Hypersaline Habitat Research Articles

Coping with salinity extremes: Gill transcriptome profiling in the black-chinned tilapia (Sarotherodon melanotheron)

Steeper and sometimes extreme salinity gradients increasingly affect aquatic organisms because of climate change. Hypersalinity habitats demand powerful physiological adaptive strategies. Few teleost species have the capacity to spend their whole life cycle in salinities way over seawater levels. Focusing on the multifunctional gill, we unraveled the tilapia S. melanotheron key strategies to cope with different environmental conditions, ranging from freshwater up to hypersaline habitats. De novo transcriptome assembly based on RNAseq allowed for the analysis of 40,967 annotated transcripts among samples collected in three wild populations at 0, 40 and 80 ‰. A trend analysis of the expression patterns revealed responses across the salinity gradient with different gene pathways involved. Genes linked to ion transport, pH regulation and cell surface receptor signaling were mainly upregulated in the high salinity habitat. We identified tight junction proteins that were critical in high salinity habitats and that were different from the well-known tightening junctional proteins identified and expressed in fresh water. Expression profiles also suggest a change in the vascular tone that could be linked to an osmorespiratory compromise not only in fresh water, but also in high salinity environments. A striking downregulation of genes linked to the immune system and to the heat shock response was observed suggesting an energetic trade-off between immunity and acclimation/adaptation in the hypersaline habitat. The high expression of transcripts coding for immune and heat shock response in the freshwater habitat suggests the establishment of powerful mechanisms to protect gills from environmental threats and to maintain protein integrity. Non-directional expression trends were also detected with an upregulation of genes only in the hypersaline habitat (80 ‰) or only in the marine habitat (40 ‰). Unravel physiological strategies in S. melanotheron populations will help to better understand the molecular basis of fish euryhalinity in salinity-contrasted environments.

Enchelyothrix muria n. gen, n. sp., (Ciliophora, Litostomatea, Spathidiida), an extreme halotroph spathidiid from Maharloo Lake, Iran

Although free-living ciliated protists (Ciliophora) commonly inhabit aquatic and terrestrial biotopes of mild to moderate salinity (PSS-practical salinity scale S = 10–150), very few have adapted to life at more extreme salinities (>150 to saturation). Such extreme halophiles or halotrophs are of interest from the standpoints of evolution, cell physiology, ecology, and even astrobiology. In this work, we present the morphology, 18S rRNA gene sequence, and phylogenetic analysis of a novel spathidiid ciliate (Ciliophora, Litosatomatea) that thrives in saturated brines of Maharloo Lake, Iran. Based on its unique combination of morphologic features, its molecular characterization, and its unusual ecology, it is assigned to a newly erected monotypic genus incertae sedis in order Spathidiida. The new species differs from other spathidiids by: a cell with a very short acutely pointed tail, the absence of a circumoral kinety with, instead, inclined, interrupted circumoral kinetofragments at the anterior end of somatic kineties and brush rows abutting the oral bulge, the absence of a contractile vacuole, a heteromorphic dorsal brush comprising five or six rows, and an extreme (at or near saturation) hypersaline habitat. We briefly discuss the persistent uncertainties regarding the phylogenetic relationships within the order Spathidiida.

The impact of chemical pollution on the European eel (Anguilla anguilla) from a Mediterranean hypersaline coastal lagoon

The European eel (Anguilla anguilla) is a critically endangered species. The impact of environmental contamination on this species has been highlighted as contributing to the decline in recruitment. The Mar Menor hypersaline coastal lagoon (SE Spain) is one of the most productive fisheries of European eel in Europe, making it a critical habitat for species conservation. The present study aimed to provide an initial overview of the impact of organic chemical contaminants on the European eel and the potential sublethal effects of chemical pollution on pre-migrating eels in this hypersaline habitat. We investigated muscle bioaccumulation of main persistent and hazardous organic contaminants (including some current-use pesticides) and genotoxicity, neurotoxicity, and xenobiotic detoxification system responses. The findings show that lagoon eels were exposed to high levels of legacy organochlorine contaminants, recently banned pesticides (chlorpyrifos), and some emerging chemicals. Some individuals surpassed the maximum levels of CBs authorized by the European Commission for human consumption. In this species, residuals of chlorpyrifos, pendimethalin, and chlorthal dimethyl have been reported for the first time. This field study provides relevant data to stock management and human health consumption and provides the first biomarker responses in European eel under permanent hypersaline conditions. Furthermore, the high frequency of micronuclei in peripheral erythrocytes of lagoon eels indicates sublethal genotoxic effects on the organism. Overall, the European eels growing and maturing in the Mar Menor lagoon are exposed to toxic and carcinogenic chemicals. The lack of seafood safety regulations for human consumption for some legacy chemicals that were measured in high concentrations in our study requires special action. Further biomonitoring and research are recommended to protect the animal, public, and environmental health.

Macrozoobenthos Structure and Dynamics in a Mediterranean Hypersaline Ecosystem with Implications for Wetland Conservation

Within the framework of hypersaline environments, the Saline di Tarquinia salterns (Latium, Italy) represent an interesting case study from ecological, naturalistic, and conservationist perspectives. We studied macrozoobenthic community zonation related to the main environmental parameters, with particular emphasis on the beetle species Nebrioporus ceresyi (Aubé, 1836), one of the few Dytiscidae among Italian fauna particularly adapted to brackish and hypersaline waters. In this study, we report the structure and seasonal dynamics of the macrozoobenthic community, the spatial and temporal distribution of both larvae and adults of N. ceresyi, and the size–frequency distribution of the larvae. The results add new information on the macrozoobenthic assemblage of the Saline di Tarquinia salterns and the life cycle of this water beetle in the hypersaline habitat. A possible hypothesis about the discontinuous geographical distribution of the species of Dytiscidae investigated is also provided. Finally, N. ceresyi is proposed as an indicator species useful in characterizing the environmental zonation of hypersaline habitats.

Metagenomic Insights into Microbial Community Structure, Function, and Salt Adaptation in Saline Soils of Arid Land, China.

Soil salinization is spread in the dryland of NW China due to the dry or extreme dry climate. Increased salinization damages the health and function of soil systems and influences the microbial community structure and function. Some studies have been conducted to reveal the microbial community structure and isolate the microorganisms of saline soil or salt-lake sediments in this region. However, the functions of microorganisms and their response to salinization, i.e., their adaptation strategy to a wide salinization range in arid environments, are less understood. Here, we applied metagenomics technology to investigate the microbial community structure, function, and their relationship with salinization, and discussed the adaptative strategy of microorganisms to different saline environments. A total of 42 samples were sequenced on the Illumina PE500 platform. The archaea and bacteria constituted the dominant kingdoms; Actinobacteria, Proteobacteria, Bacteroidetes, and Firmicutes were the dominant bacterial phyla; and Euryarchaeota were the dominant archaeal phylum. The microbial communities showed significant structure divergence according to the salt concentration (saline (mean EC 22 mS/cm) and hypersaline (mean EC 70 mS/cm)), wherein the communities were dominated by bacteria in saline soils and archaea in hypersaline soils. Most of the dominant bacterial representation decreased with salinity, while the archaea increased with salinity. KEGG functional annotation showed that at level 2, the cell motility, environmental adaptation, signal transduction, signaling molecules and interaction, glycan biosynthesis and metabolism, and metabolism of other amino acids were reduced from saline to hypersaline, whereas the metabolism of cofactors and vitamins, folding sorting and degradation, replication and repair, transcription and translation, amino acid biosynthesis, glycolysis/gluconeogenesis, and carbon fixation increased with salinity. The increased salt content decreased the carbohydrate activities of microorganisms. The osmolyte regulation substance synthesis and absorption-related genes were more abundant in saline soils than in hypersaline soils, whereas the Na+/H+ antiporter genes (mnhB-E) and H+/Na+-transporting ATPase genes (atpA-F, I, K) were significantly higher in hypersaline soils. This indicated that in saline soils, microorganisms primarily synthesize and/or uptake compatible solutes to cope with osmotic stress, whereas in the hypersaline habitat, the high-salt-in strategy was predicated to be adopted by the halophilic/extremely halophilic microorganisms, coupled with a high abundance of replication and repair, cofactors and vitamin metabolism, nucleotide metabolism, and carbon fixation to provide energy and ensure cell regeneration. In conclusion, increases in salinity influence the microbial communities' structure and function, as well as the adaptation of microorganisms.

Oligotrophy vs. copiotrophy in an alkaline and saline habitat of Lonar Lake.

We reported our comparative observations on oligotrophs vs. copiotrophs from a hyper-alkaline and hypersaline habitat, Lonar Lake, situated in the Buldhana district of Maharashtra, India. Cell numbers of oligotrophic and copiotrophic microbes from the sediment were enumerated by the three-tube most probable number (MPN) method using an array of nutrient-rich and oligotrophic (≈10–20 mg carbon L−1) media offering simulated natural conditions of pH and salinity. A total of 50 strains from 15 different genera and 30 different species were isolated from the highest positive dilutions of MPN to identify the taxa of oligotrophs and copiotrophic microorganisms dominating in Lonar Lake. We did not get any true oligotrophs due to their adaptation to higher carbon levels during the isolation procedure. On the contrary, several true copiotrophs, which could not adapt and survive on a low-carbon medium, were isolated. It is also observed that changes in medium composition and nutrient level altered the selection of organisms from the same sample. Our data indicate that copiotrophic microorganisms dominate the eutrophic Lonar Lake, which is also supported by the past metagenomics studies from the same site. We also reported that quick depletion of carbon from oligotrophic medium worked as a limiting factor, inducing cell death after 2–3 generations and preventing the development of visible colonies on plates and sufficient optical density in liquid medium. Therefore, a long-term supply of low levels of carbon, followed by isolation on enriched media, can serve as a good strategy in isolation of novel taxa of microorganism, with industrial or environmental importance.

Salt- and pH-Dependent Thermal Stability of Photocomplexes from Extremophilic Bacteriochlorophyll b-Containing Halorhodospira Species.

Halorhodospira (Hlr.) species are the most halophilic and alkaliphilic of all purple bacteria. Hlr. halochloris exhibits the lowest LH1 Qy transition energy among phototrophic organisms and is the only known triply extremophilic anoxygenic phototroph, displaying a thermophilic, halophilic, and alkaliphilic phenotype. Recently, we reported that electrostatic charges are responsible for the unusual spectroscopic properties of the Hlr. halochloris LH1 complex. In the present work, we examined the effects of salt and pH on the spectroscopic properties and thermal stability of LH1-RCs from Hlr. halochloris compared with its mesophilic counterpart, Hlr. abdelmalekii. Experiments in which the photocomplexes were subjected to different levels of salt or variable pH revealed that the thermal stability of LH1-RCs from both species was largely retained in the presence of high salt concentrations and/or at alkaline pH but was markedly reduced by lowering the salt concentration and/or pH. Based on the amino acid sequences of LH1 polypeptides and their composition of acidic/basic residues and the Hofmeister series for cation/anion species, we discuss the importance of electrostatic charge in stabilizing the Hlr. halochloris LH1-RC complex to allow it to perform photosynthesis in its warm, hypersaline, and alkaline habitat.

Electrostatic charge controls the lowest LH1 Qy transition energy in the triply extremophilic purple phototrophic bacterium, Halorhodospira halochloris

Halorhodospira (Hlr.) halochloris is a unique phototrophic purple bacterium because it is a triple extremophile—the organism is thermophilic, alkalophilic, and halophilic. The most striking photosynthetic feature of Hlr. halochloris is that the bacteriochlorophyll (BChl) b-containing core light-harvesting (LH1) complex surrounding its reaction center (RC) exhibits its LH1 Qy absorption maximum at 1016 nm, which is the lowest transition energy among phototrophic organisms. Here we report that this extraordinarily red-shifted LH1 Qy band of Hlr. halochloris exhibits interconvertible spectral shifts depending on the electrostatic charge distribution around the BChl b molecules. The 1016 nm band of the Hlr. halochloris LH1-RC complex was blue-shifted to 958 nm upon desalting or pH decrease but returned to its original position when supplemented with salts or pH increase. Resonance Raman analysis demonstrated that these interconvertible spectral shifts are not associated with the strength of hydrogen-bonding interactions between BChl b and LH1 polypeptides. Furthermore, circular dichroism signals for the LH1 Qy transition of Hlr. halochloris appeared with a positive sign (as in BChl b-containing Blastochloris species) and opposite those of BChl a-containing purple bacteria, possibly due to a combined effect of slight differences in the transition dipole moments between BChl a and BChl b and in the interactions between adjacent BChls in their assembled state. Based on these findings and LH1 amino acid sequences, it is proposed that Hlr. halochloris evolved its unique and tunable light-harvesting system with electrostatic charges in order to carry out photosynthesis and thrive in its punishing hypersaline and alkaline habitat.

Irreversible habitat specialization does not constrain diversification in hypersaline water beetles.

Specialization to extreme environments is often considered an evolutionary dead-end, leading to irreversible adaptations and reduced evolvability. There is, however, mixed evidence for this macroevolutionary pattern, and limited data from speciose lineages. Here, we tested the effect of habitat specialization to hypersaline waters in the diversification rates of aquatic beetles of the genus Ochthebius (Coleoptera, Hydraenidae), using a molecular phylogeny with more than 50% of the 546 recognized species, including representatives of all but one of the nine recognized subgenera and 17 species groups. Phylogenies were built combining mitochondrial and nuclear genes, with the addition of 42 mitochondrial genomes. Using Bayesian methods of character reconstruction, we show that hypersaline tolerance is an irreversible ecological specialization that arose multiple times. Two lineages of Ochthebius experienced a significant increase in diversification rates, one of them inhabiting hypersaline waters, but there was no overall correlation with habitat or any significant decrease in diversification rates despite the irreversibility of hypersaline tolerance. Our study tested for the first time the impact of hypersaline habitat specialization on diversification rates, finding no support for it to be an evolutionary dead-end. On the contrary, multiple and ancient lineages fully adapted to these extreme osmotic conditions have persisted and diversified over a long evolutionary timescale.

Morphological, molecular characterization and biofilm inhibition effect of endophytic Frankia sp. from root nodules of Actinorhizal plant Casuarina sp.

Frankia is a mycelium-forming actinobacterial genus that is found in actinorhizal plants as a nitrogen-fixing facultative endo-symbiont. Frankia has been a commonly uncultured endophytic actinobacteria with very slow growth germination. In the present study, the root nodules from Casuarina spp. were collected at hyper-saline and terrestrial habitats in Tamil Nadu, South India. The root nodules were surface-sterilized, dried, homogenized, and inoculated on the DPM medium with sodium propionate as a carbon source and biotin as a vitamin source. A total of 11 Frankia isolates were obtained from the specified habitats in a solid and liquid medium. The larger number of isolates was recorded in the hyper-saline habitats compared to terrestrial habitats. Finally, 2 predominant growth occurrences of isolates were selected; from each habitat, unique isolates were molecularly characterized and identified as Frankia sp. DDNSF-01 and Frankia casuarinae DDNSF-02. The physico-chemical property analysis of Casuarina rhizosphere soil of hyper-saline habitat showed higher pH, salinity and micro-nutrients like Fe−, Mn−, Cu−, and Zn− than terrestrial habitats, which could be the major factors responsible for the distribution dynamics of Frankia in hyper-saline habitats. Similarly, the biologically active metabolites of Frankia spp. were extracted by the ethyl acetate extraction method and tested by MIC assay, which was performed against emerging multi-host pathogens like Pseudomonas sp. and Candida sp. Likewise, the antibiofilm activity assay was done against the above pathogens. The biofilm inhibition of live/dead cells was confirmed by CLSM microscopic analysis. The F. casuarinae was inhibited the high level of biofilm formation of both pathogens when compared with Frankia sp. The present findings conclude the F. casuarinae is efficient in the control of emerging multi-host pathogens in actinorhizal plants.

Effects of light, temperature, salinity, and maternal habitat on seed germination of Aeluropus lagopoides (Poaceae): an economically important halophyte of arid Arabian deserts

In this study, salt tolerance during germination of Aeluropus lagopoides (L.) Trin. was tested using fresh seeds collected from three different maternal habitats under three thermoperiods and two light regimes. Additionally, we tested the ability of non-germinated seeds that had been exposed to different concentrations of NaCl to recover their germination in distilled water. The results showed a significant effect of seed source, temperature, and salinity, and some of their two- and three-way interactions on final germination and recovery percentage. The seeds from non-saline provenances had the highest percentages for germination (ca. 79%) under the 35/25 °C temperature regime, whereas the lowest percentages for germination (ca. 21%) was recorded for seeds from saline conditions under the 25/15 °C treatment. Additionally, percent germination was significantly lower for the seeds incubated in the saline solutions (100, 200, 400, and 600 mmol/L NaCl) and germinated under colder conditions (15/25 °C), compared with the seeds incubated in non-saline solutions (control group, 0 mmol/L NaCl) and germinated under warmer conditions (35/25 °C). The highest recovery percentage was recorded for seeds of the hyper-saline habitat incubated at 35/25 °C. Thus, seeds maintained their viability despite experiencing a range of saline conditions and were able to germinate upon the arrival of suitable conditions, which can be an adaptation to its saline arid desert habitat.

Glenathe salina (Diptera: Ephydridae): New Freshwater, Saline Habitat and County Records in Ohio

The collection of Glenanthe salina Mathis in a freshwater restored wetland in Hamilton County, Ohio is a new county record and represents a significant range extension within the state. For the first time, G. salina was collected from an Ohio saline habitat (Wayne County) and is a new county and an eastern North American inland salt habitat record. Glenanthe salina records from freshwater, saline, and alkaline habitats suggest broad osmoregulation capacity. Collection records suggest that G. salina and Psilopa girschneri colonized saline habitats at Rittman, Ohio during 1996 and 1976, respectively. During the early half of the twentieth century, hyper saline habitat at Rittman, Ohio was colonized by Ephydra gracilis Packard, and E. niveiceps Cresson, which have been commonly reported from saline habitats in western North America.

Glycomyces xinjiangensis sp. nov., a novel actinomycete isolated from a hypersaline habitat.

A novel actinomycete strain, designated XHU 5301T, was isolated from a hypersaline habitat, China. The strain was aerobic, Gram-stain positive and the optimum NaCl concentration for growth was 7-9% (w/v). Phylogenetic analysis based on an almost-complete 16S rRNA gene sequence of strain XHU 5301T showed that the organism was most closely related to Glycomyces halotolerans TRM 40137T (96.0%). The whole-cell sugar pattern consisted of glucose and galactose. The predominant menaquinone was MK-10(H4), MK-10(H2), and MK-9(H4). The major fatty acids were anteiso-C15: 0, iso-C15: 0, iso-C16: 0, and methyl-C19: 0. The polar lipids consist of diphosphatidylglycerol, phosphatidylglycerol, and one unknown phospholipid. The G+C content of the genomic DNA was 72.5mol%. The novel species Glycomyces xinjiangensis sp. nov. was proposed, with strain XHU 5301T (=CCTCC AA 2016043T=KCTC 39689T) as the type strain of Glycomyces xinjiangensis.

Characterization of basidiomycetous yeasts in hypersaline soils of the Urmia Lake National Park, Iran.

Urmia Lake, located in northwest Iran, is an oligotrophic and extremely hypersaline habitat that supports diverse forms of life. Owing to its unique biodiversity and special environmental conditions, Urmia Lake National Park has been designated as one of the biosphere reserves by UNESCO. This study was aimed to characterize basidiomycetous yeasts in hypersaline soils surrounding the Urmia Lake National Park using a polyphasic combination of molecular and physiological data. Soil samples were collected from eight sites in Lake Basin and six islands insides the lake. Yeast strains were identified by sequencing the D1/D2 domains of the 26S rRNA gene. When D1/D2 domain sequencing did not resolve the identity of the species, strain identification was obtained by ITS 1 & 2 sequencing. Twenty-one species belonging to the genera Cystobasidium, Holtermanniella, Naganishia, Rhodotorula, Saitozyma, Solicoccozyma, Tausonia, Vanrija, and Vishniacozyma were identified. Solicoccozyma aeria represented the dominant species. The ability of isolates to grow at 10 and 15% of NaCl was checked; about two-thirds of the strains grew at 10%, while about 13% of the isolates grew in medium with 15% NaCl. this study is the first study on the culturable yeast diversity in hypersaline soils surrounding an Asian lake.

Glycomyces lacisalsi sp. nov., an actinomycete isolated from a hypersaline habitat.

A novel actinomycete strain, designated XHU 5089T, was isolated from a hypersaline habitat in China. The strain was aerobic, Gram-stain-positive and the optimum NaCl concentration for growth was 1-3 % (w/v). Phylogenetic analysis based on the almost-complete 16S rRNA gene sequence of strain XHU 5089T showed that the organism was related most closely to Glycomyces albusTRM 49136T (97.7 % similarity). However, it had a relatively low mean DNA-DNA relatedness value with G. albusTRM 49136T (18.9±5.8 %). The whole-cell sugar pattern consisted of glucose and galactose. The predominant menaquinones were MK-10(H4) and MK-9(H4). The major fatty acids were anteiso-C15 : 0, iso-C16 : 0, iso-C16 : 1 and anteiso-C17 : 0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unidentified glycolipids and two unknown phospholipids. The G+C content of the genomic DNA was 68.6 mol%. A novel species, Glycomyces lacisalsi sp. nov., is proposed, with XHU 5089T (=CCTCC AA 2015034T=KCTC 39688T) as the type strain.

Drought conditions and recovery in the Coorong wetland, south Australia in 1997–2013

Between 2004 and 2009, South Australia suffered its longest period of below average annual rainfall. This impacted riverine ecosystems and particularly the Murray-Darling Basin (MDB), the largest river system in Australia. The MDB combines 30,000 wetlands of which the Coorong wetland is of significant importance for the reproduction of bird and fish species, and is listed under the Ramsar Convention. We sampled water in the Coorong wetland between 2011 and 2013 and compiled additional data from 1997 to 2013 to assess the impact of the drought and subsequent recovery of the environment. The salinity levels of the Coorong wetland increased dramatically during the drought because of the lack of freshwater inflow from the Murray River. The changes in water flow observed from 2002 to 2009 had an impact on the number of habitats present along the Coorong wetland. In addition, a shift in community composition was observed between the freshwater habitat (<5) dominated by chlorophytes to the hypersaline habitat (>85) dominated by diatoms. It is evident that during the drought, the Coorong wetland was dominated by diatoms and dinoflagellates. After the drought, the North Lagoon was dominated by chlorophytes up to a salinity level of 20. However, over 20 and in the South Lagoon, diatoms dominated the community. This study highlights how salinity levels drive the phytoplankton community. Based on the complementary data obtained for salinity between 1997 and 2010, there is a significant difference between the salinity levels observed during the drought and those observed before and after the drought. It appears that salinity levels are now recovered to what they were in the late 1990s.

Erratum to: Phialosimplex salinarum, a new species of Eurotiomycetes from a hypersaline habitat

On p. 170 in this paper, published online on 9 October 2014, the spelling adopted for the name of the new combination “Phialosimplex halophila” should be corrected to “Phialosimplex halophilus”. This is an orthographic error which is correctable under the Code (Art. 60. 12) and so does not necessitate a new MycoBank number.

Saccharopolyspora halotolerans sp. nov., a halophilic actinomycete isolated from a hypersaline lake.

A novel actinomycete strain, designated TRM 45123(T), was isolated from a hypersaline habitat in Xinjiang Province (40° 20' N 90° 49' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45123(T) belonged to the genus Saccharopolyspora and was closely related to Saccharopolyspora gloriosae (96.7% similarity). The G+C content of the DNA was 69.07 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C17:0, iso-C15:0 and anteiso-C15:0. On the basis of the evidence from this polyphasic study, a novel species, Saccharopolyspora halotolerans sp. nov., is proposed. The type strain of Saccharopolyspora halotolerans is TRM 45123(T) ( = CCTCC AA 2013006(T) = DSM 45990(T)).

Streptomonospora algeriensis sp. nov., a halophilic actinomycete isolated from soil in Algeria.

A halophilic actinomycete strain, designated H27(T), was isolated from a soil sample collected from a hypersaline habitat in Djelfa Province (North-Central Algeria), and then investigated using a polyphasic taxonomic approach. The strain was observed to produce poor aerial mycelium, which formed short chains of oval to cylindrical-shaped spores at maturity, and non fragmented substrate mycelium. The optimum NaCl concentration for growth was found to be 10-15% (w/v) and the optimum growth temperature and pH were found to be 28-37°C and 6-7, respectively. The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. The predominant menaquinones of strain H27(T) were identified as MK-11 (H4) and MK-10 (H6). The major fatty acids were found to be iso-C16:0, anteiso-C17:0, 10 methyl C17:0 and 10 methyl C16:0. The diagnostic phospholipids detected were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. The chemotaxonomic properties of strain H27(T) are consistent with those shared by members of the genus Streptomonospora. 16S rRNA gene sequence analysis indicated that strain H27(T) is most closely related to Streptomonospora alba DSM 44588(T) (98.8%) and Streptomonospora flavalba DSM 45155(T) (98.7%) whereas the DNA-DNA relatedness values between strain H27(T) and the two type strains were 17.1 and 57.9%, respectively. Based on the combined genotypic and phenotypic evidence, it is proposed that strain H27(T) should be classified as representative of a novel species, for which the name Streptomonospora algeriensis sp. nov. is proposed. The type strain is H27(T) (=DSM 45604(T) =CCUG 63369(T) =MTCC 11563(T)).

Glycomyces fuscus sp. nov. and Glycomyces albus sp. nov., actinomycetes isolated from a hypersaline habitat.

Two actinomycete strains, designated TRM 49117(T) and TRM 49136(T), were isolated from a hypersaline habitat in Xinjiang Province, north-west China and were characterized taxonomically by using a polyphasic study. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain TRM 49117(T) had 93.93% similarity with the type strain Glycomyces halotolerans TRM 40137(T) (GenBank accession no. HQ651156) and TRM 49136(T) had 94.32% similarity with G. halotolerans TRM 40137(T). The 16S rRNA gene sequence similarity between the two new isolates was 93%. The isolates contained meso-diaminopimelic acid as the diagnostic diamino acid and anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 as major cellular fatty acids. The predominant menaquinones of the isolates were MK-9(H4) and MK-9(H6). The whole-cell sugar patterns of these strains contained xylose and ribose, and strain TRM 49136(T) also contained arabinose. The polar lipid pattern of strain TRM 49117(T) comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylcholine, phosphatidylinositol and three additional unknown phospholipids. The polar lipid pattern of strain TRM 49136(T) comprised phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, glycolipids and two phosphoglycolipids of unknown composition. Genotypic and phenotypic data confirmed that strains TRM 49117(T) and TRM 49136(T) represent two novel species, clearly different from related species of the genus Glycomyces, for which the names Glycomyces fuscus sp. nov. (type strain TRM 49117(T) = CCTCC AA 2013003(T) = NRRL B-59998(T) = KACC 17682(T)) and Glycomyces albus sp. nov. (type strain TRM 49136(T) = CCTCC AA 2013004(T) = NRRL B-24927(T) = KACC 17681(T)) are proposed.