Introduction

Waksman and Henrici proposed the formation of the genus Streptomyces belonging to the family Streptomycetaceae with the purpose of accommodating aerobic, Gram-positive and spore-forming actinomycetes.1 At present, the genus comprises 611 species with validly published names, without considering homotypic and heterotypic synonyms (http://www.dsmz.de/bacterial-diversity/prokaryotic-nomenclature-up-to-date, last accessed 30 August 2016), qualifying it as the largest genus in the domain Bacteria. It is becoming progressively obvious that the taxonomic and metabolic diversity exhibited by streptomycetes is extraordinary, as novel and putatively new Streptomyces species are being continuously isolated from underexplored habitats, demonstrating that this genus is a valuable resource for new bioactive compounds.2, 3

Mangroves occur along tropical and subtropical estuaries where fresh water and sea water mix together. Mangrove forests are vital sources for the discovery of novel actinomycetes, given that the major environmental determinant of the microbial community structure is salinity.3, 4 The continual changes in tidal gradient and salinity in the mangrove environment are considered to be drivers for microbial metabolic pathway diversity and can bring about the synthesis of atypical metabolites. This has encouraged the exploration of mangroves to identify novel microorganisms.5 Several researchers have isolated novel streptomycetes from mangroves, such as Streptomyces pluripotens,5 Streptomyces qinglanensis,6 Streptomyces sanyensis,7, Streptomyces xiamenensis3 and Streptomyces avicenniae.8 Earlier, we described Streptomyces sundarbansensis as the first validly described actinobacterium from the Sundarbans,9 the largest mangrove forest in the world. Very recently, another research group explored this region for novel actinomycetes.10

Previously, we reported strain MS 3/20T that expresses antimicrobial activity against Gram-positive and Gram-negative bacteria, molds, yeast and various multiple-drug resistant bacteria, including methicillin-resistant Staphylococcus aureus. The highly stable, active principle was purified, and a single compound was shown to possess broad-spectrum activity. Molecular characterization identified the active compound as a lipid.11 We now present evidence that strain MS 3/20T should be recognized as a new species that we propose be named Streptomyces euryhalinus MS 3/20T.

Materials and methods

Isolation and cultivation

Strain MS 3/20T was isolated from sediment of the Lothian Island of the Sundarbans mangrove forest, India (Lat. 20°50′N, Long. 88°19′E), by serial dilution and plating followed by incubation at 28 °C for 4 days on an enrichment medium reported earlier.11 The strain was preserved in −80 °C as well as −20 °C freezers as glycerol stocks (10–15%) after its isolation. The strain was also preserved by lyophilization. Working cultures of strain MS 3/20T for morphological, physiological and biochemical studies were maintained at 0–4 °C. Biomass for molecular and chemotaxonomic analysis was obtained by culturing the strain on a modified medium described by Saha et al.11 consisting of 2.0 g starch, 2.0 g glucose, 2.0 g soybean meal, 0.5 g yeast extract, 0.25 g NaCl, 0.32 g CaCO3, 0.005 g CuSO4, 0.005 g MnCl2, 0.005 g ZnSO4, 500 ml distilled water and 500 ml artificial sea water (pH 7.2) and incubating at 28 °C for 4 days. Strain MS 3/20T was deposited in the Chinese Centre for Industrial Culture Collection (CICC 11032T) and Leibniz Institute DSMZ–German Collection of Microorganisms and Cell Cultures (DSM 103378T).

The reference strains Streptomyces variabilis NRRL B-3984T, Streptomyces erythrogriseus NRRL B-3808T, Streptomyces griseoincarnatus NRRL B-5313T, Streptomyces labedae NRRL B-5616T, Streptomyces griseorubens NRRL B-3982T, Streptomyces althioticus NRRL B-3981T, Streptomyces griseoflavus NRRL B-5312T, Streptomyces matensis NRRL B-2576T, Streptomyces viridochromogenes NRRL B-1511T, Streptomyces albogriseolus NRRL B-1305T and Streptomyces paradoxus NRRL B-3457T were obtained as gifts from the ARS Culture Collection (NRRL), United States Department of Agriculture (Peoria, IL, USA) for comparative studies and were cultivated on International Streptomyces Project (ISP) 2 medium at 28 °C.

Phenotypic characterization

Spore chain morphology and spore surface ornamentation were studied by light (Leica DM750, Leica Microsystems, Buffalo Grove, IL, USA) and scanning electron (Jeol JSM-6700F, Jeol, Tokyo, Japan) microscopy following growth on ISP 2 medium at 28 °C for 14 days.12 Colors of the aerial and substrate mycelia were determined on different ISP media (ISP 2, ISP 3, ISP 4, ISP 5 and ISP 6) by incubating at 28 °C for 2 to 3 weeks.12 Tests for carbon source utilization were performed by supplementing a 1% carbon source in ISP 9 medium, and melanin production was assessed in ISP 6 medium following the protocols of Shirling and Gottlieb.12 Utilization of amino acids as nitrogen sources, degradation of starch and gelatin, nitrate reduction and H2S production were tested according to Williams et al.13 Susceptibility/resistance to various antibiotics was measured by the disk diffusion plate technique. The effects of temperatures ranging from 15 to 45 °C (15–19 °C at intervals of 2 °C, 20–40 °C at intervals of 1 °C and 41–45 °C at intervals of 2 °C) on growth were observed visually for 14 days on ISP 2 medium. Growth over a pH range (1–12 at intervals of 0.5 units) and at different NaCl concentrations (0–25% w/v, at an increment of 1%) was recorded spectrophotometrically (OD600 nm) for 14 days on ISP 2 medium. Catalase activity was tested on modified Bennett’s agar medium.13 To test oxidase activity, MS 3/20T was grown in modified Bennett’s agar medium, and the color change was observed on oxidase strips (Sigma-Aldrich, St Louis, MO, USA). Esculin, L-tyrosine degradation and urea decomposition were observed as per Gordon et al.14 Physiological characteristics were determined thrice in duplicate sets.

Chemotaxonomic characterization

Analyses of whole-cell sugars and isomers of diaminopimelic acid in MS 3/20T peptidoglycan were performed using dried cell mass and identified by TLC following the protocol of Staneck and Roberts.15 Respiratory quinones were identified by the China Center of Industrial Culture Collection (Beijing, China), applying FMIC-QO01-008 Analytical Method for Microbial Quinone Compounds.16, 17 Polar lipid analysis was performed by Microbial Culture Collection (MCC), Pune, India. Polar lipids were extracted with methanol, chloroform and saline solution (2:1:0.8, v/v).18, 19 The lipids were separated by two-dimensional TLC20 and identified using the spraying agents ninhydrin, α-naphthol, Dragendorff, molybdenum blue and molybdophosphoric acid. Analysis of cellular fatty acids21, 22 was carried out by Royal Life Sciences (affiliated to MIDI Sherlock), Secundrabad, India. Cell mass at 40 mg was saponified, methylated and extracted to acquire fatty acid methyl esters. Separation and identification were carried out via the application of GC and the Sherlock Microbial Identification System (MIDI, Microbial ID, Newark, DE, USA). The DNA G+C content (mol%) was estimated by a thermal denaturation method following Marmur and Doty.23

16S rRNA gene sequencing and phylogenetic analysis

PCR amplification of the 16S ribosomal RNA (rRNA) gene of strain MS 3/20T and its sequencing was carried out by the DSMZ Identification Service (Braunschweig, Germany).24 Pairwise sequence similarity of the 16S rRNA gene sequence was determined on the EzTaxon-e-server (http://eztaxon-e.ezbiocloud.net/; last accessed 30 August 2016) to identify the close relatives of strain MS 3/20T.25 Reference strains for phylogenetic analysis were selected from the top hits of this determination. The 1503-bp 16S rRNA gene sequence of strain MS 3/20T was aligned with the sequences of closely related Streptomyces type strains using the CLUSTAL W program26 in Molecular Evolutionary Genetics Analysis (MEGA) 6 software.27 The neighbor-joining28 algorithm was used to construct the phylogenetic tree using MEGA 6.27 Kimura’s two-parameter model29 was used to estimate the evolutionary distance matrix. Bootstrap analysis was performed with 1000 resamplings.30

DNA–DNA hybridization

DNA–DNA reassociation was performed thrice for species delineation by the dot blot method31 with digoxigenin-labeled DNA using a DIG High Prime DNA detection kit (Roche Applied Science, Benzberg, Germany) following the manufacturer’s instructions. Eleven strains that demonstrated the highest 16S rRNA similarities were selected for the DNA–DNA relatedness study. Dot intensities were measured using ImageJ software (http://rsb.info.nih.gov/ij/index.html); self-hybridization value was considered 100%.

RAPD-PCR amplification

Random amplified polymorphic DNA (RAPD-PCR) amplification and selection of primers were performed following Lee et al.32 Three primers, AM50, AM62 and 70-34, were selected for the RAPD-PCR study. PCR amplification was carried out twice. The amplified PCR products were analyzed on an agarose gel after staining with ethidium bromide solution, and images were captured on an E-Gel imager (Thermo Fisher Scientific, Waltham, MA, USA).

MALDI-TOF/MS

Strains were grown for 3–4 days in ISP 2 medium to obtain the matrix-assisted laser desorption/ionization–time-of-flight/mass spectrometry (MALDI-TOF/MS) profiles of whole-cell proteins from strain MS 3/20T and other type strains. Whole-cell proteins from actively growing cultures were extracted using ethanol, formic acid and acetonitrile. The extract was analyzed on an Autoflex TOF/TOF mass spectrometer (Bruker Daltonik GmbH, Bremen, Germany), and MALDI Biotyper software 3.0 (Bruker Daltonik GmbH) was used to visualize the mass spectra. This experiment was outsourced to MCC, Pune, India.

Nucleotide sequence accession number

The GenBank/EMBL/DDBJ accession number of the 16S rRNA gene sequence of strain MS 3/20T is KR827683.

Results and Discussion

The morphological characteristics of strain MS 3/20T were typical of the genus Streptomyces. Scanning electron microscopy image at high (Figure 1) and low magnification (Supplementary Figures S4a–d) as well as light microscopy images under oil immersion (Supplementary Figures S4e and f) of strain MS 3/20T grown on ISP 2 medium clearly showed long-chain spiny-surfaced spores in a retinaculum-apertum arrangement. The colors of the aerial and substrate mycelia of the strain on different ISP media are shown in Supplementary Table S1. The strain showed positive activity for catalase, oxidase and urea decomposition. It showed negative results for nitrate reduction, gelatin liquefaction and melanin production. The strain was observed to be positive for esculin and starch degradation but negative for L-tyrosine degradation and hydrogen sulfide production. It demonstrated resistance to penicillin and susceptibility to ampicillin, polymixin B and neomycin. Arabinose, sucrose, lactose and sodium citrate were utilized by the strain as sole carbon sources, whereas sorbitol and sodium acetate were not utilized. The strain utilized tyrosine, leucine, isoleucine, valine, tryptophan and glutamine as sole amino acid sources. Growth was recorded between pH 5.0 to 9.0 and at temperatures between 24 and 35 °C. A whole-cell hydrolysate of the strain demonstrated the presence of LL-diaminopimelic acid and galactose. The polar lipids: glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine (Dragendorff positive), unidentified phospholipid and unidentified amino lipid were observed in strain MS 3/20T (Supplementary Figure S1). The menaquinones identified were MK-9(H8): 52.3%, MK-9(H6): 35.6%, MK-9(H4): 8.5% and MK-9(H2): 3.6%. The major cellular fatty acids present were anteiso-C15:0 (17.53%), iso-C16:0 (23.89%) and anteiso-C17:0 (10.29%) (Supplementary Table S2). The DNA G+C content of strain MS 3/20T was estimated at 77.3 mol%. These chemotaxonomic data revealed strain MS 3/20T to be a member of the genus Streptomyces.

Figure 1
figure 1

Scanning electron micrograph of strain MS 3/20T grown on International Streptomyces Project 2 medium for 14 days at 28 °C.

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The 16S rRNA gene sequence (KR827683) affiliated strain MS 3/20T with the genus Streptomyces. The gene sequence showed 100% similarity with S. variabilis NBRC 12825T (AB184884), S. erythrogriseus LMG 19406T (AJ781328), S. griseoincarnatus LMG 19316T (AJ781321) and S. labedae NBRC 15864T (AB184704), thus creating ambiguity in the initial identity of MS 3/20T. The limitations of the 16S rRNA gene sequence data alone for species delineation within the genus Streptomyces due to intraspecific variation, intragenomic heterogeneity, insufficient resolution capacity and inconsistency with DNA–DNA relatedness have been highlighted by several authors.33, 34, 35, 36, 37 According to Labeda et al.,38 it is impossible to recommend a definite16S rRNA gene sequence similarity value at which an unidentified actinobacterium may or may not be a novel species of the genus Streptomyces.

Other close relatives sharing more than 99% 16S rRNA gene sequence similarity were S. griseorubens NBRC 12780T (AB184139) (99.73%), S. althioticus NRRL B-3981T (AY999791) (99.52%), S. griseoflavus LMG 19344T (AJ781322) (99.45%), S. matensis NBRC 12889T (AB184221) (99.45%), S. viridochromogenes NBRC 3113T (AB184728) (99.11%), S. albogriseolus NRRL B-1305T (AJ494865) (99.05%), S. heliomycini NBRC 15899T (AB184712) (99.04%), S. paradoxus NBRC 14887T (AB184628) (99.04%) and S. viridodiastaticus NBRC 13106T (AB184317) (99.04%). The neighbor-joining -phylogenetic tree (Figure 2) further confirmed that strain MS 3/20T belongs to the genus Streptomyces; MS 3/20T clustered with S. griseoincarnatus LMG 19316T (AJ781321), S. erythrogriseus LMG 19406T (AJ781328), S. variabilis NBRC 12825T (AB184884) and S. labedae NBRC 15864T (AB184704), thus reinforcing the close relationship among these five strains. Considering the insufficient resolution capacity of the 16S rRNA molecule, Kämpfer et al.36 cautioned that within the Streptomyces genus, the conclusions derived from simple treeing methods (such as the neighbor-joining algorithm) should be considered with prudence, as a ‘tree is only a visual aid to place a novel species in its approximate neighborhood.’

Figure 2
figure 2

Neighbor-joining phylogenetic tree based on 16S ribosomal RNA (rRNA) gene sequences showing the position of Streptomyces euryhalinus MS 3/20T within the genus Streptomyces. Numbers at nodes indicate levels of bootstrap support (percentages of 1000 replicates); only values of >50% are shown. GenBank accession numbers are given in parentheses. Bar, 0.002 nucleotide substitutions per site.

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Despite high 16S rRNA gene sequence similarity with other Streptomyces species, strain MS 3/20T showed maximum DNA–DNA relatedness (53.8±3.5%) with S. griseoflavus NRRL B-5312T, significantly lower than the general 70% cutoff value for species differentiation39 and the 80% value recommended for recognition of a novel species in the Streptomyces genus.36 The DNA–DNA reassociation values of strain MS 3/20T with the other phylogenetically close type strains varied between 27.2 and 35.5% (Table 1). This result clearly indicated that strain MS 3/20T is different from the reference type strains and is a new species.

Table 1 Values of DNA–DNA hybridization between strain MS 3/20T (accession no. KR827683) and its phylogenetically close relatives
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Fingerprinting techniques like RAPD can also be applied for the differentiation of species within a genus.40 Consequentially, RAPD was performed to establish the differences between strain MS 3/20T and other phylogenetically close neighbors that showed dissimilarities in DNA–DNA hybridization. The banding pattern of the randomly amplified DNA of strain MS 3/20T exhibited recognizable differences compared with the patterns of its relatives (Supplementary Figure S2).

MALDI-TOF/MS is a recent technique applied for bacterial identification and is an effective tool for the differentiation of closely related species.41 The MALDI-TOF/MS spectrum of whole-cell proteins of strain from MS 3/20T was distinct from the corresponding spectra of other reference strains. Whole-cell proteins of strain MS 3/20T displayed peaks at regions (m/z values) 2700, 3900, 4600, 5000, 5300, 7200, 8200, 8800 and 9400 (Supplementary Figure S3). A few of these m/z values were also present in other type strains, but they never occurred simultaneously. Peaks at regions (m/z values) 3300, 3600, 4100, 4800, 4900, 5400, 5800, 6600, 7300, 7400, 7700, 11 000, 12 000, 13 000, 15 000 and 18 000 were absent in strain MS 3/20T but were present in other phylogenetically related strains (Supplementary Figure S3). In the genus Streptomyces, MALDI-TOF/MS data played an important role during the reclassification of Streptomyces spheroides and Streptomyces laceyi.42 Thus, the RAPD-PCR banding pattern (Supplementary Figure S2) and MALDI-TOF/MS peak profile (Supplementary Figure S3) of strain MS 3/20T demonstrated substantial disparities when compared with the corresponding data obtained from the closely related type strains, confirming the DNA–DNA hybridization results and further justifying strain MS 3/20T as a novel species in the genus Streptomyces.

The morphological, physiological and biochemical characteristics of strain MS 3/20T demonstrated 29 differentiating characteristics in total when compared with 11 phylogenetically close neighbors (Table 2). Out of the 29 characteristics, MS 3/20T exhibited a minimum of 11 differentiating characteristics when compared with S. griseoflavus NRRL B-5312T and a maximum of 18 distinguishing characteristics when compared with S. erythrogriseus NRRL B-3808T and S. griseoincarnatus NRRL B-5313T. Strain MS 3/20T exhibited growth in media containing NaCl (range 0–20%), and this was the most vital discriminating property not observed for any other reference strain. Strain MS 3/20T was different in many aspects from the four closely related species showing 100% similarity in the 16S rRNA gene sequence. The spore chain arrangement of strain MS 3/20T was retinaculum-apertum, whereas the other four strains showed flexuous to straight arrangement (Table 2). The aerial mass color of strain MS 3/20T cultivated on ISP 2 medium was yellowish brown to red, whereas that of S. variabilis NRRL B-3984T, S. erythrogriseus NRRL B-3808T and S. labedae NRRL B-5616T was gray to yellow, and that of S. griseoincarnatus NRRL B-5313T was red. On ISP 3 medium strain MS 3/20T produced gray- to brown-colored aerial mycelia that was different from gray-colored aerial mass of S. variabilis NRRL B-3984T and S. labedae NRRL B-5616T, gray- to yellow-colored aerial mass of S. erythrogriseus NRRL B-3808T and brown- to red-colored aerial mycelia of S. griseoincarnatus NRRL B-5313T. Yellow- to brown-colored aerial mycelia was observed when strain MS 3/20T was grown on ISP 4 medium, whereas S. variabilis NRRL B-3984T and S. labedae NRRL B-5616T displayed yellow- to gray-colored aerial mycelia, S. erythrogriseus NRRL B-3808T presented yellow-colored aerial mass and S. griseoincarnatus NRRL B-5313T yielded brown-colored aerial mass. The aerial mass color of strain MS 3/20T grown on ISP 5 medium was yellow to brown that was dissimilar from S. erythrogriseus NRRL B-3808T and S. labedae NRRL B-5616T (gray to brown), S. variabilis NRRL B-3984T (gray to yellow) and S. griseoincarnatus NRRL B-5313T (brown to red). When cultivated on ISP 6 medium, strain MS 3/20T and S. griseoincarnatus NRRL B-5313T produced yellow- to brown-colored aerial mycelium, whereas S. variabilis NRRL B-3984T, S. erythrogriseus NRRL B-3808T and S. labedae NRRL B-5616T produced gray-, brown-, brown- to gray-colored aerial masses, respectively. These dissimilarities are indicated in (Supplementary Table S1).

Table 2 Differential phenotypic characteristics of strain MS 3/20T and its phylogenetically close relatives of the genus Streptomyces
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The color of the substrate mycelium produced by strain MS 3/20T on ISP 2 medium was yellow to brown that was similar to S. erythrogriseus NRRL B-3808T but different from S. variabilis NRRL B-3984T (brown), S. griseoincarnatus NRRL B-5313T (brown to red) and S. labedae NRRL B-5616T (brown to blue). Strain MS 3/20T produced yellow- to brown-colored substrate mycelium on ISP 3 medium that was similar to S. erythrogriseus NRRL B-3808T but different from S. variabilis NRRL B-3984T that displayed yellow- to gray-colored, S. griseoincarnatus NRRL B-5313T that presented gray- to red-colored and S. labedae NRRL B-5616T that showed brown- to red-colored substrate mycelia. Strain MS 3/20T produced gray- to brown-colored substrate mycelium on ISP4 medium, whereas S. variabilis NRRL B-3984T, S. erythrogriseus NRRL B-3808T, S. griseoincarnatus NRRL B-5313T and S. labedae NRRL B-5616T produced brown, brown to pink, gray to yellow and yellow to brown-colored substrate mycelia, respectively. Yellowish brown to blue-colored substrate mycelium of strain MS 3/20T was observed on ISP 5 medium, whereas S. variabilis NRRL B-3984T produced brown-colored, S. erythrogriseus NRRL B-3808T exhibited gray- to brown-colored, S. griseoincarnatus NRRL B-5313T displayed red-colored and S. labedae NRRL B-5616T presented gray- to brown-colored substrate mycelia. Strain MS 3/20T produced brown- to red-colored substrate mycelium on ISP 6 media that was unlike S. variabilis NRRL B-3984T (gray to blue), S. erythrogriseus NRRL B-3808T (gray to brown), S. griseoincarnatus NRRL B-5313T (red) and S. labedae NRRL B-5616T (brown to blue). These dissimilarities are highlighted in Supplementary Table S1. The distinctive fatty acid, antesio C17:1 was present in strain MS 3/20T (3.28%) but absent in the other four closely related strains (Supplementary Table S2). Strain MS 3/20T grew in presence of sodium chloride 0–20% concentration, whereas the other four closely related strains failed to do so. Similarly, arabinose was utilized by strain MS 3/20T as sole carbon source, whereas the other four strains could not. Strain MS 3/20T was susceptible to ampicillin, whereas the four closely related strains were resistant to it. Furthermore, strain MS 3/20T was positive for oxidase activity, whereas the other four strains were negative.

In conclusion, all data obtained from the experiments (DNA–DNA hybridization, RAPD banding pattern and MALDI-TOF/MS profile as well as morphological, physiological and biochemical characteristics) affiliated strain MS 3/20T with the genus Streptomyces as a novel species for which the name Streptomyces euryhalinus MS 3/20T sp. nov. is proposed.

Description of Streptomyces euryhalinus sp. nov.

Streptomyces euryhalinus (eu.ry.ha’linus Gr. adj. eurus, broad; Gr. n. halos, salt; L. suff.-inus suffix implying sense of belonging to; N.L. masc. adj. euryhalinus, living in a broad range of salinity).

Cells are Gram-positive, aerobic, non-motile. Spores are spiny, forming a retinaculum-apertum long chain. Grows luxuriantly on ISP 2, ISP 3, ISP 4, ISP 5 and ISP 6 media. Aerial mycelium is yellowish brown to red on ISP 2 medium, gray to brown on IPS 3 medium and yellow to brown on ISP 4, ISP 5 and ISP 6 media. Substrate mycelium color is yellow to brown on ISP 2 and ISP 3 media, gray to brown on ISP 4 medium, yellow-brown to blue on ISP 5 medium, brown to red on ISP 6 medium. Diffusible melanin pigment not produced in any ISP medium. Cell wall contains LL-DAP, and whole-cell hydrolysate shows the presence of galactose. Polar lipids present are glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and unidentified amino lipid. Major fatty acids are anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The predominant menaquinones are MK-9(H6) and MK-9(H8), whereas MK-9(H4) and MK-9(H2) are minor components. Positive for catalase, oxidase and urea decomposition. Negative for nitrate reduction, gelatin liquefaction and hydrogen sulfide production. Positive for esculin and starch degradation and negative for L-tyrosine degradation. Resistant to penicillin (10 units) and susceptible to ampicillin (10 μg), polymixin B (300 units), gentamicin (30 μg), tetracycline (30 μg), streptomycin (10 μg), kanamycin (30 μg), carbenicillin (100 μg), oleandomycin (15 μg), lincomycin (15 μg), vancomycin (30 μg), chloramphenicol (30 μg) and neomycin (30 μg). Utilizes arabinose, sucrose, lactose, sodium citrate, starch, mannose, xylose, inositol, cellobiose, trehalose, galactose, maltose and mannitol as sole carbon sources, but does not utilize sorbitol, sodium acetate and sodium succinate. Utilizes alanine, arginine, asparagine, glutamine, lysine, methionine, proline, threonine, histidine, tyrosine, leucine, isoleucine, valine, tryptophan and glutamine as sole amino acid sources, but does not utilize cystine. Grows in the presence of 0 to 20% NaCl (optimum 5%) at a temperature range between 24 and 35 °C (optimum 28 °C) and at a pH range between 5.0 and 9.0 (optimum 7.2–7.5).

The type strain MS 3/20T (=CICC 11032T =DSM 103378T) was isolated from sediment of the Sundarbans mangrove forest in India. The genomic DNA G+C content of the type strain is 77.3 mol%.