Marinobacter azerbaijanicus sp. nov., a moderately halophilic bacterium from Urmia Lake, Iran.

A novel moderately halophilic, Gram-stain-negative and facultatively anaerobic bacterium, designated as strain TBZ242T, was isolated from water of Urmia Lake in the Azerbaijan region of Iran. The cells were found to be rod-shaped and motile by a single polar flagellum, producing circular and yellowish colonies. The strain could grow in the presence of 0.5-10 % (w/v) NaCl (optimum, 2.5-5 %). The temperature and pH ranges for growth were 15-45 °C (optimum 30 °C) and pH 7.0-11.0 (optimum pH 8.0) on marine agar. The 16S rRNA gene sequence analysis revealed that strain TBZ242T belonged to the genus Marinobacter, showing the highest similarities to Marinobacter algicola DG893T (98.8 %), Marinobacter vulgaris F01T (98.8 %), Marinobacter salarius R9SW1T (98.5 %), Marinobacter panjinensis PJ-16T (98.4 %), Marinobacter orientalis W62T (98.0 %) and Marinobacter denitrificans JB2H27T (98.0 %). The 16S rRNA and core-genome phylogenetic trees showed that strain TBZ242T formed a distinct branch, closely related to a subclade accommodating M. vulgaris, M. orientalis, M. panjinensis, M. denitrificans, M. algicola, M. salarius and M. iranensis, within the genus Marinobacter. Average nucleotide identity and digital DNA-DNA hybridization values between strain TBZ242T and the type strains of the related species of Marinobacter were ≤85.0 and 28.6 %, respectively, confirming that strain TBZ242T represents a distinct species. The major cellular fatty acids of strain TBZ242T were C16 : 0 and C16 : 1 ω7c/C16 : 1 ω6c and the quinone was ubiquinone Q-9. The genomic DNA G+C content of strain TBZ242T is 57.2 mol%. Based on phenotypic, chemotaxonomic and genomic data, strain TBZ242T represents a novel species within the genus Marinobacter, for which the name Marinobacter azerbaijanicus sp. nov. is proposed. The type strain is TBZ242T (= CECT 30649T = IBRC-M 11466T). Genomic fragment recruitment analysis showed that this species prefers aquatic saline environments with intermediate salinities, being detected on metagenomic databases of Lake Meyghan (Iran) with 5 and 18 % salinity, respectively.

Proposed minimal standards for description of new taxa of the class Halobacteria.

Halophilic archaea of the class Halobacteria are the most salt-requiring prokaryotes within the domain Archaea. In 1997, minimal standards for the description of new taxa in the order Halobacteriales were proposed. From then on, the taxonomy of the class Halobacteria provides an excellent example of how changing concepts on prokaryote taxonomy and the development of new methods were implemented. The last decades have witnessed a rapid expansion of the number of described taxa within the class Halobacteria coinciding with the era of genome sequencing development. The current members of the International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Halobacteria propose these revisions to the recommended minimal standards and encourage the use of advanced technologies in the taxonomic description of members of the Halobacteria. Most previously required and some recommended minimal standards for the description of new taxa in the class Halobacteria were retained in the present revision, but changes have been proposed in line with the new methodologies. In addition to the 16S rRNA gene, the rpoB' gene is an important molecular marker for the identification of members of the Halobacteria. Phylogenomic analysis based on concatenated conserved, single-copy marker genes is required to infer the taxonomic status of new taxa. The overall genome relatedness indexes have proven to be determinative in the classification of the taxa within the class Halobacteria. Average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values should be calculated for rigorous comparison among close relatives.

Marinobacter iranensis sp. nov., a slightly halophilic bacterium from a hypersaline lake.

A novel halophilic bacterium, strain 71-iT, was isolated from Inche-Broun hypersaline lake in Golestan province, in the north of Iran. It was a Gram-stain-negative, non-endospore forming, rod-shaped bacterium. It grew at 4-40 °C (optimum 30 °C), pH 6.0-11.0 (optimum pH 7.5) and with 0.5-15 % (w/v) NaCl [optimum 3 % (w/v) NaCl]. The results of phylogenetic analyses based on the 16S rRNA gene sequence comparison indicated its affiliation to the genus Marinobacter and the low percentage of identity with the most closely related species (97.5 %), indicated its placement as a novel species within this genus. Digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) analyses of this strain against closely related species confirmed its condition of novel taxon. On the other hand, the percentage of the average amino acid identity (AAI) affiliated strain 71-iT within the genus Marinobacter. The DNA G+C content of this isolate was 57.7 mol%. The major fatty acids were C16 : 0 and C16 : 1ω7c and/or C16 : 1 ω6c. Ubiquinone-9 was the major isoprenoid quinone and diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE) were the main polar lipids of this strain. On the basis of the phylogenomic and phenotypic (including chemotaxonomic) features, we propose strain 71-iT (= IBRC M 11023T = CECT 30160T = LMG 29252T) as the type strain of a novel species within the genus Marinobacter, with the name Marinobacter iranensis sp. nov. Genomic detections of this strain in various metagenomic databases indicate that it is a relatively abundant species in environments with low salinities (approximately 5 % salinity), but not in hypersaline habitats with high salt concentrations.

Characterization of green synthesized selenium nanoparticles (SeNPs) in two different indigenous halophilic bacteria.

BACKGROUND: In the biological method, using nonpathogenic and extremophile bacteria systems are not only safe and highly efficient but also a trump card for synthesizing nanoparticles. Halomonas elongata QW6 IBRC-M 10,214 (He10214) and Salinicoccus iranensis IBRC-M 10,198 (Si10198), indigenous halophilic bacteria, can be used for synthesizing selenium nanoparticles (SeNPs). METHODS: SeNP biosynthesis was optimized in two halophilic bacteria and characterized by UV-Vis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), zeta potential, and energy dispersive X-ray (EDX). RESULTS: Optimized conditions for synthesizing SeNPs was at 300 °C at 150 rpm for 72 h and 6 mM or 8 mM concentration of Na2SeO3. UV-Vis indicated a sharp absorption peak at 294 nm. Spherical-shaped nanoparticles by a diameter of 30-100 nm were observed in FESEM and TEM microscopy images. The produced SeNPs were identified by a peak in FTIR spectra. In XRD analysis, the highest peak diffraction had a relationship with SeNPs. The zeta potential analysis showed SeNP production, and elemental selenium was confirmed by EDX. CONCLUSIONS: Halophilic bacteria, owing to easy manipulation to create optimization conditions and high resistance, could serve as appropriate organisms for the bioproduction of nanoparticles. The biological method, due to effectiveness, flexibility, biocompatibility, and low cost, could be used for the synthesis of reproducible and stable nanoparticles.

A phenol amine molecule from Salinivenus iranica acts as the inhibitor of cancer stem cells in breast cancer cell lines.

In recent years, the anticancer properties of metabolites from halophilic microorganisms have received a lot of attention. Twenty-nine halophilic bacterial strains were selected from a culture collection to test the effects of their supernatant metabolites on stem cell-like properties of six human cancer cell lines. Human fibroblasts were used as normal control. Sphere and colony formation assay were done to assess the stem cell-like properties. invasion and migration assay, and tumor development in mice model were done to assess the anti-tumorigenesis effect in vitro and in vivo. The metabolites from Salinivenus iranica demonstrated the most potent cytotoxic effect on breast cancer cell lines (IC50 = 100 µg/mL) among all strains, with no effect on normal cells. In MDA-MB-231 cells, the supernatant metabolites enhanced both early and late apoptosis (approximately 9.5% and 48.8%, respectively) and decreased the sphere and colony formation ability of breast cancer cells. Furthermore, after intratumor injection of metabolites, tumors developed in the mice models reduced dramatically, associated with increased pro-apoptotic caspase-3 expression. The purified cytotoxic molecule, a phenol amine with a molecular weight of 1961.73 Dalton (IC50 = 1 µg/mL), downregulated pluripotency gene SRY-Box Transcription Factor 2 (SOX-2) expression in breast cancer cells which is associated with resistance to conventional anticancer treatment. In conclusion, we suggested that the phenol amine molecule from Salinivenus iranica could be a potential anti-breast cancer component.

Selenite bioreduction by a consortium of halophilic/halotolerant bacteria and/or yeasts in saline media.

Selenium oxyanions are released into environments by natural and anthropogenic activities and are present in agricultural and glass manufacturing wastewater in several locations worldwide. Excessive amounts of this metalloid have adverse effects on the health of living organisms. Halophilic and halotolerant microorganisms were selected for selenium oxyanions remediation due to presence of significant amount of salt in selenium-containing wastewater. Effects of aeration, carbon sources, competitive electron acceptors, and reductase inhibitors were investigated on SeO32- bio-removal. Additionally, NO3--containing wastewater were exploited to investigate SeO32- remediation in synthetic agricultural effluents. The results showed that the SeO32- removal extent is maximum in aerobic conditions with succinate as a carbon source. SO42- and PO43- do not significantly interfere with SeO32- reduction, while WO42- and TeO32- decrease the SeO32- removal percentage (up to 35 and 37%, respectively). Furthermore, NO3- had an adverse effect on SeO32- biotransformation by our consortia. All consortia reduced SeO32- in synthetic agricultural wastewaters with a 45-53% removal within 120 h. This study suggests that consortia of halophilic/halotolerant bacteria and yeasts could be applied to treat SeO32--contaminated drainage water. In addition, sulphates, and phosphates do not interfere with selenite bioreduction by these consortia, which makes them suitable candidates for the bioremediation of selenium-containing wastewater.

Genome-resolved analyses of oligotrophic groundwater microbial communities along phenol pollution in a continuous-flow biodegradation model system.

Groundwater pollution is one of the major environmental concerns. The entrance of pollutants into the oligotrophic groundwater ecosystems alters native microbial community structure and metabolism. This study investigated the application of innovative Small Bioreactor Chambers and CaO2 nanoparticles for phenol removal within continuous-flow sand-packed columns for 6 months. Scanning electron microscopy and confocal laser scanning microscopy analysis were conducted to indicate the impact of attached biofilm on sand surfaces in bioremediation columns. Then, the influence of each method on the microbial biodiversity of the column's groundwater was investigated by next-generation sequencing of the 16S rRNA gene. The results indicated that the simultaneous application of biostimulation and bioaugmentation completely eliminated phenol during the first 42 days. However, 80.2% of phenol remained in the natural bioremediation column at the end of the experiment. Microbial diversity was decreased by CaO2 injection while order-level groups known for phenol degradation such as Rhodobacterales and Xanthomonadales dominated in biostimulation columns. Genome-resolved comparative analyses of oligotrophic groundwater prokaryotic communities revealed that Burkholderiales, Micrococcales, and Cytophagales were the dominant members of the pristine groundwater. Six-month exposure of groundwater to phenol shifted the microbial population towards increasing the heterotrophic members of Desulfobacterales, Pseudomonadales, and Xanthomonadales with the degradation potential of phenol and other hydrocarbons.

Use of Microbial Consortia in Bioremediation of Metalloid Polluted Environments.

Metalloids are released into the environment due to the erosion of the rocks or anthropogenic activities, causing problems for human health in different world regions. Meanwhile, microorganisms with different mechanisms to tolerate and detoxify metalloid contaminants have an essential role in reducing risks. In this review, we first define metalloids and bioremediation methods and examine the ecology and biodiversity of microorganisms in areas contaminated with these metalloids. Then we studied the genes and proteins involved in the tolerance, transport, uptake, and reduction of these metalloids. Most of these studies focused on a single metalloid and co-contamination of multiple pollutants were poorly discussed in the literature. Furthermore, microbial communication within consortia was rarely explored. Finally, we summarized the microbial relationships between microorganisms in consortia and biofilms to remove one or more contaminants. Therefore, this review article contains valuable information about microbial consortia and their mechanisms in the bioremediation of metalloids.

Toxic heavy metal/oxyanion tolerance in haloarchaea from some saline and hypersaline ecosystems.

Toxic heavy metal/oxyanion contamination has increased severely through the last decades. In this study, 169 native haloarchaeal strains were isolated from different saline and hypersaline econiches of Iran. After providing pure culture and performing morphological, physiological, and biochemical tests, haloarchaea resistance toward arsenate, selenite, chromate, cadmium, zinc, lead, copper, and mercury were surveyed using an agar dilution method. On the basis of minimum inhibitory concentrations (MICs), the least toxicities were found with selenite and arsenate, while the haloarchaeal strains revealed the highest sensitivity for mercury. On the other hand, the majority of haloarchaeal strains exhibited similar responses to chromate and zinc, whereas the resistance level of the isolates to lead, cadmium, and copper was very heterogeneous. 16 S ribosomal RNA (rRNA) gene sequence analysis revealed that most haloarchaeal strains belong to the Halorubrum and Natrinema genera. The obtained results from this study showed that among the identified isolates, Halococcus morrhuae strain 498 had an exceptional resistance toward selenite and cadmium (64 and 16 mM, respectively). Also, Halovarius luteus strain DA5 exhibited a remarkable tolerance against copper (32 mM). Moreover, strain Salt5, identified as Haloarcula sp., was the only strain that could tolerate all eight tested heavy metals/oxyanions and had a significant tolerance of mercury (1.5 mM).

Carotenoid pigment of Halophilic archaeon Haloarcula sp. A15 induces apoptosis of breast cancer cells.

The halophilic microorganisms living in extreme environments contain high concentrations of carotenoids with notable medical abilities. The purpose of this study was to evaluate the anticancer effect of carotenoids extracted from native Iranian halophilic microorganisms with the ability to inhibit breast cancer cell line. To begin the study, 40 halophilic strains were cultured, and 8 strains capable of producing pigmented colonies were chosen from those cultured strains. In the next step, from among 8 strains using MTT assay, 1 capable of reducing cell viability of the breast cancer MCF-7 cell line was chosen as a selective strain. The principal carotenoid was characterized using UV-visible, FT-IR spectroscopic, and LC-MASS analyses. Using real time PCR technique, the expression of genes specific for apoptosis, in the presence or absence of carotenoid, was examined. Among all strains, carotenoid extracted from strain A15 had the most potent cytotoxic effect on breast cancer cell line (IC50 = 0.0645 mg/mL). 16S rRNA gene analysis showed that strain A15 had similarity with Haloarcula hispanica for about 99.5%. According to the analysis results, it could be estimated that the principal carotenoid extracted form Haloarcula sp. A15 was similar to bacterioruberin. Both early and late apoptosis were increased significantly about 10% and 39%, respectively, due to upregulation of CASP3, CASP8, BAX genes expression in MCF-7 cell line. In contrast, the expression of genes MKI67, SOX2 were significantly downregulated in treated MCF-7 cell line. The results of this study showed that Halophilic archaeon strain could be a good candidate for the production of high added-value bacterioruberin due to its possible anticancer properties.

Hypersaline Lake Urmia: a potential hotspot for microbial genomic variation.

Lake Urmia located in Iran is a hypersaline environment with a salinity of about 27% (w/v). Metagenomic analyses of water samples collected from six locations in the lake exhibited a microbial community dominated by representatives of the family Haloferacaceae (69.8%), mainly those affiliated to only two genera, Haloquadratum (59.3%) and Halonotius (9.1%). Similar to other hypersaline lakes, the bacterial community was dominated by Salinibacter ruber (23.3%). Genomic variation analysis by inspecting single nucleotide variations (SNVs) and insertions/deletions (INDELs) exhibited a high level of SNVs and insertions, most likely through transformation for abundant taxa in the Lake Urmia community. We suggest that the extreme conditions of Lake Urmia and specifically its high ionic concentrations could potentially increase the SNVs and insertions, which can consequently hamper the assembly and genome reconstruction from metagenomic reads of Lake Urmia.

Carotenoids as potential inhibitors of TNFα in COVID-19 treatment.

Tumor necrosis factor-alpha (TNF-α) is a multifunctional pro-inflammatory cytokine, responsible for autoimmune and inflammatory disorders. In COVID-19 patients, increased TNF-α concentration may provoke inflammatory cascade and induce the initiation of cytokine storm that may result in fatal pneumonia and acute respiratory distress syndrome (ADRS). Hence, TNFα is assumed to be a promising drug target against cytokine storm in COVID-19 patients. In the present study, we focused on finding novel small molecules that can directly block TNF-α-hTNFR1 (human TNF receptor 1) interaction. In this regards, TNF-α-inhibiting capacity of natural carotenoids was investigated in terms of blocking TNF-α-hTNFR1 interaction in COVID-19 patients with the help of a combination of in silico approaches, based on virtual screening, molecular docking, and molecular dynamics (MD) simulation. A total of 125 carotenoids were selected out of 1204 natural molecules, based on their pharmacokinetics properties and they all met Lipinski's rule of five. Among them, Sorgomol, Strigol and Orobanchol had the most favorable ΔG with the best ADME (absorption, distribution, metabolism, excretion) properties, and were selected for MD simulation studies, which explored the complex stability and the impact of ligands on protein conformation. Our results showed that Sorgomol formed the most hydrogen bonds, resulting in the highest binding energy with lowest RMSD and RMSF, which made it the most appropriate candidate as TNF-α inhibitor. In conclusion, the present study could serve to expand possibilities to develop new therapeutic small molecules against TNF-α.

Genome-resolved analyses show an extensive diversification in key aerobic hydrocarbon-degrading enzymes across bacteria and archaea.

BACKGROUND: Hydrocarbons (HCs) are organic compounds composed solely of carbon and hydrogen that are mainly accumulated in oil reservoirs. As the introduction of all classes of hydrocarbons including crude oil and oil products into the environment has increased significantly, oil pollution has become a global ecological problem. However, our perception of pathways for biotic degradation of major HCs and key enzymes in these bioconversion processes has mainly been based on cultured microbes and is biased by uneven taxonomic representation. Here we used Annotree to provide a gene-centric view of the aerobic degradation ability of aliphatic and aromatic HCs in 23,446 genomes from 123 bacterial and 14 archaeal phyla.  RESULTS: Apart from the widespread genetic potential for HC degradation in Proteobacteria, Actinobacteriota, Bacteroidota, and Firmicutes, genomes from an additional 18 bacterial and 3 archaeal phyla also hosted key HC degrading enzymes. Among these, such degradation potential has not been previously reported for representatives in the phyla UBA8248, Tectomicrobia, SAR324, and Eremiobacterota. Genomes containing whole pathways for complete degradation of HCs were only detected in Proteobacteria and Actinobacteriota. Except for several members of Crenarchaeota, Halobacterota, and Nanoarchaeota that have tmoA, ladA, and alkB/M key genes, respectively, representatives of archaeal genomes made a small contribution to HC degradation. None of the screened archaeal genomes coded for complete HC degradation pathways studied here; however, they contribute significantly to peripheral routes of HC degradation with bacteria. CONCLUSION: Phylogeny reconstruction showed that the reservoir of key aerobic hydrocarbon-degrading enzymes in Bacteria and Archaea undergoes extensive diversification via gene duplication and horizontal gene transfer. This diversification could potentially enable microbes to rapidly adapt to novel and manufactured HCs that reach the environment.

Induction of the antioxidant defense system using long-chain carotenoids extracted from extreme halophilic archaeon, Halovenus aranensis / Inducción del sistema de defensa antioxidante utilizando carotenoides de cadena larga extraídos de arqueas halofílicas extremas, Halovenus aranensis

The field of microbial pigments is an emerging area in natural products science. Carotenoids form a major class of such pigments and are found to be diversely synthesized by microorganisms that reside in hypersaline ecosystems to provide resistance against oxidative stress. Human cells can benefit from compounds such as carotenoids as antioxidant agents through either their capability to quench free radicals or their effect on promoting the antioxidant defense pathway. In this study, the antioxidant effectiveness of carotenoid extract from an extremely halophilic archaeon Halovenus aranensis strain EB27T has been evaluated using different approaches. Finally, the ability of the extracted pigment to induce the antioxidant defense pathway of human primary skin fibroblast cells was studied. Hvn. aranensis carotenoid extract exhibited strong effectiveness such that at 2 µg/ml, the carotenoid extract fully neutralized the oxidative stress of hydrogen peroxide at its EC50 based on MTT assay. Results from real-time PCR of relevant genes, luciferase bioreporter of oxidative stress, and the western blot analysis further confirmed the antioxidant capability of the carotenoids. It was also shown the carotenoid extract had more antioxidant activity compared to β-carotene the same concentration. Results suggest the carotenoid extract from this archaeon to have high potential for clinical and industrial applications.(AU)

Induction of the antioxidant defense system using long-chain carotenoids extracted from extreme halophilic archaeon, Halovenus aranensis.

The field of microbial pigments is an emerging area in natural products science. Carotenoids form a major class of such pigments and are found to be diversely synthesized by microorganisms that reside in hypersaline ecosystems to provide resistance against oxidative stress. Human cells can benefit from compounds such as carotenoids as antioxidant agents through either their capability to quench free radicals or their effect on promoting the antioxidant defense pathway. In this study, the antioxidant effectiveness of carotenoid extract from an extremely halophilic archaeon Halovenus aranensis strain EB27T has been evaluated using different approaches. Finally, the ability of the extracted pigment to induce the antioxidant defense pathway of human primary skin fibroblast cells was studied. Hvn. aranensis carotenoid extract exhibited strong effectiveness such that at 2 µg/ml, the carotenoid extract fully neutralized the oxidative stress of hydrogen peroxide at its EC50 based on MTT assay. Results from real-time PCR of relevant genes, luciferase bioreporter of oxidative stress, and the western blot analysis further confirmed the antioxidant capability of the carotenoids. It was also shown the carotenoid extract had more antioxidant activity compared to ß-carotene the same concentration. Results suggest the carotenoid extract from this archaeon to have high potential for clinical and industrial applications.

Halophilic Prokaryotes in Urmia Salt Lake, a Hypersaline Environment in Iran.

In this study, fluorescence in situ hybridization (FISH) and PCR-amplified fragments of the 16SrDNA gene were used to determine prokaryotes diversity in Urmia Salt Lake. Prokaryote cell population in Urmia lake range from 3.1 ± 0.3 × 106, 2 ± 0.2 × 108, 4 ± 0.3 × 108, and 1.8 ± 0.2 × 108 cells ml-1 for water, soil, sediment, and salt samples by DAPI (4́, 6-diamidino-2-phenylindole) direct count, respectively. The proportion of bacteria and archaea in the samples determinable by FISH ranged between 36.1 and 55% and 48.5 and 55.5%, respectively. According to the DGGE method, some bands were selected and separated from the gel, then amplified and sequenced. The results of sequences were related to two phyla Proteobacteria (16.6%) and Bacteroidetes (83.3%), which belonged to four genera Salinibacter, Mangroviflexus, Pseudomonas, and Cesiribacter, and the archaeal sequences were related to Euryarchaeota phyla and three genera Halonotius, Haloquadratum, and Halorubrum. According to our results, it seems that prokaryotic populations in this hypersaline environment are more diverse than expected, and bacteria are so abundant and diverse and form the metabolically active part of the microbial population inhabiting this extreme environment. Molecular dependent and independent approaches revealed a different aspect of this environment microbiota.

Distinct microbial community along the chronic oil pollution continuum of the Persian Gulf converge with oil spill accidents.

The Persian Gulf, hosting ca. 48% of the world's oil reserves, has been chronically exposed to natural oil seepage. Oil spill studies show a shift in microbial community composition in response to oil pollution; however, the influence of chronic oil exposure on the microbial community remains unknown. We performed genome-resolved comparative analyses of the water and sediment samples along Persian Gulf's pollution continuum (Strait of Hormuz, Asalouyeh, and Khark Island). Continuous exposure to trace amounts of pollution primed the intrinsic and rare marine oil-degrading microbes such as Oceanospirillales, Flavobacteriales, Alteromonadales, and Rhodobacterales to bloom in response to oil pollution in Asalouyeh and Khark samples. Comparative analysis of the Persian Gulf samples with 106 oil-polluted marine samples reveals that the hydrocarbon type, exposure time, and sediment depth are the main determinants of microbial response to pollution. High aliphatic content of the pollution enriched for Oceanospirillales, Alteromonadales, and Pseudomonadales whereas, Alteromonadales, Cellvibrionales, Flavobacteriales, and Rhodobacterales dominate polyaromatic polluted samples. In chronic exposure and oil spill events, the community composition converges towards higher dominance of oil-degrading constituents while promoting the division of labor for successful bioremediation.

Halomonas azerbaijanica sp. nov., a halophilic bacterium isolated from Urmia Lake after the 2015 drought.

A novel, slightly halophilic bacterium, designated TBZ202T, was isolated from water of Urmia Lake, in the Azerbaijan region of north-west Iran. The strain was facultatively anaerobic, Gram-stain-negative, rod-shaped and motile. Colonies were creamy, circular, convex and shiny. It grew at NaCl concentrations of 0-12 % (w/v) (optimum 3-5 % w/v), at temperatures of 20-45 °C (optimum 30 °C) and at pH 5.0-10.0 (optimum pH 7.0). Based on the 16S rRNA gene sequence, strain TBZ202T belongs to the genus Halomonas in the Halomonadaceae and the most closely related species are Halomonas gudaonensis CGMCC 1.6133T (98.6 % similarity), Halomonas ventosae Al12T (96.8 %) and Halomonas rambilicola RS-16T (96.6%). The G+C content was 67.9 % and the digital DNA-DNA hybridization and average nucleotide identity values with H. gudaonensis were 35.8 and 83.8 %, respectively, indicating that the isolate differs from all species described. The major fatty acids were C18 : 1 ω7c, C16 : 0 and C16 : 1 ω7c. The only respiratory quinone detected was Q-9 and polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, aminophospholipid and three unknown phospholipids. On the basis of a polyphasic taxonomic analysis, the isolate is considered to represent a novel species of the genus Halomonas, for which the name Halomonas azerbaijanica sp. nov. is proposed. The type strain is TBZ202T (=KCTC 62817T=CECT 9693T).