Streptomyces halophytocola sp. nov., an endophytic ...

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International Journal of Systematic and Evolutionary Microbiology (2013), 63, 2770–2775

DOI 10.1099/ijs.0.047456-0

Streptomyces halophytocola sp. nov., an endophytic actinomycete isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. Sheng Qin,1 Guang-Kai Bian,1 Tomohiko Tamura,2 Yue-Ji Zhang,1 Wen-Di Zhang,1 Cheng-Liang Cao1 and Ji-Hong Jiang1 Correspondence Sheng Qin [email protected] Ji-Hong Jiang

1

The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, 221116, PR China

2

NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation, 2-5-8 Kazusakamatari, Kisarazu, Chiba 292-0818, Japan

[email protected]

A novel actinomycete, designated KLBMP 1284T, was isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. collected from the city of Nantong, Jiangsu Province, east China. The strain was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Analysis of the 16S rRNA gene sequence of strain KLBMP 1284T revealed that the strain formed a distinct clade within the phylogenetic tree based on 16S rRNA gene sequences and the highest sequence similarity (99.43 %) was to Streptomyces sulphureus NRRL B-1627T. 16S rRNA gene sequence similarity to other species of the genus Streptomyces was lower than 97 %. Based on DNA–DNA hybridization values and comparison of morphological and phenotypic data, KLBMP 1284T could be distinguished from the closest phylogenetically related species, Streptomyces sulphureus NRRL B-1627T. Thus, based on these data, it is evident that strain KLBMP 1284T represents a novel species of the genus Streptomyces, for which the name Streptomyces halophytocola sp. nov. is proposed. The type strain is KLBMP 1284T (5KCTC 19890T5NBRC 108770T).

The genus Streptomyces was proposed by Waksman & Henrici (1943) to accommodate actinobacteria that develop branched substrate mycelium and aerial hyphae, present LL-diaminopimedic acid without characteristic sugars in the cell wall (wall chemotype I; Lechevalier & Lechevalier, 1970). At the time of writing, the genus Streptomyces contains a large number of described species and more than 600 have validly published names (http:// www.bacterio.cict.fr/s/streptomycesa.html). Endophytic Streptomyces have been isolated from many higher plants in recent years and many of them have been demonstrated to have capacity to produce a vast array of secondary metabolites exhibiting a wide range of biological activity, such as antibiotic anti-tumour and anti-infection, plant growth promoters and enzymes (Strobel et al., 2004; Hasegawa et al., 2006; Qin et al., 2011). In an effort to discover novel actinomycetes from coastal halophytes in

eastern China, an endophytic actinomycete strain, KLBMP 1284T, was isolated from the halophyte Tamarix chinensis Lour. The present polyphasic study was designed to establish the taxonomic status of this strain.

Abbreviation: ISP, International Streptomyces Project.

Genomic DNA was extracted from the biomass preparations and PCR amplification and 16S rRNA gene sequencing was performed using procedures described by Li et al. (2007). The PCR product was purified and sequenced directly by an automated DNA sequencing system (ABI

The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain KLBMP 1284T is JQ819259. A supplementary table and a supplementary figure are available with the online version of this paper.

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Healthy samples of the halophyte Tamarix chinensis Lour., collected from Nantong coast (121u 09 38.960 E 32u 349 24.910 N), Jiangsu Province, east of China in October 2010, were used for isolation. In accordance with the surface-sterilized method described previously (Qin et al., 2009), the actinobacteria strains were isolated from the stems on modified tap water-yeast extract agar [3 % (w/v) NaCl added to this agar] (TWYE, Crawford et al., 1993) after a 3-week incubation at 28 uC. Strain KLBMP 1284T was picked, purified and then maintained on yeast extractmalt extract agar [International Streptomyces Project medium 2 (ISP 2); Shirling & Gottlieb, 1966] slants at 4 uC and as glycerol suspensions (20 %, v/v) at –80 uC.

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Streptomyces halophytocola sp. nov.

3730XL). The resultant sequences were first aligned via the BLAST search program of NCBI (http://blast.ncbi.nlm.nih. gov/). Phylogenetic neighbours were identified and pairwise 16S rRNA gene sequence similarities were calculated using the EzTaxon-e database (http://eztaxon-e.ezbiocloud. net/; Kim et al., 2012). Multiple alignments with sequences of the most closely related taxa and the construction of the phylogenetic trees were carried out using MEGA software version 5.0 (Tamura et al., 2011), and three treeing

algorithms, neighbour-joining (Saitou & Nei, 1987), maximum-likelihood (Felsenstein, 1981) and maximumparsimony (Kluge & Farris, 1969). The stability of the clades in the trees was appraised using a bootstrap value with 1000 repeats (Felsenstein, 1985). A distance matrix was generated using Kimura’s two-parameter model (Kimura, 1980). All positions containing gaps and missing data were eliminated from the dataset (complete deletion option). The G+C content of the genomic DNA was determined using

Streptomyces lilacinus NBRC 3944T (AB184819)

0.005

Streptomyces coerulescens NBRC 12758T (AB184122) Streptomyces abikoensis NBRC 13860T (AB184537) Streptomyces varsoviensis NRRL B-3589T (DQ026653) Streptomyces blastmyceticus NRRL B-5480T (AY999802)

93*

Streptomyces ardus NBRC 13430T (AB184864) Streptomyces cinnamoneus NBRC 12852T (AB184850)

67*

Streptomyces hiroshimensis NBRC 3839T (AB184802) Streptomyces lacticiproducens GIMN4.001T (GQ184344) Streptomyces morookaense LMG 20074T (AJ781349)

60* 55

Streptomyces thioluteus LMG 20253T (AJ781360) Streptomyces kasugaensis M338-M1T (AB024441) Streptomyces youssoufiensis X4T (FN421338) Streptomyces yatensis NBRC 101000T (AB249962)

65*

‘Streptomyces bingchenggensis’ BCW-1 (CP002047) Streptomyces sclerotialus DSM 43032T (AJ621608) Streptomyces ascomycinicus DSM 40822T (EU170121) T (DQ026662) Streptomyces ramulosus NRRL B-2714 -

Streptomyces platensis JCM 4662T (AB045882)

79*

Streptomyces fulvissimus NBRC 3717T (AB184787)

93*

Streptomyces variegatus LMG 20315T (AJ781371) 75*

Streptomyces spectabilis NBRC 13424T (AB184393)

99* 65* 55*

Streptomyces thermocarboxydus DSM 44293T(U94490) T (AJ494865) Streptomyces albogriseolus NRRL B-1305 -

100* Streptomyces viridodiastaticus NBRC 13106T (AB184317) Streptomyces halophytocola KLBMP 1284T (JQ819259 ) 100* Streptomyces sulphureus NRRL B-1627 -1627T (DQ442546)

64*

Streptomyces gibsonii NBRC 15415T (AB184663) 100* 98*

Streptomyces almquistii NBRC 13015T (AB184258) Streptomyces rangoonensis LMG 20295T (AJ781366) Streptomyces megasporus NBRC 14749T (AB184617) Streptomyces macrosporus NBRC 14748T (AB184616)

99*

Streptomyces radiopugnans R97T (DQ912930) Streptomyces fenghuangensis GIMN4.003T (GU356598) 85* Streptomyces nanhaiensis SCSIO 01248T (GQ871748) 69 Streptomyces thermolineatus DSM 41451T (Z68097) T (AB022868) Kitasatospora setae KM-6054 -

Fig. 1. Neighbour-joining tree based on 16S rRNA gene sequences showing the phylogenetic positions of strain KLBMP 1284T and some related species of the genus Streptomyces. Bootstrap values (expressed as percentages of 1000 replications) greater than 50 % are shown at branch points. Asterisks indicate branches of the trees that were also found using the maximumparsimony and maximum-likelihood tree-making algorithms. Bar, 0.005 substitutions per nucleotide position. http://ijs.sgmjournals.org

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the method of Mesbah et al. (1989). DNA–DNA hybridizations were performed using the fluorometric micro-well method (Ezaki et al., 1989; He et al., 2005). The morphology of the spore chain and the spore surface ornamentation of strain KLBMP 1284T were observed by light microscopy (SA3300-PL) and scanning electron microscopy (S-3400N; Hitachi) using cultures grown on ISP 2 agar for 21 days at 28 uC. Cultural characteristics were observed on a number of standard media (Table S1, available in IJSEM Online) after 2 weeks at 28 uC. Colours were determined by the methods described by Kelly (1964). The growth temperature (4, 10, 15, 20, 28, 37, 45 and 55 uC) and NaCl tolerance [0–15 % (w/v), at intervals of 1 %] was determined on ISP 2 agar at 28 uC for 14 days. The pH range for growth (pH 4.0–13.0, at intervals of 0.5 pH units) was determined using ISP 2 medium broth adjusted with 1 M HCl, 20 % (w/v) Na2CO3 and 1 M NaOH solution after sterilization, and incubated at 28 uC for 14 days. Carbon-source utilization was tested by using ISP 9 medium (Shirling & Gottlieb, 1966) supplemented with 1 % (final concentration) carbon sources. The utilization of amino acids as sole nitrogen sources was tested as described by Williams et al. (1983). Production of acid and other physiological and biochemical characteristics were tested by using the well-established procedures described by Gordon et al. (1974). Biomass for molecular systematic and chemotaxonomic studies was obtained by cultivation in shake flasks on a rotary shaker (150 r.p.m.) using Trypticase Soy Broth at 28 uC for 6 days. The isomer of diaminopimelic acid and whole-cell sugar compositions were analysed using TLC according to the procedures described by Lechevalier & Lechevalier (1980). Polar lipids were examined by twodimensional TLC and identified using the method of Minnikin et al. (1984). Menaquinones were extracted and purified as described by Collins et al. (1977) and analysed by HPLC (Groth et al., 1997). Fatty acids were analysed using the standard MIDI (Microbial Identification, Sherlock version 6.0) procedure (Sasser, 1990) and the Agilent GC 6850 gas chromatograph. The resulting fatty acid profiles were identified using the database library TSBA6 version 6.0. The almost-complete 16S rRNA gene sequence (1453 bp) of strain KLBMP 1284T was compared with sequences in the GenBank database. The results indicated that the isolate belonged to the genus Streptomyces. Strain KLBMP 1284T showed the highest 16S rRNA gene sequence similarity with Streptomyces sulphureus NRRL B-1627T (99.43 %). The 16S rRNA gene sequence similarity to other species of the genus Streptomyces was less than 97 %. It is evident from the phylogenetic tree (Fig. 1) that strain KLBMP 1284T was clustered to S. sulphureus NRRL B-1627T, and they formed a distinct subclade with a high bootstrap value of 100 % by neighbour-joining analysis. This relationship was also found in trees constructed using the maximumparsimony and maximum-likelihood algorithms. However, 2772

DNA–DNA hybridization revealed 46±1.4 % relatedness between strain KLBMP 1284T and S. sulphureus NRRL B1627T, which is below the commonly accepted threshold value for the phylogenetic definition of different species as recognized by Wayne et al. (1987). Morphological observation of a 21-day culture of strain KLBMP 1284T grown on ISP 2 medium revealed that strain KLBMP 1284T had the typical characteristics of members of the genus Streptomyces. The isolate formed a highly branched substrate mycelium and aerial hyphae which differentiated into spiral spore chains with smooth spores (Fig. 2). Growth of the organism was good on ISP 2, ISP 4, nutrient agar (NA) and potatoe-dextrose agar (PDA) media, moderate on ISP media 3 and 5, but poor on Czapek’s agar. The colour of the aerial mycelium was

(a)

(b)

Fig. 2. Scanning electron micrographs of strain KLBMP 1284T grown on ISP 2 medium for 21 days at 28 6C. Bars, 10 mm (a) and 5 mm (b).

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Streptomyces halophytocola sp. nov.

yellowish to orange–yellow and the substrate mycelium was yellowish-white to orange–yellow. Diffusible pigments were not produced on any of the media tested. (Table S1). Growth was observed at 15–37 uC, pH 6.0–9.0 and in presence of 0–10 % (w/v) NaCl (optimum, 3 %) on ISP 2 agar. Detailed physiological characteristics are presented in the species description and in Table 1. Strain KLBMP 1284T contained LL-diaminopimelic acid as the diamino acid. Whole-cell hydrolysates comprised arabinose, galactose and glucose. The major menaquinones were MK-9(H6) (67 %), MK-9(H8) (26 %) and MK-9(H4) (7 %). The major cellular fatty acids were anteiso-C15 : 0 (30.36 %), iso-C16 : 0 (16.52 %), C16 : 0 (10.65 %) and anteisoC17 : 0 (9.35 %).. A detailed fatty acid profile comparison of strain KLBMP 1284T with its nearest neighbour species, S. sulphureus NRRL B-1627T, is given in Table 2. The phospholipid profile of strain KLBMP 1284T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, phosphatidylethanolamine, an unknown aminophospholipid and several unknown glycolipids (Fig. S1). The G+C content of the DNA was 71.6 mol%. These chemotaxonomic data showed

that strain KLBMP 1284T should be assigned to the genus Streptomyces. Cultural characteristics of strain KLBMP 1284T clearly showed that it differed from the most closely related species S. sulphureus NRRL B-1627T (Table S1). Moreover, a combination of physiological and biochemical characteristics enabled strain KLBMP 1284T to be distinguished from its closest phylogenetic neighbour (Table 1). In addition, the phospholipid profile and the major fatty acid contents of strain KLBMP 1284T are clearly different from S. sulphureus NRRL B-1627T (Table 1-2). Together with the low DNA– DNA relatedness value, strain KLBMP 1284T represents a novel species of the genus Streptomyces, for which the name Streptomyces halophytocola sp. nov. is proposed. Description of Streptomyces halophytocola sp. nov. Streptomyces halophytocola (ha.lo.phy.to9co.la. Gr. n. hal, halos salt; Gr. n. phyton a plant; L. suff. -cola inhabitant, dweller; N.L. n. halophytocola inhabitant of a halophyte, Tamarix chinensis Lour.).

Table 1. Different characteristics of strain KLBMP 1284T and its closely related neighbour Streptomyces sulphureus NRRL B-1627T All data were obtained during this study under identical growth conditions. Both strains were positive for the assimilation of cellobiose, D-fructose, D-galactose, maltose, D-mannose, D-ribose, D-xylose, L-alanine, L-glycine and L-proline. Both strains degraded Tweens 20 and 40 and grew with 10 % NaCl. +, Positive or present; W, weakly positive; 2, negative or absent. Characteristic Aerial spore mass colour on TSA and NA media Spore-chain morphology Growth on Czapek’s medium Hydrolysis of: Casein Starch Tween 80 H2S production Growth at 15 uC Growth at pH 10.0 Assimilation of sole carbon sources Erythritol D-Glucose Raffinose D-Rhamnose Trehalose Acid produced from: Cellobiose Raffinose Assimilation of sole nitrogen sources L-Arginine L-Histidine Polar lipids*

KLBMP 1284T

S. sulphureus NRRL B-1627T

Orange–yellow Flexuous to spiral Poor

Grey–white Spiral Moderate

+ 2 + 2 2

2 + 2 + 2 +

+ + 2 + –

2 2 + 2 +

2 2

+

+ 2 DPG, PG, PE, PIM, PI, APL, 3GL

2 + DPG, PE, 2GL

W

W

*Polar lipids: DPG, diphosphatidylglycerol; PG, phosphatidylglycerol; PI, phosphatidylinositol; PIM, phosphatidylinositol mannosides; PE, phosphatidylethanolamine; APL, unknown aminophospholipid; GL, unknown glycolipid. http://ijs.sgmjournals.org

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Table 2. Fatty acid content (%) of strain KLBMP 1284T and its closely related neighbour Streptomyces sulphureus NRRL B-1627T

phosphatidylinositol, phosphatidylinositol mannosides, phosphatidylethanolamine, an unknown aminophospholipid and several unknown glycolipids.

All data are from this study. Values are percentages of total fatty acids; fatty acids amounting to less than 0.5 % in both species are not shown. 2, Not detected.

The type strain KLBMP 1284T (5KCTC 19890T5NBRC 108770T) was isolated from surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. collected from the city of Nantong, Jiangsu Province, east China. The DNA G+C content of the type strain is 71.6 mol%.

Fatty acid C14 : 0 C16 : 0 C17 : 0 C18 : 0 C16 : 1v5c C17 : 1v8c C18 : 1v9c iso-C14 : 0 iso-C15 : 0 anteiso-C15 : 0 anteiso-C15 : 0 A iso-C16 : 0 iso-C16 : 1 H iso-C17 : 0 cyclo C17 : 0 anteiso-C17 : 0 anteiso-C17 : 1v9c Summed features* 1 3 5 8 9

KLBMP 1284T

S. sulphureus NRRL B-1627T

0.93 10.65 0.78 2.19 2 2 1.86 2 7.14 30.36 2.58 16.52 2 2.05 2.45 9.35 0.65

1.23 8.67 0.90 2 1.16 2 2 6.45 16.41 24.55 2 21.03 0.55 3.25 3.95 5.39 0.53

Acknowledgements

6.57 1.43 2.35 2 0.88

2 2.01 2 0.55 2

Ezaki, T., Hashimoto, Y. & Yabuuchi, E. (1989). Fluorometric

*Summed features represent groups of two or three fatty acids that cannot be separated by GC with the MIDI system. Summed feature 1comprised C15 : 1 iso H/C13 : 0 3-OH; summed feature 3 comprised C16 : 1v7c /C16 : 1v6c; summed feature 5 comprised C18 : 2v6, 9c /C18 : 0 ante; summed feature 8 comprised C18 : 1v7c /C18 : 1v6c; summed feature 9 comprised C17 : 1 iso v9c /C16 : 0 10-methyl.

Aerobic, Gram-stain-positive actinomycete that develops well-branched yellowish-white to orange–yellow substrate mycelium and yellowish to orange–yellow aerial mycelium. Produces long spiral spore chains with smooth spores. No diffusible pigment is formed on any of the tested media. Growth occurs at 15–37 uC (optimum, 28 uC). Optimal growth occurs at pH 7.0–7.5. NaCl tolerance on ISP 2 agar medium is 10 % (w/v) (optimum, 3 %). No reduction of nitrate to nitrite is observed. Degrades casein and Tweens 20, 40 and 80, but not starch, cellulose or gelatin. Most sugars can be utilized as sole carbon sources for growth, but not Darabinose, inositol, lactose, raffinose, D-sorbitol or trehalose. Acid is produced on D-galactose, D-glucose, maltose and xylose. The major cellular fatty acids are anteiso-C15 : 0, isoC16 : 0, C16 : 0 and anteiso-C17 : 0. The major menaquinones are MK-9(H6), MK-9(H8) and MK-9(H4). The polar lipid profile consists of diphosphatidylglycerol, phosphatidylglycerol, 2774

This research was partially supported by National Natural Science Foundation of China (31000005, 31101502, 31100009), the Program of Natural Science Foundation of the Jiangsu Higher Education Institutions of China (10 kJB180008, 11 kJD210002), the project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and Natural Science Foundation by Xuzhou City (No. XZZD1004).

References Collins, M. D., Pirouz, T., Goodfellow, M. & Minnikin, D. E. (1977).

Distribution of menaquinones in actinomycetes and corynebacteria. J Gen Microbiol 100, 221–230. Crawford, D. L., Lynch, J. M., Whipps, J. M. & Ousley, M. A. (1993).

Isolation and characterization of actinomycete antagonists of a fungal root pathogen. Appl Environ Microbiol 59, 3899–3905. 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, 224–229. Felsenstein, J. (1981). Evolutionary trees from DNA sequences: a maximum likelihood approach. J Mol Evol 17, 368–376. Felsenstein, J. (1985). Confidence limits on phylogenies: an approach

using the bootstrap. Evolution 39, 783–791. Gordon, R. E., Barnett, D. A., Handerhan, J. E. & Pang, C. H.-N. (1974). Nocardia coeliaca, Nocardia autotrophica, and the nocardin

strain. Int J Syst Bacteriol 24, 54–63. Groth, I., Schumann, P., Rainey, F. A., Martin, K., Schuetze, B. & Augsten, K. (1997). Demetria terragena gen. nov., sp. nov., a new

genus of actinomycetes isolated from compost soil. Int J Syst Bacteriol 47, 1129–1133. Hasegawa, S., Meguro, A., Shimizu, M., Nishimura, T. & Kunoh, H. (2006). Endophytic actinomycetes and their interactions with host

plants. Actinomycetologica 20, 72–81. He, L., Li, W., Huang, Y., Wang, L., Liu, Z., Lanoot, B., Vancanneyt, M. & Swings, J. (2005). Streptomyces jietaisiensis sp. nov., isolated from

soil in northern China. Int J Syst Evol Microbiol 55, 1939–1944. Kelly, K. L. (1964). Inter-Society Color Council-National Bureau of

standards color-name charts illustrated with centroid colors published in US. Washington, DC: US Government Printing Office. Kim, O. S., Cho, Y. J., Lee, K., Yoon, S. H., Kim, M., Na, H., Park, S. C., Jeon, Y. S., Lee, J. H. & other authors (2012). Introducing EzTaxon-e:

a prokaryotic 16S rRNA gene sequence database with phylotypes that represent uncultured species. Int J Syst Evol Microbiol 62, 716–721. Kimura, M. (1980). A simple method for estimating evolutionary rates

of base substitutions through comparative studies of nucleotide sequences. J Mol Evol 16, 111–120.

Downloaded from www.microbiologyresearch.org by International Journal of Systematic and Evolutionary Microbiology 63 IP: 54.210.20.124 On: Wed, 28 Oct 2015 22:45:17

Streptomyces halophytocola sp. nov. Kluge, A. G. & Farris, F. S. (1969). Quantitative phyletics and the

evolution of anurans. Syst Zool 18, 1–32. Lechevalier, M. P. & Lechevalier, H. (1970). Chemical composition as

plant-associated endophytic Biotechnol 89, 457–473.

actinobacteria.

Appl

Microbiol

a criterion in the classification of aerobic actinomycetes. Int J Syst Bacteriol 20, 435–443.

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

Lechevalier, M. P. & Lechevalier, H. A. (1980). The chemotaxonomy

Sasser, M. (1990). Identification of Bacteria by Gas Chromatography

of actinomycetes. In Actinomycete Taxonomy, pp. 22–291. Edited by A. Dietz & D. W. Thayer. Arlington, VA: Society for Industrial Microbiology.

of Cellular Fatty Acids, MIDI Technical Note 101. Newark, DE: MIDI Inc.

Li, W. J., Xu, P., Schumann, P., Zhang, Y. Q., Pukall, R., Xu, L. H., Stackebrandt, E. & Jiang, C. L. (2007). Georgenia ruanii sp. nov., a

novel actinobacterium isolated from forest soil in Yunnan (China), and emended description of the genus Georgenia. Int J Syst Evol Microbiol 57, 1424–1428. Mesbah, M., Premachandran, U. & Whitman, W. B. (1989). Precise

Shirling, E. B. & Gottlieb, D. (1966). Methods for characterization of

Streptomyces species. Int J Syst Bacteriol 16, 313–340. Strobel, G., Daisy, B., Castillo, U. & Harper, J. (2004). Natural

products from endophytic microorganisms. J Nat Prod 67, 257–268. Tamura, K., Peterson, D., Peterson, N., Stecher, G., Nei, M. & Kumar, S. (2011). MEGA5: molecular evolutionary genetics analysis using

measurement of the G+C content of deoxyribonucleic acid by highperformance liquid chromatography. Int J Syst Bacteriol 39, 159–167.

maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 28, 2731–2739.

Minnikin, D. E., O’Donnell, A. G., Goodfellow, M., Alderson, G., Athalye, M., Schaal, A. & Parlett, J. K. (1984). An integrated

Waksman, S. A. & Henrici, A. T. (1943). The nomenclature and

procedure for the extraction of bacterial isoprenoid quinones and polar lipids. J Microbiol Methods 2, 233–241.

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 Systematic

Qin, S., Li, J., Chen, H. H., Zhao, G. Z., Zhu, W. Y., Jiang, C. L., Xu, L. H. & Li, W. J. (2009). Isolation, diversity, and antimicrobial activity of

rare actinobacteria from medicinal plants of tropical rain forests in Xishuangbanna, China. Appl Environ Microbiol 75, 6176–6186.

classification of the actinomycetes. J Bacteriol 46, 337–341.

Bacteriology. Report of the ad hoc committee on reconciliation of approaches to bacterial systematics. Int J Syst Bacteriol 37, 463–464.

Qin, S., Xing, K., Jiang, J. H., Xu, L. H. & Li, W. J. (2011). Biodiversity,

Williams, S. T., Goodfellow, M., Alderson, G., Wellington, E. M. H., Sneath, P. H. A. & Sackin, M. J. (1983). Numerical classification of

bioactive natural products and biotechnological potential of

Streptomyces and related genera. J Gen Microbiol 129, 1743–1813.

http://ijs.sgmjournals.org

Downloaded from www.microbiologyresearch.org by IP: 54.210.20.124 On: Wed, 28 Oct 2015 22:45:17

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