|
|
||||||||
1 Botany Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
2 School of Biology, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK
Correspondence
Wael N. Hozzein
hozzein29{at}yahoo.com
| ABSTRACT |
|---|
|
|
|---|
A scanning electron micrograph of strain S155T is available as supplementary material with the online version of this paper.
| MAIN TEXT |
|---|
|
|
|---|
An interesting organism was isolated during a routine screening programme for novel bioactive actinomycetes from environmental samples from different regions of Egypt. The strain, designated S155T, had a colonial morphology typical of members of the genus Streptomyces. The aim of the present investigation was to establish the taxonomic position of this isolate using a combination of genotypic and phenotypic procedures. It is apparent from the results that the organism should be recognized as representing a novel species of the genus Streptomyces.
Strain S155T was isolated on an M1 agar plate (Mincer et al., 2002
) which had been inoculated with a soil suspension and incubated at 28 °C for 2 weeks. The soil sample had been collected from a sand dune at Borg El-Arab in Egypt. The organism was maintained on modified Bennett's agar slopes (Jones, 1949
) and as glycerol suspensions of hyphae and spores (20 %, v/v) at –20 °C. Biomass for chemotaxonomic and molecular systematic studies was grown in shake flasks of modified Bennett's broth (Jones, 1949
) at 28 °C for 7 days, harvested by centrifugation and washed twice with distilled water. Biomass for chemotaxonomic studies was freeze-dried and that for the molecular systematic work was stored at –20 °C.
Extraction of chromosomal DNA, PCR-mediated amplification of the 16S rRNA gene and direct sequencing of the purified products were carried out using a standard procedure (Kim et al., 2000
). The resultant 16S rRNA gene sequence was aligned manually with corresponding sequences of the type strains of available Streptomyces species retrieved from the DDBJ/EMBL/GenBank databases and then with representatives of phylogenetically close Streptomyces species highlighted by using BLAST (Altschul et al., 1997
). Multiple alignment and phylogenetic analysis were achieved using the CLUSTAL_X 1.8 program (Thompson et al., 1997
) and MEGA version 3.1 software (Kumar et al., 2004
); phylogenetic trees were inferred using the least-squares (Fitch & Margoliash, 1967
), maximum-parsimony (Kluge & Farris, 1969
) and neighbour-joining (Saitou & Nei, 1987
) tree-making algorithms. Evolutionary distance matrices were generated for the least-squares and neighbour-joining methods after Jukes & Cantor (1969)
and the unrooted tree topologies were evaluated by bootstrap analysis (Felsenstein, 1985
) of the neighbour-joining dataset based on 1000 resamplings. The root position of the neighbour-joining tree was estimated using Streptomyces scabrisporus KM-4927T as the outgroup. It was evident from the comprehensive phylogenetic analyses that strain S155T formed a distinct phyletic line towards the periphery of the Streptomyces 16S rRNA gene tree (data not shown).
The isolate was examined for a range of chemotaxonomic and morphological properties considered to be characteristic of the genus Streptomyces. Colonial features, notably aerial spore mass colour, substrate mycelial pigmentation and the colour of diffusible pigments, were recorded on glycerol-asparagine agar (ISP medium 5), inorganic salts-starch agar (ISP medium 4), oatmeal agar (ISP medium 3), tryptone-yeast extract agar (ISP medium 1) and yeast extract-malt extract agar (ISP medium 2), as described by Shirling & Gottlieb (1966)
, and on modified Bennett's agar (Jones, 1949
) and nutrient agar (Waksman, 1961
); all plates were incubated at 28 °C for 2 weeks. Spore arrangement and spore surface ornamentation were observed by examining gold-coated, dehydrated preparations from a 14-day-old culture grown on modified Bennett's agar (Jones, 1949
) at 28 °C, using a Cambridge Stereoscan 240 scanning electron microscope and the procedure described by O'Donnell et al. (1993)
. Standard chromatographic procedures were used to extract and analyse the isomeric forms of diaminopimelic acid (Hasegawa et al., 1983
), fatty acids (Sutcliffe, 2000
), isoprenoid quinones (Minnikin et al., 1984
; Collins, 1985
), polar lipids (Minnikin et al., 1984
) and whole-organism sugars (Staneck & Roberts, 1974
).
The chemical and morphological properties of the isolate are in line with its classification in the genus Streptomyces. The organism forms an extensively branched substrate mycelium. At maturity, when adequate aerial mycelium is produced, the aerial hyphae differentiate into short, straight to flexuous chains of smooth-surfaced spores. Synnemata-like structures were formed from hyphae that wrapped together to form long ropes (see Supplementary Fig. S1 in IJSEM Online). Sclerotia, zoospores or sporangia were not observed. Growth was moderate to abundant on all tested media. Aerial mycelium was light greyish red to blackish red and the substrate hyphae varied from dark red to reddish black. No diffusible pigments were produced except on inorganic salts-starch agar medium (ISP medium 4) (deep greyish red).
The strain contained major amounts of LL-diaminopimelic acid, glucose and galactose, but no diagnostic sugars, in whole-organism hydrolysates (wall chemotype I sensu Lechevalier & Lechevalier, 1970
), tetra-, hexa- and octahydrogenated menaquinones as major isoprenologues (menaquinone type 4b sensu Kroppenstedt, 1985
) and a polar lipid pattern consisting of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and unidentified phospholipids (phospholipid type II sensu Lechevalier et al., 1977
). The fatty acid profile was composed mainly of saturated straight-chain and iso- and anteiso-branched-chain components. The major fatty acid components were iso-C16 : 0, anteiso-C15 : 0, iso-C14 : 0, anteiso-C17 : 0, iso-C15 : 0 and iso-C15 : 0 2-OH (fatty acid type 2c sensu Kroppenstedt, 1985
). This chemical profile and the morphological properties of strain S155T are clearly consistent with its assignment to the genus Streptomyces (Williams et al., 1989
; Manfio et al., 1995
).
It is evident from Fig. 1
that strain S155T forms a distinct phyletic line. It is most closely related to the type strains of Streptomyces thermoalcalitolerans (97.1 %), Streptomyces ruber (97 %), Streptomyces rubiginosus (97.0 %) and Streptomyces roseiscleroticus (96.9 %); it also shares 96.8 % 16S rRNA similarity with the type strains of Streptomyces cellulosae, Streptomyces lavendulae subsp. lavendulae, Streptomyces ochraceiscleroticus and Streptomyces rimosus subsp. rimosus. DNA–DNA relatedness studies were not carried out between strain S155T and its closest phylogenetic neighbours as representatives of Streptomyces species with high 16S rRNA gene sequence similarities are known to share low DNA–DNA relatedness (Kim & Goodfellow, 2002
; Manfio et al., 2003
; Kim et al., 2006
; Xu et al., 2006
), that is, values well below the 70 % cut-off point recommended for the delineation of genomic species (Wayne et al., 1987
).
|
It is evident from Table 1
that strain S155T can be distinguished from the type strains of its most immediate phylogenetic neighbours of the genus Streptomyces by using a combination of phenotypic properties. Additional phenotypic properties are cited in the species description. In this regard, the morphological features and degradation of organic compounds were very significant in distinguishing strain S155T from its phylogenetic neighbours. It was reported in previous studies that differential morphological and pigmentation features are especially significant for the delineation of members of phylogenetically related Streptomyces species (Labeda & Lyons, 1991
; Labeda et al., 1997
; Kim et al., 2000
; Manfio et al., 2003
).
|
Description of Streptomyces synnematoformans sp. nov.
Streptomyces synnematoformans (syn.ne.ma.to.for'mans. Gr. prep. syn in company with, together with; Gr. n. nema thread; N.Gr. n. synnema threads wrapping together; L. part. adj. formans forming; N.L. part. adj. synnematoformans synnemata-forming, referring to the ability of the organism to form synnemata).
Aerobic, Gram-positive, non-acid–alcohol-fast actinomycete which forms an extensively branched substrate mycelium that carries aerial hyphae which differentiate into short, straight to flexuous chains of smooth-surfaced spores (1–1.5 µm). Forms synnemata-like structures but not sclerotia. A greyish- to blackish-red aerial spore mass and a dark-red to reddish-black substrate mycelium are formed on synthetic agar media. A deep greyish-red diffusible pigment is produced on inorganic salts-starch agar. Grows from 10 to 37 °C and from pH 6.5 to 9.5. Does not hydrolyse arbutin or degrade adenine or uric acid. D-Cellobiose, D-fructose, D-galactose, D-glucose, maltose, D-mannose and trehalose are used as sole carbon sources for energy and growth, but not L-arabitol, meso-erythritol, D-melezitose, D-salicin, D-sorbitol or D-xylitol (at 1 %, w/v). Similarly, pyruvate is used as a sole carbon source, but not acetate, malonate or succinate (all 0.1 %, w/v). Grows in the presence of 7 % (w/v) NaCl. Additional phenotypic properties are shown in Table 1
.
The type and only strain, S155T (=CGMCC 4.2055T =DSM 41902T), was isolated from a sand dune soil collected at Borg El-Arab in Egypt. The species description is based on a single strain and hence serves as a description of the type strain.
| ACKNOWLEDGEMENTS |
|---|
| REFERENCES |
|---|
|
|
|---|
Altschul, S. F., Madden, T. L., Schäffer, A. A., Zhang, J., Zhang, Z., Miller, W. & Lipman, D. J. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25, 3389–3402.
Baur, S., Niehaus, J., Karagouni, A. D., Katsifas, E. A., Chalkou, K., Meintanis, C., Jones, A. L., Goodfellow, M., Ward, A. C. & other authors (2006). Fluostatins C–E, novel members of the fluostatin family produced by Streptomyces strain Acta 1383. J Antibiot (Tokyo) 59, 293–297.[Medline]
Bouchek-Mechiche, K., Gardan, L., Andrivon, D. & Normand, P. (2006). Streptomyces turgidiscabies and Streptomyces reticuliscabies: one genomic species, two pathogenic groups. Int J Syst Evol Microbiol 56, 2771–2776.
Collins, M. D. (1985). Isoprenoid quinone analysis in bacterial classification and identification. In Chemical Methods in Bacterial Systematics, pp. 267–287. Edited by M. Goodfellow & D. E. Minnikin. London: Academic Press.
Dietera, A., Hamm, A., Fiedler, H.-P., Goodfellow, M., Müller, W. E. G., Brun, R., Beil, W. & Brigmann, G. (2003). Pyrocoll, an antibiotic, antiparasitic and antitumor compound produced by a novel alkaliphilic Streptomyces strain. J Antibiot (Tokyo) 56, 639–646.[Medline]
Euzéby, J. P. (1997). List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet. Int J Syst Bacteriol 47, 590–592.
Felsenstein, J. (1985). Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39, 783–791.[CrossRef]
Fiedler, H.-P., Bruntner, C., Bull, A. T., Ward, A. C., Goodfellow, M., Potterat, O., Puder, C. & Mihm, G. (2005). Marine actinomycetes as a source of novel secondary metabolites. Antonie van Leeuwenhoek 87, 37–42.[CrossRef][Medline]
Fitch, W. M. & Margoliash, E. (1967). Construction of phylogenetic trees: a method based on mutation distances as estimated from cytochrome c sequences is of general applicability. Science 155, 279–284.
Gordon, R. E. (1967). The taxonomy of soil bacteria. In The Ecology of Soil Bacteria, pp. 293–321. Edited by T. R. G. Gray & D. Parkinson. Liverpool: Liverpool University Press.
Gordon, R. E. & Mihm, J. M. (1962). Identification of Nocardia caviae (Erikson) nov. com. Ann NY Acad Sci 98, 628–636.[CrossRef]
Hasegawa, T., Takizawa, M. & Tanida, S. (1983). A rapid analysis for chemical grouping of aerobic actinomycetes. J Gen Appl Microbiol 29, 319–322.[CrossRef]
Jones, K. L. (1949). Fresh isolates of actinomycetes in which the presence of sporogenous aerial mycelia is a fluctuating characteristic. J Bacteriol 57, 141–145.
Jukes, T. H. & Cantor, C. R. (1969). Evolution of protein molecules. In Mammalian Protein Metabolism, vol. 3, pp. 21–123. Edited by H. N. Munro. New York: Academic Press.
Kim, S. B. & Goodfellow, M. (2002). Streptomyces thermospinisporus sp. nov., a moderately thermophilic carboxydotrophic streptomycete isolated from soil. Int J Syst Evol Microbiol 52, 1225–1228.[Abstract]
Kim, B., Sahin, N., Minnikin, D. E., Zakrazewska-Czerwinska, J., Mordarski, M. & Goodfellow, M. (1999). Classification of thermophilic streptomycetes, including the description of Streptomyces thermoalcalitolerans sp. nov. Int J Syst Bacteriol 49, 7–17.
Kim, S. B., Brown, R., Oldfield, C., Gilbert, S. C., Iliarionov, S. & Goodfellow, M. (2000). Gordonia amicalis sp. nov., a novel dibenzothiophene-desulphurizing actinomycete. Int J Syst Evol Microbiol 50, 2031–2036.[Abstract]
Kim, H. J., Lee, S. C. & Huang, B. K. (2006). Streptomyces cheonanensis sp. nov., a novel streptomycete with antifungal activity. Int J Syst Evol Microbiol 56, 471–475.
Kluge, A. G. & Farris, F. S. (1969). Quantitative phyletics and the evolution of anurans. Syst Zool 18, 1–32.
Kroppenstedt, R. M. (1985). Fatty acid and menaquinone analysis of actinomycetes and related organisms. In Chemical Methods in Bacterial Systematics, pp. 173–199. Edited by M. Goodfellow & D. E. Minnikin. London: Academic Press.
Kumar, S., Tamura, K. & Nei, M. (2004). MEGA3: integrated software for molecular evolutionary genetics analysis and sequence alignment. Brief Bioinform 5, 150–163.
Labeda, D. P. & Lyons, A. J. (1991). Deoxyribonucleic acid relatedness among species of the Streptomyces cyaneus cluster. Syst Appl Microbiol 14, 158–164.
Labeda, D. P., Lechevalier, M. P. & Testa, R. T. (1997). Streptomyces stramineus sp. nov., a new species of the verticillate streptomycetes. Int J Syst Bacteriol 47, 747–753.
Lechevalier, H. A. & Lechevalier, M. P. (1970). A critical evaluation of the genera of aerobic actinomycetes. In The Actinomycetales, pp. 393–405. Edited by H. Prauser. Jena: VEB Gustav Fischer.
Lechevalier, M. P., De Bièvre, C. & Lechevalier, H. A. (1977). Chemotaxonomy of aerobic actinomycetes: phospholipid composition. Biochem Syst Ecol 5, 249–260.[CrossRef]
Manfio, G. P., Zakrzewska-Czerwinska, J., Atalan, E. & Goodfellow, M. (1995). Towards minimal standards for the description of Streptomyces species. Biotekhnologiia 8, 228–237.
Manfio, G. P., Atalan, E., Zakrzewska-Czerwinska, J., Mordarski, M., Rodriguez, C., Collins, M. D. & Goodfellow, M. (2003). Classification of novel soil streptomycetes as Streptomyces aureus sp. nov., Streptomyces laceyi sp. nov. and Streptomyces sanglieri sp. nov. Antonie van Leeuwenhoek 83, 245–255.[CrossRef][Medline]
Mincer, T. J., Gensen, P. R., Kauffman, C. A. & Fenical, W. (2002). Widespread and persistent populations of a major new marine actinomycete taxon in ocean sediments. Appl Environ Microbiol 68, 5005–5011.
Minnikin, D. E., O'Donnell, A. G., Goodfellow, M., Alderson, G., Athalye, M., Schaal, A. & Parlett, J. H. (1984). An integrated procedure for the extraction of bacterial isoprenoid quinones and polar lipids. J Microbiol Methods 2, 233–241.[CrossRef]
O'Donnell, A. G., Falconer, C., Goodfellow, M., Ward, A. C. & Williams, E. (1993). Biosystematics and diversity amongst novel carboxydotrophic actinomycetes. Antonie van Leeuwenhoek 64, 325–340.[CrossRef][Medline]
Saitou, N. & Nei, M. (1987). The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4, 406–425.[Abstract]
Shirling, E. B. & Gottlieb, D. (1966). Methods for characterization of Streptomyces species. Int J Syst Bacteriol 16, 313–340.[Medline]
Shirling, E. B. & Gottlieb, D. (1968a). Cooperative description of type cultures of Streptomyces. II. Species descriptions from first study. Int J Syst Bacteriol 18, 69–189.
Shirling, E. B. & Gottlieb, D. (1968b). Cooperative description of type cultures of Streptomyces. III. Additional descriptions from first and second studies. Int J Syst Bacteriol 18, 279–392.
Shirling, E. B. & Gottlieb, D. (1969). Cooperative description of type cultures of Streptomyces. IV. Species descriptions from the second, third and fourth studies. Int J Syst Bacteriol 19, 391–512.
Shirling, E. B. & Gottlieb, D. (1972). Cooperative description of type strains of Streptomyces. V. Additional descriptions. Int J Syst Bacteriol 22, 265–394.
Society of American Bacteriologists (1957). Manual of Microbiological Methods. New York: McGraw-Hill.
Staneck, J. L. & Roberts, G. D. (1974). Simplified approach to identification of aerobic actinomycetes by thin-layer chromatography. Appl Microbiol 28, 226–231.[Medline]
Sutcliffe, I. C. (2000). Characterisation of a lipomannan lipoglycan from the mycolic acid containing actinomycete Dietzia maris. Antonie van Leeuwenhoek 78, 195–201.[CrossRef][Medline]
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, 4876–4882.
Waksman, S. A. (1961). The Actinomycetes, vol. 2, Classification, Identification and Descriptions of Genera and Species. Baltimore: Williams & Wilkins.
Wayne, L. G., Brenner, D. J., Colwell, R. R., Grimont, P. A. D., Kandler, O., Krichevsky, M. I., Moore, L. H., Moore, W. E. C., Murray, R. G. E. & other authors (1987). International Committee on Bacterial Systematics. Report of the ad hoc committee on reconciliation of approaches to bacterial systematics. Int J Syst Bacteriol 37, 463–464.
Williams, S. T., Goodfellow, M., Alderson, G., Wellington, E. M. H., Sneath, P. H. A. & Sackin, M. J. (1983). Numerical classification of Streptomyces and related genera. J Gen Microbiol 129, 1743–1813.
Williams, S. T., Goodfellow, M. & Alderson, G. (1989). Genus Streptomyces Waksman and Henrici 1943, 339AL. In Bergey's Manual of Systematic Bacteriology, vol. 4, pp. 2452–2492. Edited by S. T. Williams, M. E. Sharpe & J. G. Holt. Baltimore: Williams & Wilkins.
Xu, C., Wang, L., Cui, Q., Huang, Y., Liu, Z., Zhang, G. & Goodfellow, M. (2006). Neutrotolerant acidophilic Streptomyces species isolated from acidic soils in China: Streptomyces guanduensis sp. nov., Streptomyces paucisporeus sp. nov., Streptomyces rubidus sp. nov. and Streptomyces yanglinensis sp. nov. Int J Syst Evol Microbiol 56, 1109–1115.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |