Minimal NaCl Concentration Research Articles

Environmentally sound geotechnologies for leaching metals from polymetallic ore processing wastes and wastewater

Global challenges (increased consumption of georesources, climatic changes, limited reserves) increase the relevance of the problems of growing waste accumulation and environmentally-sound modernization of mineral extraction. In this regard, the existing approaches to the design of geotechnologies for metal mining need to be improved based on a concept of so-called circulation waste management and ecologization of technological processes. The paper is devoted to the issue of formation of conceptual bases and directions of ecologization of geotechnologies at leaching metals from polymetallic ore processing wastes and wastewater. The study presents recommendations for improving in-situ leaching of ores in blocks, allowing to determine the optimal conditions for increasing the completeness of subsoil use and reducing environmental damage. It was revealed that at metal extraction with solution circulation through brine chambers the content of Na, Cl, SO4 and Ca ions in dialysate was low, while without circulation through brine, it significantly exceeded corresponding MPCs. This proves the fundamental feasibility of controlling natural leaching processes by enhancing the oxidizing potential of natural solvents through the addition of industrial oxidizing agents. It was found that increasing the duration of agitation leaching (both with and without mechanoactivation) leads to a uniform expansion of the local maximums of Pb yield from the pulp when the minimum NaCl concentration decreases from 11–12 to 7% at H2SO4 concentration of 0.6%. One of key results of the study is justifying the expansion of the use of disintegrators to realize targeted activation of tailings. The practical significance of the obtained results lies in the proved feasibility of optimizing the flow sheet of electrochemical extraction of metals from wastewater on the basis of the obtained regularities of the use of brine circulation through brine chambers. In addition, the totality of the obtained results of using a disintegrator for reextraction of lead from geomaterials will allow developing a methodology for calculating the parameters of mechanoactivation action to increase the degree of metal recovery from the tailings of North Ossetia-Alania’s (Zgidskoe, Sadonskoe, Arkhonskoe deposits) polymetallic ores beneficiation. The most promising way for further research is to substantiate methods of using underground space for complete removal of wastes (wastewater and tailings) after their multistage treatment.

Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., low salt-tolerant haloarchaea isolated from seawater and sediment.

Three novel halophilic archaea were isolated from seawater and sediment near Yeoungheungdo Island, Republic of Korea. The genome size and G + C content of the isolates MBLA0076T, MBLA0077T, and MBLA0078T were 3.56, 3.48, and 3.48Mb and 61.7, 60.8, and 61.1mol%, respectively. The three strains shared 98.5-99.5 % sequence similarity of the 16S rRNA gene, whereas their sequence similarity to the 16S rRNA gene of type strains was below 98.5 %. Phylogenetic analysis based on sequences of the 16S rRNA and RNA polymerase subunit beta genes indicated that the isolates belonged to the genus Haloferax. The orthologous average nucleotide identity, average amino-acid identity, and in silico DNA-DNA hybridization values were below species delineation thresholds. Pan-genomic analysis indicated that the three novel strains and 11 reference strains had 8981 pan-orthologous groups in total. Fourteen Haloferax strains shared 1766 core pan-genome orthologous groups, which were mainly related to amino acid transport and metabolism. Cells of the three isolates were gram-negative, motile, red-pink pigmented, and pleomorphic. The strains grew optimally at 30°C (MBLA0076T) and 40°C (MBLA0077T, MBLA0078T) in the presence of 1.28M (MBLA0077T) and 1.7M (MBLA0076T, MBLA0078T) NaCl and 0.1M (MBLA0077T), 0.2M (MBLA0076T), and 0.3M (MBLA0078T) MgCl2·6H2O at pH 7.0-8.0. Cells of all isolates lysed in distilled water; the minimum NaCl concentration necessary to prevent lysis was 0.43M. The major polar lipids of the three strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and sulphated diglycosyl archaeol-1. Based on their phenotypic and genotypic properties, MBLA0076T, MBLA0077T, and MBLA0078T were described as novel species of Haloferax, for which we propose the names Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., respectively. The respective type strains of these species are MBLA0076T (= KCTC 4288T = JCM 34,169T), MBLA0077T (= KCTC 4289T = JCM 34,170T), and MBLA0078T (= KCTC 4290T = JCM 34,171T).

Halalkalirubrum salinum gen. nov., sp. nov., a halophilic archaeon isolated from a saline lake.

A novel extremely halophilic archaeon, strain N1521T, was isolated from a saline lake in Tibet, China. Cells of the strain were pleomorphic and Gram-stain-negative. It produced red pigments. Growth was observed at 4-42°C (optimum, 37°C), pH 7.0-10.5 (optimum, 8.0-9.5), NaCl 11%-25% (optimum, 15%) and in the presence of 0-0.1M MgCl2 (optimum, 0.05M) in aerobic conditions. The minimum NaCl concentration that prevented cell lysis was 2% (w/v). The major polar lipids of strain N1521T were phosphatidylglycerol sulfate, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol and an unidentified glycolipid. The DNA G + C content was 58.37mol%. According to 16S rRNA gene sequence comparisons, strain N1521T revealed the highest sequence similarity to Haloprofundus halophilus NK23T (91.38%) and Halogranum amylolyticum TNN58T (91.00%), and low sequence similarities (< 91%) with other genera in the order Haloferacales. Phylogenetic analysis based on the 16S rRNA gene and rpoB' gene sequence showed that strain N1521T was distinct from the members of the order Haloferacales. The digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values calculated from whole genome-sequence comparison between strain N1521T and the members of the order Haloferacales were in the ranges of 15.1-18.2%, 68.8-73.0%, and 58.4-63.9%, respectively. Phylogenetic tree reconstructions based on the whole-genome sequences revealed that strain N1521T was closer to the members of the family Halorubraceae. Based on the data obtained, strain N1521T is thus considered to represent a novel species of a new genus within the family Halorubraceae, for which the name Halalkalirubrum salinum gen. nov., sp. nov. is proposed. The type strain is N1521T (= CGMCC 1.16693 = JCM 33785).

Synthesis mechanism of cuprous oxide nanoparticles by atmospheric-pressure plasma electrolysis

The synthesis mechanism of cuprous oxide (Cu2O) nanoparticles by atmospheric-pressure plasma electrolysis was investigated experimentally. In the plasma electrolysis system, a helium plasma in contact with an NaCl electrolyte was used as the cathode, while a copper plate which was partly immersed into the electrolyte was used as the counter electrode. X-ray powder diffraction, field-emission scanning electron microscopy, and transmission electron microscopy were used for characterizing the synthesized products. The results indicate that the Cl− concentration and the pH value of the electrolyte dominate the synthesis of Cu2O nanoparticles. The reaction between CuCl produced via the anodic dissolution of Cu and OH− produced by plasma irradiation is responsible for the formation of Cu2O. The comparison between the plasma and conventional electrolysis has also been carried out, since the anodic dissolution of the Cu plate and the production of OH− are also available in the conventional electrolysis. As a result, we also observed the synthesis of Cu2O nanoparticles by the conventional electrolysis. However, we observed the differences between the plasma and conventional electrolysis in the synthesis rate, the minimum NaCl concentration, and the size and the shape of synthesized nanoparticles.

Natrialba swarupiae sp. nov., a halophilic archaeon isolated from a hypersaline lake in India.

A haloarchaeal strain (ESP3B_9T) was isolated from the salt pan of Sambhar salt lake, Rajasthan, India. Cells were coccoid, non-motile, Gram-stain-negative and formed reddish-pink pigmented colonies. The strain was aerobic, able to grow at 35-55 °C (optimum, 40 °C), in 20-35 % (25 %) NaCl and pH 8-10 (pH 9). Mg2+ not required for growth. The cells were lysed in distilled water and the minimum NaCl concentration that prevented cell lysis was 5 % w/v. The 16S rRNA gene sequence similarities between strain ESP3B_9T and Natrialba hulunbeirensis JCM 10989T and Natrialba magadii ATCC 43099T were 96.53 and 96.25 % respectively. The similarities of the RNA polymerase subunit B gene between strain ESP3B_9T and N. hulunbeirensis JCM 10989T and N. magadii ATCC 43099T were 84.47 and 84.9 % respectively. Genome sequencing revealed a genome size of 4.20 Mbp with DNA G+C content of 62.5 mol%. The major polar lipids were phosphotidylglycerol and phosphatidylglycerol phosphate methyl esters with minor amounts of unidentified lipids. The results of polyphasic analysis determined that strain ESP3B_9T represents a novel species of the genus Natrialba, for which the name Natrialba swarupiae sp. nov. is proposed. The type strain is ESP3B_9T (MCC 3419T=JCM 33002T=KCTC 4279T=CGMCC 1.16737T).

Halostella limicola sp. nov., isolated from saline soil sampled at the Tarim Basin

A halophilic archaeaon, strain LT12T, was isolated from saline soil sampled at the Tarim Basin, PR China. The novel strain stained Gram-negative, cells were rod-shaped, and formed light red-pigmented colonies on agar plate. Strain LT12T grew optimally at 3.1 M NaCl, 0.05 M MgCl2, 37 °C and pH 7.5. The cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 1.4 M. Based on the results of phylogenetic analyses of the 16S rRNA and rpoB' genes, strain LT12T was most closely related to Halostella salina CBA1114T(94.4-95.9 and 93.6 % similarities, respectively). The average nucleotide identity and in silico DNA-DNA hybridization values between strain LT12T and H. salina CBA1114T were 81.0 and 24.3 %, respectively. The major polar lipids of strain LT12T were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and three unidentified glycolipids. The DNA G+C content was 67.2 mol % (genome). Based on the phenotypic, chemotaxonomic and phylogenetic properties, strain LT12T represents a novel species of the genus Halostella for which the name Halostellalimicola sp. nov. is proposed. The type strain is LT12T (=CGMCC 1.14941T=JCM 30667T).

Halorussus litoreus sp. nov., isolated from the salted brown alga Laminaria.

A halophilic archaeal strain, designated HD8-51T, was isolated from the salted brown alga Laminaria. Cells of strain HD8-51T were motile, pleomorphic coccoid or ovoid, and formed red-pigmented colonies on agar plates. Strain HD8-51T grew optimally at 3.1 M NaCl, 0.03 M MgCl2, 30 °C and pH 7.0. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 0.85 M. Based on phylogenetic analyses of the 16S rRNA and rpoB' genes, strain HD8-51T was most closely related to members of the genus Halorussus (92.3-95.6 % and 89.2-91.7% similarities, respectively). The average nucleotide identity values and in silico DNA-DNA hybridization values between strain HD8-51T and Halorussus rarus TBN4T were 81.69 and 24.5 %, respectively. The major polar lipids of strain HD8-51T were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and five glycolipids, sulfated galactosyl mannosyl glucosyl diether (S-TGD-1), galactosyl mannosyl glucosyl diether (TGD-1), sulfated mannosyl glucosyl diether (S-DGD-1), mannosyl glucosyl diether (DGD-1) and diglycosyl diether (DGD-2). The DNA G+C content was 65.9 mol%. Based on phenotypic, chemotaxonomic and phylogenetic properties, strain HD8-51T represents a novel species of the genus Halorussus, for which the name Halorussus litoreus sp. nov. is proposed. The type strain is HD8-51T (=CGMCC 1.15333T=JCM 31109T).

Aggregation-phase diagrams of β2-microglobulin reveal temperature and salt effects on competitive formation of amyloids versus amorphous aggregates

Several serious diseases are associated with crystal-like amyloid fibrils or glass-like amorphous aggregates of denatured proteins. However, protein aggregation involving both types of aggregates has not yet been elucidated in much detail. Using a protein associated with dialysis-related amyloidosis, β2-microglobulin (β2m), we previously demonstrated that amyloid fibrils and amorphous aggregates form competitively depending on salt (NaCl) concentration. To examine the generality of the underlying competitive mechanisms, we herein investigated the effects of heat on acid-denatured β2m at pH 2. Using thioflavin fluorescence, CD, and light scattering analysis along with atomic force microscopy imaging, we found that the temperature-dependent aggregation of β2m markedly depends on NaCl concentration. Stepwise transitions from monomers to amyloids and then back to monomers were observed at low NaCl concentrations. Amorphous aggregates formed rapidly at ambient temperatures at high NaCl concentrations, but the transition from amorphous aggregates to amyloids occurred only as the temperature increased. Combining the data from the temperature- and NaCl-dependent transitions, we constructed a unified phase diagram of conformational states, indicating a parabolic solubility curve with a minimum NaCl concentration at ambient temperatures. Although amyloid fibrils formed above this solubility boundary, amorphous aggregates dominated in regions distant from this boundary. Kinetic competition between supersaturation-limited slow amyloid fibrillation and supersaturation-unlimited fast amorphous aggregation deformed the phase diagram, with amyloid regions disappearing with fast titration rates. We conclude that phase diagrams combining thermodynamics and kinetics data provide a comprehensive view of β2m aggregation exhibiting severe hysteresis depending on the heat- or salt-titration rates.

Haloplanus rallus sp. nov., a halophilic archaeon isolated from crude solar salt.

A halophilic archaeon, strain MBLA0036T, was isolated from Sorae solar saltern near Incheon, Republic of Korea. Strain MBLA0036T had three 16S rRNA genes: rrnA, rrnB and rrnC. The 16S rRNA gene sequence similarities between strain MBLA0036T (based on the rrnA gene) and Haloplanus ruber R35T and Haloplanus litoreus GX21T were 98.0 and 97.3 %, respectively. The similarities of the RNA polymerase subunit B' gene between strain MBLA0036T and H. ruber R35T and H. litoreus GX21T were 94.0 and 92.1 %, respectively. Cells of strain MBLA0036T were Gram-stain-negative, motile, red-pigmented, pleomorphic, flat and contained gas vesicles. Strain MBLA0036T grew at 15‒55 °C (optimum, 37 °C), in 10‒30 % (w/v) NaCl (15 %, w/v) with 0‒0.5 M MgSO4.7H2O (0.2 M) and at pH 6.0-9.0 (pH 7.0). The cells lysed in distilled water and the minimum NaCl concentration that prevented cell lysis was 5 % (w/v). Major polar lipids of strain MBLA0036T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a glycolipid that was chromatographically identical to sulfated mannosyl glucosyl diether. The major isoprenoid quinone was menaquinone-8. The genomic DNA G+C content was 65.5 mol%. DNA-DNA hybridization values between strain MBLA0036T and H. ruber JCM 17271T and H. litoreus JCM 17092T were 35±3 and 18±1 %, respectively. Therefore, strain MBLA0036T is described a novel species of the Haloplanus, for which we propose the name Haloplanusrallus sp. nov. The type strain is MBLA0036T (=KCTC 4239T=JCM 31425T).

Salinirubellus salinus gen. nov., sp. nov., isolated from a marine solar saltern.

A halophilic archaeal strain, designated ZS-35-S2T, was isolated from Zhoushan marine solar saltern in Zhejiang Province, China. Cells were pleomorphic, Gram-stain-negative and formed red-pigmented colonies on agar plates. The cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). Strain ZS-35-S2T was able to grow at 25-50 °C (optimum, 37 °C), with 1.4-4.8 M NaCl (optimum, 2.1 M), with 0-1.0 M MgCl2 (optimum, 0.1 M) and at pH 5.0-9.5 (optimum, pH 7.5). Phylogenetic tree reconstructions based on 16S rRNA genes and rpoB' genes revealed that strain ZS-35-S2T was distinct from the related genera Halomarina, Natronomonas, Halorientalis, Salinirubrum and Halobaculum of the order Halobacteriales. The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and three unidentified glycolipids. The two major glycolipids were chromatographically identical to S-DGD-1 and DGD-1, respectively. The DNA G+C content of strain ZS-35-S2T is 67.0 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain ZS-35-S2T (=CGMCC 1.12551T=JCM 30036T) represents a novel species of a new genus within the order Halobacteriales, for which the name Salinirubellus salinus gen. nov., sp. nov. is proposed.

Halobacterium litoreum sp. nov., isolated from a marine solar saltern.

Halophilic archaeal strain ZS-54-S2T was isolated from Zhoushan marine solar saltern, China. Cells were rod-shaped, Gram-stain-negative and formed red-pigmented colonies on an agar plate. Strain ZS-54-S2T was able to grow at 20-50 °C (optimum 35 °C), at 1.7-4.8 M NaCl (optimum 3.9 M), at 0.005-1.0 M MgCl2 (optimum 0.05 M) and at pH 5.0-9.5 (optimum pH 7.0). The cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was found to be 5 % (w/v). The major polar lipids of the strain were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, two glycolipids, which were chromatographically identical to sulfated galactosyl mannosyl galactofuranosyl glucosyl diether and galactosyl mannosyl glucosyl diether, and an unidentified glycolipid, which was chromatographically identical to one detected in Halobacterium salinarum ATCC 33171T. The 16S rRNA gene and rpoB' gene of strain ZS-54-S2T were phylogenetically related to the corresponding genes of Halobacterium noricense JCM 15102T (97.5 % and 90.6 % relatedness, respectively), Halobacterium jilantaiense CGMCC 1.5337T (96.9 and 91.2 %), Halobacterium rubrum CGMCC 1.12575T (96.8 and 90.3 %) and Halobacterium salinarum CGMCC 1.1958T (96.5 and 88.4 %). The DNA G+C content of strain ZS-54-S2T was 66.7 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain ZS-54-S2T (=CGMCC 1.12562T=JCM 30038T) represents a new species of Halobacterium, for which the name Halobacteriumlitoreum sp. nov. is proposed.

Salinirussus salinus gen. nov., sp. nov., isolated from a marine solar saltern.

A halophilic archaeal strain, YGH44T, was isolated from the Yinggehai marine solar saltern in Hainan Province of China. Cells were rod-shaped, stained Gram-negative and formed red-pigmented colonies on agar plates. Optimal growth was obtained with 3.4 M NaCl (range: 2.6-4.8 M), 0.5 M MgCl2 (range: 0.005-1.0 M), at 37 °C (range: 25-55 °C) and at pH 7.0 (range: pH 5.0-9.0). The cells lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was 1.7 M. Phylogenetic tree reconstructions based on 16S rRNA genes and rpoB' genes revealed that strain YGH44T was distinct from the related genera, Halovenus, Halapricum, Halorientalis, Halorhabdus and Halosimplex of the order Halobacteriales. The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and three unidentified glycolipids. The DNA G+C content of strain YGH44Twas 69.0 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YGH44T (=CGMCC 1.12234T=JCM 18646T) represents a novel species of a new genus within the order Halobacteriales, for which the name Salinirussus salinus gen. nov., sp. nov. is proposed.

Natronoarchaeum persicum sp. nov., a haloarchaeon isolated from a hypersaline lake.

A novel halophilic archaeon, designated strain WIIAL99T, was isolated from Lake Meyghan, a hypersaline lake in Iran. Cells of strain WIIAL99T were non-motile, catalase-positive and oxidase-negative. Strain WIIAL99T required at least 2.5 M NaCl and 0.05 M MgCl2 for growth. Optimal growth was achieved at 3.5 M NaCl and 0.1 M MgCl2. The optimum pH and temperature for growth were pH 7.0 and 37-40 °C; it was able to grow at pH 6.0-8.5 and 20-55 °C. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of strain WIIAL99T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, disulfated diglycosyl diether and one unidentified glycolipid. The DNA G+C content of strain WIIAL99T was 66.7 mol%. The closest relative was Natronoarchaeum rubrum JCM 17119T with 98.2 % similarity in the orthologous 16S rRNA gene sequence. Analysis of 16S rRNA and rpoB' gene sequences indicated that strain WIIAL99T is a member of the genus Natronoarchaeum in the family Halobacteriaceae and forms a distinct cluster. It was concluded that strain WIIAL99T (=IBRC-M 11062T=LMG 29814T) represents a novel species of the genus Natronoarchaeum, for which the name Natronoarchaeum persicum sp. nov. is proposed.

Halomarina rubra sp. nov., isolated from a marine solar saltern.

Halophilic archaeal strain ZS-47-ST was isolated from Zhoushan marine solar saltern, China. Cells were pleomorphic, stained Gram-negative, and formed red-pigmented colonies on agar plate. Strain ZS-47-ST was able to grow at 20-50°C (optimum 37°C), at 0.9-4.8M NaCl (optimum 3.4M), at 0.005-1.0M MgCl2 (optimum 0.03M), and at pH 5.5-9.5 (optimum pH 6.5-7.5). The cells lysed in distilled water and the minimal NaCl concentration to prevent cell-lysis was 5% (w/v). The major polar lipids were C20C20 and C20C25 diether derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, glucosyl mannosyl glucosyl diether, and three unidentified glycolipids. The 16S rRNA gene and rpoB' gene of strain ZS-47-ST were phylogenetically related to the corresponding genes of Halomarina oriensis JCM 16495T (98.57 and 92.94% similarities, respectively) and Halomarina salina CGMCC 1.12543T (97.96 and 93.65% similarities, respectively). The DNA G+C content of strain ZS-47-ST was 64.6mol% (T m). The phenotypic, chemotaxonomic, and phylogenetic properties suggested that strain ZS-47-ST (=CGMCC 1.12563T=JCM 30037T) represents a new species of Halomarina, for which the name Halomarina rubra sp. nov. is proposed.

Halorussus salinus sp. nov., isolated from a marine solar saltern.

A halophilic archaeal strain YJ-37-HT was isolated from Yangjiang marine solar saltern, China. Cells were pleomorphic rods, stained Gram negative and formed red-pigmented colonies on agar plate. Strain YJ-37-HT was able to grow at 20-50°C (optimum 37°C), at 0.9-4.8M NaCl (optimum 2.6M NaCl), at 0-1.0M MgCl2 (optimum 0.3 MgCl2) and at pH 6.5-9.0 (optimum pH 7.0). The cells lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5% (w/v). The 16S rRNA gene and rpoB' gene of strain YJ-37-HT were phylogenetically related to the corresponding genes of Halorussus members (93.2-95.8% and 90.1-93.9% similarities, respectively). The major polar lipids of the strain were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and five glycolipids, sulfated galactosyl mannosyl glucosyl diether (S-TGD-1), galactosyl mannosyl glucosyl diether (TGD-1), sulfated mannosyl glucosyl diether (S-DGD-1), mannosyl glucosyl diether (DGD-1) and diglycosyl diether (DGD-2). The DNA G+C content of strain YJ-37-HT was 64.9mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-37-HT (=CGMCC 1.12571T=JCM 30032T) represents a new species of Halorussus, for which the name Halorussus salinus sp. nov. is proposed.

Halomarina salina sp. nov., isolated from a marine solar saltern.

A halophilic archaeal strain, designated ZS-57-S(T), was isolated from Zhoushan marine solar saltern, China. Cells were observed to be pleomorphic, stained Gram-negative and formed red pigmented colonies on agar plates. Optimal growth was obtained at 3.9M NaCl (range 1.4-4.8M), 0.3M MgCl2 (range 0-1.0M), 30°C (range 20-55°C) and pH 6.5-7.5 (range 5.5-9.0). The cells were found to lyse in distilled water and the minimal NaCl concentration to prevent cell lysis was determined to be 5% (w/v). The major polar lipids were identified as C20C20 and C20C25 diether derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, glucosyl mannosyl glucosyl diether and two unidentified glycolipids. The 16S rRNA gene and rpoB' gene of strain ZS-57-S(T) were phylogenetically related to the corresponding genes of Halomarina oriensis JCM 16495(T) (98.2 and 93.7% similarities, respectively). The DNA G+C content of strain ZS-57-S(T) was determined to be 67.1mol% (T m). The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain ZS-57-S(T) (=CGMCC 1.12543(T)=JCM 30039(T)) represents a new species of the genus Halomarina, for which the name Halomarina salina sp. nov. is proposed.

Salinigranum salinum sp. nov., isolated from a marine solar saltern.

An extremely halophilic archaeal strain YJ-50-S2T was isolated from Yangjiang marine solar saltern, China. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on agar plates. Strain YJ-50-S2T was able to grow at 25-50 °C (optimum 37 °C), with 0.9-4.8 M NaCl (optimum 2.6 M NaCl) and 0-1.0 M MgCl2 (optimum 0.03 M MgCl2), and at pH 5.0-9.5 (optimum pH 7.5). The cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 5 % (w/v). The 16S rRNA gene and rpoB' gene of strain YJ-50-S2T were phylogenetically related to the corresponding genes of Salinigranum rubrum GX10T (97.0 % and 90.5 % similarities, respectively). The major polar lipids of strainYJ-50-S2T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and two major glycolipids chromatographically identical to sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. Several unidentified glycolipids were also detected. The DNA G+C content of strain YJ-50-S2T was 65.2 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-50-S2Trepresents a novel species of the genus Salinigranum, for which the name Salinigranum salinum sp. nov. is proposed. The type strain is YJ-50-S2T (=CGMCC 1.12572T=JCM 30033T).

Halorubrum rutilum sp. nov. isolated from a marine solar saltern.

A halophilic archaeal strain, YJ-18-S1(T), was isolated from Yangjiang marine solar saltern, Guangxi Province, China. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on agar plates. Strain YJ-18-S1(T) was able to grow at 20-55 °C (optimum 37 °C), at 0.9-4.8 M NaCl (optimum 2.6 M NaCl), at 0.005-1.0 M MgCl2 (optimum 0.3 MgCl2) and at pH 5.5-8.5 (optimum pH 7.0). The cells were lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5 % (w/v). The major polar lipids of the strain were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The 16S rRNA gene and rpoB' gene of strain YJ-18-S1(T) were phylogenetically related to the corresponding genes of Halorubrum members (94.3-98.0 and 86.7-96.1 % similarities, respectively). The DNA G+C content of strain YJ-18-S1(T) was 66.2 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-18-S1(T) (=CGMCC 1.12554(T) = JCM 30030(T)) represents a new species of Halorubrum, for which the name Halorubrum rutilum sp. nov. is proposed.

Halorussus amylolyticus sp. nov., isolated from an inland salt lake.

A halophilic archaeal strain, YC93T, was isolated from Yuncheng salt lake in Shanxi Province, China. Cells were pleomorphic rods, stained Gram-negative and formed light-red-pigmented colonies on agar plates. Strain YC93T was able to grow at 25–50 °C (optimum 37 °C), with 1.4–4.8 M NaCl (optimum 2.0 M), with 0–1.0 M MgCl2 (optimum 0.05 M) and at pH 6.0–9.5 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). 16S rRNA gene sequence analysis revealed that strain YC93T had two dissimilar 16S rRNA genes both of which were phylogenetically related to those of the two recognized members of the genus Halorussus (93.0–95.3 % similarity). The rpoB′ gene of strain YC93T was phylogenetically related to the corresponding gene of Halorussus rarus TBN4T (91.3 % similarity) and Halorussus ruber YC25T (90.5 %). The major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and five glycolipids chromatographically identical to those of Halorussus rarus CGMCC 1.10122T. The DNA G+C content of strain YC93T was 64.6 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC93T represents a novel species of the genus Halorussus, for which the name Halorussus amylolyticus sp. nov. is proposed. The type strain is YC93T ( = CGMCC 1.12126T = JCM 18367T).

Haloarchaeobius amylolyticus sp. nov., isolated from a marine solar saltern.

Halophilic archaeal strain XD48(T) was isolated from a Chinese marine solar saltern. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on solid media. Strain XD48(T) was found to be able to grow at 25-50 °C (optimum 37 °C), at 0.9-4.8 M NaCl (optimum 3.1 M NaCl), at 0-1.0 M MgCl2 (optimum 0.3 MgCl2) and at pH 5.0-9.5 (optimum pH 6.5). The cells lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5% (w/v). The major polar lipids of the strain were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS), sulfated galactosyl mannosyl glucosyl diether (S-TGD-1), sulfated mannosyl glucosyl diether (S-DGD-1) and six unknown glycolipids. The 16S rRNA gene and rpoB' gene of strain XD48(T) were phylogenetically related to the corresponding genes of Haloarchaeobius members (92.4-93.9 and 89.6-90.5% similarities, respectively). The DNA G + C content of strain XD48(T) was determined to be 65.3 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain XD48(T) (=CGMCC 1.12230(T) = JCM 18642(T)) represents a new species of Haloarchaeobius, for which the name Haloarchaeobius amylolyticus sp. nov. is proposed.