual for the Identification of Medical Bacteria, 3rd edn. New York: Cambridge University Press.
Baumann, L., Baumann, P., Mandel, M. & Allen, R. D. (1972). Taxonomy of aerobic marine eubacteria. J Bacteriol 110, 402429.
Bowman, J. P., McCammon, S. A., Nichols, D. S., Skerratt, J. H., Rea, S. M., Nichols, P. D. & McMeekin, T. A. (1997). Shewanella gelidimarina sp. nov. and Shewanella frigidimarina sp. nov., novel Antarctic species with the ability to produce eicosapentaenoic acid (20 : 5
3) and grow anaerobically by dissimilatory Fe(III) reduction. Int J Syst Bacteriol 47, 10401047.
DeLong, E. F., Franks, D. G. & Yayanos, A. A. (1997). Evolutionary relationships of cultivated psychrophilic and barophilic deep-sea bacteria. Appl Environ Microbiol 63, 21052108.[Abstract]
Ezaki, T., Hashimoto, Y. & Yabuuchi, E. (1989). Fluorometric deoxyribonucleic acid-deoxyribonucleic acid hybridization in microdilution wells as an alternative to membrane filter hybridization in which radioisotopes are used to determine genetic relatedness among bacterial strains. Int J Syst Bacteriol 39, 224229.
Gauthier, G., Gauthier, M. & Christen, R. (1995). Phylogenetic analysis of the genera Alteromonas, Shewanella, and Moritella using genes coding for small-subunit rRNA sequences and division of the genus Alteromonas into two genera, Alteromonas (emended) and Pseudoalteromonas gen. nov., and proposal of twelve new species combinations. Int J Syst Bacteriol 45, 755761.
Hazel, J. R. & Williams, E. E. (1990). The role of alterations in membrane lipid composition in enabling physiological adaptation of organisms to their physical environment. Prog Lipid Res 29, 167227.[CrossRef][Medline]
Hirota, K., Nodasaka, Y., Orikasa, Y., Okuyama, H. & Yumoto, I. (2005). Shewanella pneumatophori sp. nov., an eicosapentaenoic acid-producing marine bacterium isolated from the intestines of Pacific mackerel (Pneumatophorus japonicus). Int J Syst Evol Microbiol 55, 23552359.
Hugh, R. & Leifson, E. (1953). The taxonomic significance of fermentative versus oxidative metabolism of carbohydrates by various gram negative bacteria. J Bacteriol 66, 2226.
Ivanova, E. P., Sawabe, T., Gorshkova, N. M., Svetashev, V. I., Mikhailov, V. V., Nicolau, D. V. & Christen, R. (2001). Shewanella japonica sp. nov. Int J Syst Evol Microbiol 51, 10271033.[Abstract]
Ivanova, E. P., Sawabe, T., Hayashi, K., Gorshkova, N. M., Zhukova, N. V., Nedashkovskaya, O. I., Mikhailov, V. V., Nicolau, D. V. & Christen, R. (2003). Shewanella fidelis sp. nov., isolated from sediments and sea water. Int J Syst Evol Microbiol 53, 577582.
Ivanova, E. P., Nedashkovskaya, O. I., Sawabe, T., Zhukova, N. V., Frolova, G. M., Nicolau, D. V., Mikhailov, V. V. & Bowman, J. P. (2004). Shewanella affinis sp. nov., isolated from marine invertebrates. Int J Syst Evol Microbiol 54, 10891093.
Kato, C. & Nogi, Y. (2001). Correlation between phylogenetic structure and function: examples from deep-sea Shewanella. FEMS Microbiol Ecol 35, 223230.[CrossRef][Medline]
Kato, C., Li, L., Nogi, Y., Nakamura, Y., Tamaoka, J. & Horikoshi, K. (1998). Extremely barophilic bacteria isolated from the Mariana Trench, Challenger Deep, at a depth of 11,000 meters. Appl Environ Microbiol 64, 15101513.
Kimura, M. (1980). A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. J Mol Evol 16, 111120.[CrossRef][Medline]
Komagata, K. & Suzuki, K. (1987). Lipid and cell-wall analysis in bacterial systematics. Methods Microbiol 19, 161207.
Leonardo, M. R., Moser, D. P., Barbieri, E., Branther, C. A., MacGregor, B. J., Paster, B. J., Stackebrandt, E. & Nealson, K. H. (1999). Shewanella pealeana sp. nov., a member of the microbial community associated with the accessory nidamental gland of the squid Loligo pealei. Int J Syst Bacteriol 49, 13411351.
MacDonell, M. T. & Colwell, R. R. (1985). Phylogeny of the Vibrionaceae, and recommendation for two new genera, Listonella and Shewanella. Syst Appl Microbiol 6, 171182.
Makemson, J. C., Fulayfil, N. R., Landry, W., Van Ert, L. M., Wimpee, C. F., Widder, E. A. & Case, J. F. (1997). Shewanella woodyi sp. nov., an exclusively respiratory luminous bacterium isolated from the Alboran Sea. Int J Syst Bacteriol 47, 10341039.
Margesin, R. & Nogi, Y. (2004). Psychropiezophilic microorganisms. Cell Mol Biol 50, 429436.[Medline]
Myers, C. R. & Nealson, K. H. (1988). Bacterial manganese reduction and growth with manganese oxide as the sole electron acceptor. Science 240, 13191321.
Nogi, Y., Kato, C. & Horikoshi, K. (1998). Taxonomic studies of deep-sea barophilic Shewanella strains and description of Shewanella violacea sp. nov. Arch Microbiol 170, 331338.[CrossRef][Medline]
Saito, H. & Miura, K. (1963). Preparation of transforming deoxyribonucleic acid by phenol treatment. Biochim Biophys Acta 72, 612629.
Saitou, N. & Nei, M. (1987). The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4, 406425.[Abstract]
Satomi, M., Oikawa, H. & Yano, Y. (2003). Shewanella marinintestina sp. nov., Shewanella schlegeliana sp. nov. and Shewanella sairae sp. nov., novel eicosapentaenoic-acid-producing marine bacteria isolated from sea-animal intestines. Int J Syst Evol Microbiol 53, 491499.
Semple, K. M. & Westlake, D. W. S. (1987). Characterization of iron reducing Alteromonas putrefaciens strains from oil field fluids. Can J Microbiol 35, 925931.
Simidu, U., Kita-Tsukamoto, K., Yamasato, T. & Yotsu, M. (1990). Taxonomy of four marine bacterial strains that produce tetrodotoxin. Int J Syst Bacteriol 40, 331336.
Stackebrandt, E. & Goebel, B. M. (1994). Taxonomic note: a place for DNA-DNA reassociation and 16S rRNA sequence analysis in the present species definition in bacteriology. Int J Syst Bacteriol 44, 846849.
Stackebrandt, E., Frederiksen, W., Garrity, G. M. & 10 other authors (2002). Report of the ad hoc committee for the re-evaluation of the species definition in bacteriology. Int J Syst Evol Microbiol 52, 10431047.[Abstract]
Tamaoka, J. & Komagata, K. (1984). Determination of DNA base composition by reverse-phase high-performance liquid chromatography. FEMS Microbiol Lett 25, 125128.
Thompson, J. D., Gibson, T. J., Plewniak, F., Jeanmougin, F. & Higgins, D. G. (1997). The CLUSTAL_X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res 25, 48764882.
Venkateswaran, K., Moser, D. P., Dollhopf, M. E. & 10 other authors (1999). Polyphasic taxonomy of the genus Shewanella and description of Shewanella oneidensis sp. nov. Int J Syst Bacteriol 49, 705724.
Wayne, L. G., Brenner, D. J., Colwell, R. R. & 9 other authors (1987). Report of the ad hoc committee on reconciliation of approaches of bacterial systematics. Int J Syst Bacteriol 37, 463464.
Yamamoto, S. & Harayama, S. (1995). PCR amplification and direct sequencing of gyrB genes with universal primers and their application to the detection and taxonomic analysis of Pseudomonas putida strains. Appl Environ Microbiol 61, 11041109.[Abstract]
This article has been cited by other articles:
![]() |
M. Miyazaki, Y. Nogi, Y. Fujiwara, and K. Horikoshi Psychromonas japonica sp. nov., Psychromonas aquimarina sp. nov., Psychromonas macrocephali sp. nov. and Psychromonas ossibalaenae sp. nov., psychrotrophic bacteria isolated from sediment adjacent to sperm whale carcasses off Kagoshima, Japan Int J Syst Evol Microbiol, July 1, 2008; 58(7): 1709 - 1714. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Miyazaki, Y. Nogi, Y. Ohta, Y. Hatada, Y. Fujiwara, S. Ito, and K. Horikoshi Microbulbifer agarilyticus sp. nov. and Microbulbifer thermotolerans sp. nov., agar-degrading bacteria isolated from deep-sea sediment Int J Syst Evol Microbiol, May 1, 2008; 58(5): 1128 - 1133. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Miyazaki, Y. Nogi, Y. Fujiwara, M. Kawato, K. Kubokawa, and K. Horikoshi Neptunomonas japonica sp. nov., an Osedax japonicus symbiont-like bacterium isolated from sediment adjacent to sperm whale carcasses off Kagoshima, Japan Int J Syst Evol Microbiol, April 1, 2008; 58(4): 866 - 871. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Kim, K. S. Baik, M. S. Kim, B.-M. Jung, T.-S. Shin, G.-H. Chung, M. S. Rhee, and C. N. Seong Shewanella haliotis sp. nov., isolated from the gut microflora of abalone, Haliotis discus hannai Int J Syst Evol Microbiol, December 1, 2007; 57(12): 2926 - 2931. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |