Salt Lake In China Research Articles

Characterization and Resource Potential of Li in the Clay Minerals of Mahai Salt Lake in the Qaidam Basin, China

The strategic importance of lithium in global development has become increasingly prominent due to the rapid growth of the new energy automotive industry and the continuous advancements in controllable nuclear fusion technology. Lithium minerals in salt lakes possess advantageous characteristics, such as abundant reserves, environmental sustainability, and economic viability. Furthermore, with ongoing improvements in the lithium extraction process, the availability of lithium minerals in salt lakes is expected to further increase. The Qaidam Basin Salt Lake in China has served as the location for the establishment of numerous lithium carbonate production enterprises, resulting in a lithium carbonate production volume of 7 × 104 t/yr in 2022. How to meet the growing need for lithium resources has become an enterprise focus. Nevertheless, there are large amounts of clay minerals in and around the bottom and periphery of the salt lake in the Qaidam Basin, and whether these minerals are of exploitable value, regardless of the state of the occurrence of lithium resources, remains unexplored. To ascertain the attributes, extent, and distribution of the lithium occurrence within the clayey layer of the Qaidam Basin, as well as to assess its resource potential, a total of 87 drill holes were conducted within a designated area of the Mahai Basin, which is a secondary basin in the Qaidam Basin. The subsequent analysis encompassed the examination of the lithium content within the clay minerals, the mineral composition of the clay, and, ultimately, the evaluation of the resource potential within the region. Compared with Quaternary salt lake deposits, brine deposits in gravel pores, and the Paleogene–Neogene Li-bearing salt deposits that have been studied, it is suggested that this is a novel form of a clay-type sedimentary Li deposit within the Qaidam Basin. The findings of this research will serve as a fundamental basis for future endeavors pertaining to the exploration and exploitation of lithium deposits within salt lake areas.

Multiple evaluations, risk assessment, and source identification of heavy metals in surface water and sediment of the Golmud River, northeastern Qinghai-Tibet Plateau, China

The water quality of the Golmud River is essential for environmental preservation and economic growth of Golmud city and Qarhan Salt Lake in China. Thirty-four samples of surface water and sediment from seventeen places in the Golmud River and thirty-two dustfall samples in the Qaidam Basin were collected. The concentrations of heavy metals (HMs) were measured; water quality, risk assessment, and multiple source analysis were applied. Concentrations of HMs in water were Zn > Cu > Ni > As > Pb > Cd > Hg, and in sediment were Ni > Zn > Pb > As > Cu > Cd > Hg. In water, the Nemerow pollution index (NP) values indicated that most of the sampling points seemly were seriously polluted; other water quality assessment results suggested no pollution. In sediment, the concentrations of 27% HMs exceeded the background values of soil in Qinghai; 48% exceeded the Earth crust background values, which were As, Hg, and Cd. The single factor index method (Pi), geological accumulation index (Igeo), and contamination factor (CF) revealed that As pollution is serious, followed by Hg and Cd; the pollution load index (PLI) and modified pollution index (mCd) values indicated that 64% and 57% of samples were polluted. NP values are shown serious pollution. The ecological risk results demonstrated a low risk in water and a medium risk in sediment. The average total hazard quotient values in sediment and water for adults and children revealed low non-carcinogenic risks. Carcinogenic risk indicated Ni in water and sediment, and As in sediment may be involved in cancer risk. Multivariate statistics showed that the HMs mainly came from nature, and human activities will also impact them. The upper continental crust values indicated that As and Hg have high background values. The saline dust storm was one of the essential sources of HMs, especially Hg. Various provenances constituted the material cycling of HMs in the surface environment.

Preparation and characterization of high-stability lithium ion-sieves with aluminosilicate framework

The ion exchange adsorption method is the most promising technique for lithium recovery from low-grade brines, and the main adsorbents are titanium-based and manganese-based ion-sieves. Their expensive cost and poor cycling performance, which have limited their industrial applications, need to be solved fundamentally by finding a new ion-sieve. Hence, in this work, a high-stability and low-priced lithium ion-sieve with aluminosilicate framework was successfully synthesized by solid-phase sintering. The cheap silicon and aluminum raw materials make this ion-sieve have a low synthesis cost. The adsorption behavior of ion-sieves fits the Langmuir model and pseudo-second-order kinetics, indicating that the adsorption of lithium is mainly monolayer adsorption, and the process is chemisorption. After ten cycles, the lithium adsorption capacity is still over 27 mg/g. Moreover, it can recover lithium in the brine of West Taijinar Salt Lake in China even at 160 °C due to the excellent stability of the aluminosilicate framework, which can effectively improve its industrial production efficiency. Therefore, it has great potential to extract lithium from liquid lithium resources with a high Mg/Li ratio.

Eco-friendly extraction of magnesium and lithium from salt lake brine for lithium-ion battery

The composition of salt lake brine is complex, and the physical and chemical properties of Mg and Li are very close to each other, which is difficult to separate. In this paper, a new type of nanomaterial is developed based on the salt lake brine, and the Qinghai salt lake in China is used as the model. The solar evaporation-acid leaching-diaphragm electrolytic doping strategy is used to successfully separate Li and Mg. A composite metal self-supporting material is constructed during the electrodeposition process, and finally prepared MgZnCe(OH)8 and its oxide MgZnCeO4 are used as anode materials, and LiPF6 is used as electrolyte. Electrochemical tests show that at a current density of 200 mA/g, the initial charge and discharge capacity are 38.71 (274.33) and 76.41 (138.78) mAh/g, but after many cycles, the capacity is steadily increased, the charge and discharge capacity is almost equal, the coulombic efficiency is as high as 100%. In particular, the MgZnCeO4 negative electrode has an increase of nearly 3.41 (1.45) times compared with the first cycle of charge and discharge capacity after 3000 cycles. This excellent lithium storage performance is attributed to the macroscopic design of the composite metal supporting negative electrode. The special alloying reaction, Mg2+ substitution reaction, more stable spatial structure and smooth Li+ transmission channel can effectively improve the volume change, and also accelerate the lithium/dilithium dynamics.

The Identification and Geological Significance of Fault Buried in the Gasikule Salt Lake in China based on the Multi‐source Remote Sensing Data

AbstractThe salinity of the salt lake is an important factor to evaluate whether it contains some mineral resources or not, the fault buried in the salt lake could control the abundance of the salinity. Therefore, it is of great geological importance to identify the fault buried in the salt lake. Taking the Gasikule Salt Lake in China for example, the paper established a new method to identify the fault buried in the salt lake based on the multi‐source remote sensing data including Landsat TM, SPOT‐5 and ASTER data. It includes the acquisition and selection of the multi‐source remote sensing data, data preprocessing, lake waterfront extraction, spectrum extraction of brine with different salinity, salinity index construction, salinity separation, analysis of the abnormal salinity and identification of the fault buried in salt lake, temperature inversion of brine and the fault verification. As a result, the study identified an important fault buried in the east of the Gasikule Salt Lake that controls the highest salinity abnormal. Because the level of the salinity is positively correlated to the mineral abundance, the result provides the important reference to identify the water body rich in mineral resources in the salt lake.

Enriching lithium and separating lithium to magnesium from sulfate type salt lake brine

Extraction of lithium from salt lake brine has become a research highlights due to the rapid development of lithium ion battery. There are abundant lithium resources in sulfate type salt lake in China. In this work, the process of enriching lithium and separating lithium to magnesium from simulated sulfate type brine was carried out based on the reaction of Al/Na2SO4 composite with brine. The results show that Al/Na2SO4 composite can be used to enrich lithium from Li2SO4 solution in the form of Li2Al4(OH)12SO4·xH2O and the lithium precipitation efficiency reaches 89.2% under the optimal conditions. The existence of magnesium in solution is adverse to the precipitation process of lithium. The coating of compact MgAl hydrotalcite on the surface of aluminum based material hinders the reaction of Al/Na2SO4 composite with brine and the lithium precipitation efficiency decreases to 54.7% when the Mg/Li mass ratio in solution is 20:1. However, the Mg/Li mass ratio in precipitate is less than 0.3 under the optimal conditions. The results are beneficial for the enriching lithium and separating lithium to magnesium from sulfate type brine.

Aidingimonas lacisalsi sp. nov., isolated from a salt lake in China.

A novel bacterium, XHU 5135T, belonging to the genus Aidingimonas, was isolated from a salt lake sample collected in Xinjiang Province, north-west PR China. The isolate was Gram-stain-negative, rod-shaped and non-motile. The strain was catalase-positive and oxidase-negative. Growth occurred at NaCl concentrations of 5-25 % (optimum, 10-13 %), at 13-41 °C (35-37 °C) and at pH 6.0-10.0 (pH 7.0-8.0). The predominant ubiquinone was Q-9. The major fatty acids were C19 : 0 cyclo ω8c and C16 : 0. The G+C content of the genomic DNA was 58.1 mol%. The affiliation of strain XHU 5135T with the genus Aidingimonas was confirmed by 16S rRNA gene sequence comparisons. The closest type strain was Aidingimonas halophile YIM 90637T, which showed a 16S rRNA gene sequence similarity of 97.5 %. The ANI value between XHU 5135T and the closest type strain was 80.01 %. The estimated digital DNA-DNA hybridization estimate value between strain XHU 5135T and the closest type strain was 22.80 %. Phenotypically, the characteristics of XHU 5135T were shown to differ from the most closely related species, A. halophila. On the basis of the data from this polyphasic study, strain XHU 5135T represents a novel species of the genus Aidingimonas, for which the name Aidingimonas lacisalsi sp. nov. is proposed. The type strain is strain XHU 5135T (=CCTCC AB 2016344T=KCTC 42945T=DSM 104700T).

Thermal Equilibrium and Energy Conversion of a New Photoreceptor with Two Chromophores as Studied by In Situ Spectroscopy

Archaerhodopsin-4 (aR4), an unknown structured membrane protein from Halobacterium species XZ515 found in a salt lake in China, functions as a proton pump similar to that of bacteriorhodopsin (bR). It has a seven-transmembrane topology and a protonated Schiff base formed by the retinal chromophore with the lysine 217 on the helix G through a covalent bond linkage. Absorption of a photon causes photoisomerization of the retinal chromophore from the all-trans to the 13-cis, 15-anti configuration and triggers a series of structural rearrangements of the protein that initiates a vectorial translocation of a proton out of the cell. aR4 has not only a retinal as the premier chromophore, but also a bacterioruberin as the second chromophore. Furthermore, aR4 has an opposite temporal order of proton uptake and release at neutral pH as compared with bR. In order to elucidate how the retinal cis-trans thermal equilibrium is maintained and modulated by the second chromophore, and further affect the proton uptake and release order, the photocycle kinetics, and the energy conversion efficiency in the claret membrane, in situ 2D solid-state NMR of the specifically labelled receptors in the claret membranes, reinforced with many single point mutation analyses and function assays were carried out. Hydrogen bonding and hydrophobic interactions were identified as the mechanistic origin of multiple outcomes, including direct electromechanical coupling to the dynamics of conformational changes within the receptor, direct monomer interactions, and energy conversion efficiency in native membranes. These new insights may be generalized to other receptors and proteins in which metastable thermal equilibria have been identified and perturbed by ligand binding and downstream signaling.

Aidingibacillus halophilus gen. nov., sp. nov., a novel member of the family Bacillaceae.

A Gram-positive, non-motile, asporogenous and aerobic bacterium, designated YIM 98012T, was isolated from a salt lake in China. Strain YIM 98012T was found to be catalase and oxidase positive. Optimal growth of strain YIM 98012T was observed at 37°C and pH 7.0 and it was found to grow in the presence of 5-20% (w/v) NaCl (optimum 10% NaCl). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the novel strain is affiliated with the family Bacillaceae of the phylum Firmicutes and that it shares high (94.7%) sequence similarity with Alteribacillus persepolensis DSM 21632T and does not show sequence similarities of more than 94.0% to known members of other related genera. The major fatty acids (>10%) were identified as anteiso-C15:0, anteiso-C17:0, iso-C16:0 and C16:0. The genomic DNA G+C content was determined to be 41.0mol% and the dominated respiratory quinone was identified as MK-7. The cell wall peptidoglycan of strain YIM 98012T was found to contain meso-diaminopimelic acid, while the polar lipids profile was found to include diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. Based on physiological and chemotaxonomic characteristics, strain YIM 98012T is concluded to be the type strain of the type species of a novel genus in the family Bacillaceae for which the name Aidingibacillus halophilus gen. nov., sp. nov. is proposed. The type strain is YIM 98012T (=KCTC 33868T=DSM 104332T).

Description of Salilacibacter albus gen. nov., sp. nov., isolated from a dried salt lake, and reclassification of Paraglycomyces xinjiangensis Luo et al. 2015 as a later heterotypic synonym of Salininema proteolyticum Nikou et al. 2015 with emended descriptions of the genus Salininema and Salininema proteolyticum.

A novel halophilic actinomycete, designated strain J11Y309T, was isolated from a soil sample collected from a dried salt lake in China. This isolate grew optimally at 28‒37 °C, with 3‒5 % (w/v) NaCl and at pH 7.0‒7.5. It contained meso-diaminopimelic acid as the diagnostic diamino acid and glucose, ribose and xylose were present in the whole-cell hydrolysates. MK-10(H4) was detected as the predominant menaquinone. The major fatty acids were anteiso-C17 : 0, iso-C16 : 0, iso-C17 : 0 and iso-C15 : 0. Polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, phosphoglycolipids, glycolipids, an unidentified phospholipid and additional unidentified lipids. The G+C content of the genomic DNA was 63.0 mol%. The novel strain shared highest 16S rRNA gene sequence similarity with Salininema proteolyticum Miq-4T (95.80 %), Paraglycomyces xinjiangensis TRM 49201T (95.77 %) and Haloglycomyces albus YIM 92370T (94.84 %). Phylogenetic trees showed that it could not be clearly assigned to any known genus within the family Glycomycetaceae and formed a distinct phylogenetic line in the clade comprising members of the genera Salininema, Paraglycomyces and Haloglycomyces. Based on data from the present polyphasic taxonomic study, strain J11Y309T represents a novel species of a new genus in the family Glycomycetaceae, for which the name Salilacibacter albus gen. nov., sp. nov. is proposed with Salilacibacter albus sp. nov. as the type species. The type strain of Salilacibacter albus is J11Y309T (=DSM 46875T=CGMCC 4.7242T=LMG 29297T). Reclassification of Paraglycomyces xinjiangensis Luo et al. 2015 as a later heterotypic synonym of Salininema roteolyticum Nikou et al. 2015 is also discussed in this study.

Techniques of Preventing Subgrade from Salinization for Qarham to Golmud Expressway

Qarham to Golmud expressway is the first high-grade road in Qarham salt lake, which is regarded as the most enormous inland salt lake in China, moreover, it is the first expressway built on the inland salt lake in China. There is high and excessive saline soil distributed over this area whose thickness is no less than 20m, but the average subgrade height of the expressway is only 2m. A great many of measures are taken for the construction of the subgrade to prevent salt migrating from foundation to roadbed and pavement, which will cause disasters of secondary salinization in roadbed and pavement. By paving testing road at the site and detecting the efficiency of the measures in preventing salt, the paper put forward the technique of preventing subgrade from salinization for Qarham to Golmud expressway. The results of testing and detecting demonstrate that the height of salt migration is only 45cm in subgrade under the condition of brine supply, which is less than the height of subgrade. So it is efficient to keep the roadbed and pavement from the erosion of salt; The settlement of road surface was about 0~2mm among 3 months since the highways had been opened to traffic for two years, and uneven settlement and other diseases caused by the secondary salinization were not appeared, which showed that the measures of salinization prevention (salt resistance) were taken well to achieve the design purposes.

Halobellus inordinatus sp. nov., from a marine solar saltern and an inland salt lake of China

Two halophilic archaeal strains, YC20(T) and XD15, were isolated from a marine solar saltern and an inland salt lake in China. Both had pleomorphic cells that lysed in distilled water, stained Gram-negative and formed red-pigmented colonies. They were neutrophilic, requiring at least 100 g NaCl l(-1) and 0.5-95 g MgCl2 l(-1) for growth at the optimum growth temperature of 37 °C. The major polar lipids of the two strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and two major glycolipids chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1) and mannosyl glucosyl diether (DGD-1), respectively. Trace amounts of two unidentified glycolipids were also detected. The 16S rRNA gene sequences of the two strains were 99.5 % identical and showed 94.0-95.9 % similarity to the most closely related members of the genus Halobellus of the family Halobacteriaceae. The rpoB' gene sequence similarity between strains YC20(T) and XD15 was 98.2 % and these sequences showed 89.6-92.8 % similarity to those of the most closely related members of the genus Halobellus. The DNA G+C contents of strains YC20(T) and XD15 were 65.8 mol% and 65.4 mol%, respectively. The DNA-DNA hybridization value between strain YC20(T) and strain XD15 was 92 %, and the two strains showed low DNA-DNA relatedness to members of the genus Halobellus. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains YC20(T) and XD15 represent a novel species of the genus Halobellus, for which the name Halobellus inordinatus sp. nov. is proposed. The type strain is YC20(T) ( = CGMCC 1.12120(T) = JCM 18361(T)) and the other strain is XD15 ( = CGMCC 1.12236 = JCM 18648).

Metagenomic cloning and characterization of Na+/H+ antiporter genes taken from sediments in Chaerhan Salt Lake in China

A metagenomic library containing 8,000 clones was constructed by using genomic DNA obtained from Chaerhan Salt Lake in northwest China. Three Na(+)/H(+) antiporters, C4-NhaG, C47-NhaG and C49-NhaG that grouped to the NhaG family, were screened and cloned from this metagenome by complementing Escherichia coli strain KNabc (ΔnhaA ΔnhaB ΔchaA) in medium containing 0.2 M NaCl. The three putative Na(+)/H(+) antiporters were membrane proteins with 10, 11 and 11 transmembrane segments, respectively. They enabled E. coli KNabc to grow in medium containing 0.2-0.6 M Na(+) or 7-14 mM Li(+). Everted membrane vesicles prepared from E. coli KNabc cells carrying C49-NhaG exhibited Na(+)/H(+) and Li(+)/H(+) antiport activities.

Metagenomic cloning and characterization of Na+ transporters from Huamachi Salt Lake in China

Moderately halophilic bacteria are a kind of extreme environment microorganism that can tolerate moderate salt concentrations ranging from 0.5M to 2.5M. Here, via a metagenomic library screen, we identified four putative Na+ transporters, designated H7-Nha, H16-Mppe, H19-Cap and H35-Mrp, from moderately halophilic community in the hypersaline soil of Huamachi Salt Lake, China. Functional complementation observed in a Na+(Ca2+)/H+ antiporter-defective Escherichia coli mutant (KNabc) suggests that the four putative Na+ transporters could confer cells a capacity of Na+ resistance probably by enhancing Na+ or Ca2+ efflux, but not Li+ or K+ exchange. Blastp analysis of the deduced amino-acid sequences indicates that H7-Nha has 71% identity to the NhaG Na+/H+ antiporter of Bacillus subtilis, while H19-Cap shows 99% identity to Enterobacter cloacae Ca2+ antiporter. Interestingly, H16-Mppe shares 59% identity to the metallophosphoesterase of Bacillus cellulosilyticus and H35-Mrp shows 68% identity to multidrug resistance protein of Lysinibacillus sphaericus. This is the first report that predicts a potential role of metallophosphoesterase in Na+ resistance in halophilic bacteria. Furthermore, everted membrane vesicles prepared from E. coli cells harboring H7-Nha exhibit Na+/H+ antiporter activity, but not Li+ (K+)/H+ antiporter activity, confirming that H7-Nha supports Na+ resistance mainly via Na+/H+ antiport. Our report also demonstrates that metagenomic library screen is a convenient and effective way to explore more novel types of Na+ transporters.

Metagenome Cloning and Functional Analysis of Na+/H+ Antiporter Genes from Keke Salt Lake in China

Na⁺/H⁺ antiporters are ubiquitous membrane proteins and play a central role in cell homeostasis including pH regulation, osmoregulation, and Na⁺/Li⁺ tolerance in bacteria. The microbial communities in extremely hypersaline soil are an important resource for isolating Na⁺/H⁺ antiporter genes. A metagenomic library containing 35,700 clones was constructed by using genomic DNA obtained from the hypersaline soil samples of Keke Salt Lake in Northwest of China. Two Na⁺/H⁺ antiporters, K1-NhaD, and K2-NhaD belonging to NhaD family, were screened and cloned from this metagenome by complementing the triple mutant Escherichia coli strain KNabc (nhaA⁻, nhaB⁻, chaA⁻) in medium containing 0.2 M NaCl. K1-NhaD and K2-NhaD have 75.5% identity at the predicted amino acid sequence. K1-NhaD has 78% identity with Na⁺/H⁺ antiporter NhaD from Halomonas elongate at the predicted amino acid sequence. The predicted K1-NhaD is a 53.5 kDa protein (487 amino acids) with 13 transmembrane helices. K2-NhaD has 73% identity with Alkalimonas amylolytica NhaD. The predicted K2-NhaD is a 55 kDa protein (495 amino acids) with 12 transmembrane helices. Both K1-NhaD and K2-NhaD could make the triple mutant E. coli KNabc (nhaA⁻, nhaB⁻, chaA⁻) grow in the LBK medium containing 0.2-0.6 M Na⁺ or with 0.05-0.4 M Li⁺. Everted membrane vesicles prepared from E. coli KNabc cells carrying K1-NhaD or K2-NhaD exhibited Na⁺/H⁺ and Li⁺/H⁺ antiporter activities which were pH-dependent with the highest activity at pH 9.5. Little K⁺/H⁺ antiporter activity was also detected in vesicles form E. coli KNabc carrying K1-NhaD or K2-NhaD.

Virgibacillus sediminis sp. nov., a moderately halophilic bacterium isolated from a salt lake in China

A Gram-positive, moderately halophilic, alkalitolerant, strictly aerobic, oxidase- and catalase-positive, rod-shaped bacterium, strain YIM kkny3T, was isolated from a sediment sample collected from a salt lake in the Qaidam Basin of north-west China. Cells were motile by means of peritrichous flagella and formed ellipsoidal endospores lying in subterminal swollen sporangia. Growth occurred with 1-20% (w/v) total salts (optimum, 5-10%) and at pH 6.0-10.5 (optimum, pH 7.5-8.0) and 10-55 degrees C (optimum, 35-40 degrees C). It was unable to grow with NaCl as the only salt. meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The strain contained menaquinone 7 (MK-7) as the predominant respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as polar lipids. The major cellular fatty acids were anteiso-C15:0 and anteiso-C17:0. The DNA G+C content was 40.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM kkny3T belonged to the genus Virgibacillus, and was most closely related to the type strains of Virgibacillus olivae (97.1% similarity), Virgibacillus marismortui (97.0%) and Virgibacillus kekensis (96.8%). Levels of DNA-DNA relatedness between strain YIM kkny3T and the type strains of V. olivae, V. marismortui and V. kekensis were 12.4, 10.6 and 15.7%, respectively. The combination of phylogenetic analysis, genotypic data, phenotypic characteristics and chemotaxonomic differences indicated that strain YIM kkny3T represents a novel species of the genus Virgibacillus, for which the name Virgibacillus sediminis sp. nov. is proposed. The type strain is YIM kkny3T (=CCTCC AA 207023T=DSM 19797T=KCTC 13193T).

Bacillus aidingensis sp. nov., a moderately halophilic bacterium isolated from Ai-Ding salt lake in China

A Gram-positive, halophilic bacterium was isolated from a sediment sample from Ai-Ding salt lake in China. The isolate, designated strain 17-5(T), grew at salinities of 8-33 % (w/v) NaCl (optimally at 12 %, w/v). The genomic DNA G+C content of strain 17-5(T) was 48.1 mol%. The predominant isoprenoid quinone was MK-7(H(2)) and the cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol and an unidentified glycolipid. The major cellular fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(16 : 0) and C(16 : 0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 17-5(T) was a member of the genus Bacillus, being most closely related to Bacillus qingdaonensis JCM 14087(T) (96.0 % sequence similarity) and Bacillus salarius DSM 16461(T) (95.6 %). The levels of 16S rRNA gene sequence similarity with respect to other Bacillus species were less than 91.7 %. Comparative analysis of the 16S rRNA gene sequence data, chemotaxonomy and phenotypic features of the novel isolate and related species of Bacillus indicated that strain 17-5(T) represents a novel species within the genus Bacillus, for which the name Bacillus aidingensis sp. nov. is proposed. The type strain is 17-5(T) (=CGMCC 1.3227(T)=DSM 18341(T)).

Virgibacillus kekensis sp. nov., a moderately halophilic bacterium isolated from a salt lake in China

A Gram-positive, moderately halophilic, motile, strictly aerobic, endospore-forming, oxidase- and catalase-positive, rod-shaped bacterium, strain YIM kkny16(T), was isolated from a saline mud sample collected from the Keke salt lake in the Qaidam Basin, north-west China. This isolate grew in the presence of 0-25 % (w/v) NaCl and at pH 6.0-10.0 and 10-50 degrees C; optimum growth was observed with 10 % (w/v) NaCl and at pH 7.0 and 37 degrees C. Strain YIM kkny16(T) had meso-diaminopimelic acid as the diagnostic diamino acid, MK-7 as the predominant respiratory quinone, with a significant amount of MK-6, and anteiso-C(15 : 0), iso-C(14 : 0) and C(16 : 1)omega7c alcohol as major fatty acids. Major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content was 41.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that strain YIM kkny16(T) was a member of the genus Virgibacillus, exhibiting sequence similarities of 94.9-97.3 % to the type strains of recognized Virgibacillus species. Strain YIM kkny16(T) could be differentiated from recognized Virgibacillus species based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and DNA-DNA hybridization data. On the basis of evidence from this polyphasic study, strain YIM kkny16(T) is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus kekensis sp. nov. is proposed. The type strain is YIM kkny16(T) (=DSM 17056(T)=CGMCC 1.6298(T)).

Bacillus salarius sp. nov., a halophilic, spore-forming bacterium isolated from a salt lake in China

A moderately halophilic bacterium, strain BH169T, capable of growing at salinities of 3-20% (w/v) NaCl was isolated from a saline lake in China. Strain BH169T was strictly aerobic, short-rod-shaped and non-motile (non-flagellated). Its major cellular fatty acids were anteiso-C15:0, anteiso-C17:0, iso-C15:0 and iso-C16:0. The genomic DNA G+C content was about 43 mol% and the predominant quinone was MK-7. The cell-wall peptidoglycan was of the A1gamma type, containing meso-diaminopimelic acid as the diagnostic diamino acid. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a distinct phylogenetic line within the spore-forming rods of the genus Bacillus. The levels of 16S rRNA gene sequence similarity to the type strains of Bacillus species were below 93%. On the basis of phenotypic and molecular properties, strain BH169T (=KCTC 3912T=DSM 16461T) represents the type strain of a novel species within the genus Bacillus, for which the name Bacillus salarius sp. nov. is proposed.

Reclassification of Bacillus haloalkaliphilus Fritze 1996 as Alkalibacillus haloalkaliphilus gen. nov., comb. nov. and the description of Alkalibacillus salilacus sp. nov., a novel halophilic bacterium isolated from a salt lake in China

A spore-forming, halophilic bacterium, designated strain BH163(T), was isolated from a salt lake in China. Cells were motile, strictly aerobic rods that contained type A1gamma peptidoglycan with meso-diaminopimelic acid as the diagnostic diamino acid. The isolate showed Gram- and catalase-positive reactions and formed a terminal endospore with a swollen sporangium. The major cellular fatty acids were anteiso-C(15:0), iso-C(15:0), anteiso-C(17:0) and iso-C(16:0). The genomic DNA G+C content of the strain was 41.0 mol%. Comparative analysis of 16S rRNA gene sequences showed that strain BH163(T) formed a distinct line within the phyletic group classically defined as the genus Bacillus and was most closely related to the taxa [Bacillus] haloalkaliphilus DSM 5271(T) and Filobacillus milosensis DSM 13259(T), with 16S rRNA gene sequence similarities of 95.9 and 94.5%, respectively. On the basis of physiological and molecular properties, it is proposed that [Bacillus] haloalkaliphilus DSM 5271(T) is reclassified in the new genus Alkalibacillus as Alkalibacillus haloalkaliphilus gen. nov., comb. nov. Strain BH163(T) (=KCTC 3916(T)=DSM 16460(T)) was assigned as the type strain of the novel species Alkalibacillus salilacus.