Four new species of Russula from the Xizang Autonomous Region and other provinces of China.

Russula is the largest genus in the Russulales and is widespread throughout the world. Almost all Russula species are known to be ectomycorrhizal with high ecological and edible values, and some are lethal poisonous. In this study, four new species belonging to the subgenus Russula crown clade are identified based on morphological and phylogenetic evidence from the Xizang Autonomous Region and other provinces of China. Morphologically, Russula paragraveolens (sect. Polychromae, subsect. Xerampelinae) is mainly characterised by a cherry red to blood red pileus centre, a reddish orange pileus margin; R. pseudograveolens (sect. Polychromae, subsect. Xerampelinae) is characterised by a violet brown to brownish red pileus centre, a pale red to pastel red pileus margin and short basidia; R. shigatseensis (sect. Flavisiccantes, subsect. Lepidinae) is characterised by a brownish orange to madder red pileus centre, pinkish red pileus margin, and having lateral branches or branches of hyphal terminations in pileipellis; R. yadongensis (sect. Tenellae, subsect. Laricinae) is characterised by a dark purplish red pileus centre with brownish purple tints and having isolated to clustered spines of spore ornamentations. Their distinct taxonomic status is confirmed by the positions of the four new species in both the ITS and 4-locus (nucLSU, mtSSU, rpb2, tef1) phylogenetic trees.

Five New Species of Gymnopilus from Xizang Autonomous Region of China and Surrounding Areas.

The species of Gymnopilus (Hymenogastraceae, Agricales) are commonly recognized as wood-decaying fungi. Certain members of this genus have been identified as psilocybin-producing mushrooms. Gymnopilus exhibits a diverse range and has a global distribution. In this study, a total of seventy-eight specimens were gathered from ten provinces in China. A comprehensive molecular phylogenetic analysis was conducted, employing gene sequences including ITS, nrLSU, nrSSU, rpb1, rpb2, and tef1-α. Additionally, morphological examinations were also carried out. The phylogenetic topology of Gymnopilus from this study generally agreed with previous studies and facilitated the identification of all those specimens. As a result, eleven species, including five newly discovered ones named Gy. gyirongensis, Gy. variisporus, Gy. tomentosiceps, Gy. tenuibasidialis, and Gy. aurantipileatus, were recognized. Significantly, four of the five newly identified species are native to the Xizang Autonomous Region, emphasizing their specialization in this distinctive habitat. This research contributes to our comprehension of Gymnopilus diversity and lays the groundwork for the conservation and sustainable utilization of Gymnopilus resources.

Psychroflexus curvus sp. nov., Psychroflexus longus sp. nov. and Psychroflexus montanilacus sp. nov., isolated from salt lakes on the Tibetan Plateau.

Four Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile strains (CAK1WT, CAK8WT, CAK57W and CCL10WT) were isolated from salt lakes in China. Comparisons based on the 16S rRNA gene sequences showed that the four strains show less than 98.9% similarity to species of the genus Psychroflexus. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that Psychroflexus species are the most closely related neighbours of the four strains. The sequenced draft genome sizes of strains CAK1WT, CAK8WT, CAK57W and CCL10WT were 3.01, 2.95, 3.01 and 3.04 Mbp with G+C contents of 37.3, 35.8, 37.5 and 36.6 %, respectively. The phylogenomic trees reconstructed based on the UBCG and GET_PHYLOMARKERS pipelines all demonstrated that the four strains belong to the genus Psychroflexus. The calculated pairwise orthologous average nucleotide identity based on usearch, digital DNA-DNA hybridization and average amino acid sequence identity values among strains CAK1WT, CAK8WT, CAK57W, CCL10WT and other species of the genus Psychroflexus were equal or lower than 91.1, 43.5 and 92.2%; the values between strains CAK1WT and CAK57W were 98.8, 90.2 and 99.0 %, respectively. The respiratory quinone of the four strains was MK-6. Their major fatty acids were iso-C14 : 0, C15 : 1 ω10c, iso-C15 : 0 and anteiso-C15 : 0. The major polar lipids of the four strains included phosphatidylethanolamine, an unidentified aminolipid and two kinds of unidentified lipids, and only strain CCL10WT contained diphosphatidylglycerol. Based on the above descriptions, strains CAK1WT, CAK8WT, CAK57W and CCL10WT should belong to the genus Psychroflexus and represent three independent novel species, for which the names Psychroflexus curvus sp. nov. (type strain CAK1WT=GDMCC 1.2644T=KCTC 82857T), Psychroflexus longus sp. nov. (type strain CAK8WT=GDMCC 1.2646T=KCTC 82859T) and Psychroflexus montanilacus sp. nov. (type strain CCL10WT=GDMCC 1.2631T=KCTC 82860T) are proposed.

Glyceroglycolipids from the solid culture of Ophiocordyceps sinensis strain LY34 isolated from Tibet of China.

Ophiocordyceps sinensis is a well-known entomogenous fungus with its fruiting bodies or cultural mycelium as food and herbal medicines in Asia. While metabolites which could responsible for its potent pharmaceutical effects has long remained to be elucidated. In this work, chemical investigation on the solid culture of O. sinensis strain LY34 led to the discovery of six digalactosyldiacylglycerols (DGDGS, 1-6) including one new. The structure of compound 1 was determined based on the comprehensive spectra analysis, including NMR, MSn, IR, and chemical derivatisation. Bioactivity studies showed a weak cytotoxicity of compounds 1-6 against 293 T cell and medium anti-inflammatory activity of compounds 1 and 2 on Raw 264.7 cell. The discovery of DGDGs in O. sinensis provides new insight into the pharmacologically active substances.

Salegentibacter lacus sp. nov. and Salegentibacter tibetensis sp. nov., isolated from hypersaline lakes on the Tibetan Plateau.

Two Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile strains (LM13ST and JZCK2T) were isolated from hypersaline lakes in China. The colonies of both strains were yellow-pigmented and convex. Both strains could grow at 4-34 °C, pH 6.5-9.0 and with 1.0-13.0 % (w/v) NaCl. Comparisons based on 16S rRNA gene sequences showed that strains LM13ST and JZCK2T share less than 98.3 % similarity with species of the genus Salegentibacter. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that Salegentibacter species are the most closely related neighbours of strains LM13ST and JZCK2T. The sequenced draft genome sizes of strains LM13ST and JZCK2T are 4.06 and 4.22 Mbp with G+C contents of 37.0 and 37.8 mol%, respectively. The phylogenomic tree reconstructed using the Up-to-date Bacterial Core Gene set pipeline also demonstrated that both strains belong to the genus Salegentibacter. The calculated pairwise average nucleotide identity values and digital DNA-DNA hybridization values between strains LM13ST and JZCK2T and Salegentibacter species were less than 86.4 and 32.0 %, respectively. The respiratory quinone in both strains was MK-6. Their major fatty acids were iso-C12 : 0, iso-C14 : 0, C15 : 1 ω10c, iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and C17 : 1 ω10c. Their major polar lipids included phosphatidylethanolamine, one unidentified lipid and one unidentified aminolipid, but strain LM13ST also contained one more unidentified aminolipid, one more unidentified lipid and one unidentified phospholipid. Combining the above descriptions, strains LM13ST and JZCK2T should represent two independent novel species of the genus Salegentibacter, for which the names Salegentibacter lacus sp. nov. (type strain LM13ST=GDMCC 1.2643T=KCTC 82861T) and Salegentibacter tibetensis sp. nov. (type strain JZCK2T=GDMCC 1.2621T=KCTC 82862T) are proposed.

Proposal to reclassify Aquiflexum aquatile into a novel genus as Cognataquiflexum aquatile gen. nov., comb. nov., and description of Cognataquiflexum nitidum sp. nov. and Cognataquiflexum rubidum sp. nov., isolated from freshwater lakes on the Tibetan Plateau.

Thousands of lakes harbouring different characteristics (pH, salinity, temperature) are located on the Tibetan Plateau, and the mining of microbial resources inhabited in these lakes has great value. Two Gram-stain-negative, aerobic, rod-shaped, non-motile strains (LQ15WT and AIY15WT) were isolated from freshwater lakes on the Tibetan Plateau. Comparisons based on the 16S rRNA gene sequences showed that both strains LQ15WT and AIY15WT share 16S rRNA gene sequence similarities 98.4 % with Aquiflexum aquatile Z0201T, but only about 95.0 % with Aquiflexum balticum DSM 16537T. The 16S rRNA gene sequence similarity between strains LQ15WT and AIY15WT was 98.9 %. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that strains LQ15WT and AIY15WT take A. aquatile Z0201T as their closest neighbour and these three strains form a tight cluster. In the phylogenomic tree, the genus Aquiflexum was splited into two clusters by Mariniradius saccharolyticus. Strains LQ15WT, AIY15WT and A. aquatile Z0201T still formed a close cluster, and A. balticum DSM 16537T and Aquiflexum lacus CUG 91378T formed another cluster. The calculated OrthoANIu, average amino acid identity and digital DNA-DNA hybridization values among strains LQ15WT, AIY15WT, A. aquatile Z0201T, A. balticum DSM 16537T and A. lacus CUG 91378T were less than 91.0, 92.9 and 42.1 %, respectively. The major respiratory quinones of both strains LQ15WT and AIY15WT were MK-7 (32 %) and MK-8 (68 %), and their major fatty acids were iso-C15 : 0, C18 : 1 ω9c, summed feature 3 and summed feature 9. The predominant polar lipids of both strains were phosphatidylethanolamine, unidentified aminophospholipids, unidentified phospholipids and lipids. Strain AIY15WT also contained phosphatidylglycerol and unidentified glycolipid. Considering the distinct phylogenetic relationships and chemotaxonomic characteristics between strains A. aquatile Z0201T and A. balticum DSM 16537T, it is proposed to reclassify A. aquatile into a novel genus Cognataquiflexum gen. nov. as Cognataquiflexum aquatile comb. nov., and strains LQ15WT and AIY15WT should represent two independent novel species of the genus Cognataquiflexum, for which the names Cognataquiflexum nitidum sp. nov. (type strain: LQ15WT=CICC 24711T=JCM 34222T) and Cognataquiflexum rubidum sp. nov. (type strain: AIY15WT=CICC 24708T=JCM 34612T) are proposed.

Distribution of Hydrogen-Producing Bacteria in Tibetan Hot Springs, China.

Investigating the distribution of hydrogen-producing bacteria (HPB) is of great significance to understanding the source of biological hydrogen production in geothermal environments. Here, we explored the compositions of HPB populations in the sediments of hot springs from the Daggyai, Quzhuomu, Quseyongba, and Moluojiang geothermal zones on the Tibetan Plateau, with the use of Illumina MiSeq high-throughput sequencing of 16S rRNA genes and hydA genes. In the present study, the hydA genes were successfully amplified from the hot springs with a temperature of 46-87°C. The hydA gene phylogenetic analysis showed that the top three phyla of the HPB populations were Bacteroidetes (14.48%), Spirochaetes (14.12%), and Thermotogae (10.45%), while Proteobacteria were absent in the top 10 of the HPB populations, although Proteobacteria were dominant in the 16S rRNA gene sequences. Canonical correspondence analysis results indicate that the HPB community structure in the studied Tibetan hot springs was correlated with various environmental factors, such as temperature, pH, and elevation. The HPB community structure also showed a spatial distribution pattern; samples from the same area showed similar community structures. Furthermore, one HPB isolate affiliated with Firmicutes was obtained and demonstrated the capacity of hydrogen production. These results are important for us to understand the distribution and function of HPB in hot springs.

Gulosibacter sediminis sp. nov., isolated from Indian Ocean marine sediment.

A novel Gram-stain-positive, catalase-positive, oxidase-negative, aerobic, non-motile, rod-shaped bacterium, designated strain YIM M12148T, was isolated from a marine sediment sample collected from the Indian Ocean. The strain grew optimally at 28 °C, pH 8.0 and in the presence of 1-3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM M12148T belongs to the genus Gulosibacter, with the highest sequence similarity to Gulosibacter faecalis NBRC 15706T (96.12 %). The cell-wall sugars of strain YIM M12148T were rhamnose, ribose, glucose and mannose. The predominant isoprenoid quinones were MK-8 and MK-9. The polar lipids consisted of major amounts of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown lipid. Major fatty acids (>5 % of the total) of the novel isolate were anteiso-C15 : 0, iso-C15 : 0, iso-C13 : 0 and anteiso-C13 : 0. The genomic DNA G+C content of strain YIM M12148T was 67.15 mol%. On the basis of genotypic and phenotypic data, it is apparent that strain YIM M12148T represents a novel species of the genus Gulosibacter, for which the name Gulosibacter sediminis sp. nov. is proposed. The type strain is YIM M12148T (=KCTC 29660T=DSM 29154T).

Undibacterium crateris sp. nov., isolated from water of crater lake.

A Gram-stain-negative, aerobic, flagellated, non-spore-forming, rod-shaped bacterium, named B2R-29T, was isolated from water collected from a crater lake on Da Hinggan mountain, PR China. Strain B2R-29T was oxidase- and catalase-positive. On the basis of the results of 16S rRNA gene sequence analyses, strain B2R-29T clearly belonged to the family Oxalobacteraceae, class Betaproteobacteria and showed the highest similarity to Undibacterium oligocarboniphilum EM1T (97.4 %) and to the other species of Undibacterium (less than 96.8 %). In the phylogenetic tree, strain B2R-29T formed a clade with U. oligocarboniphilum EM1T and Undibacterium squillarum CMJ-9T, indicating that is a member of the genus Undibacterium. Digital DNA-DNA hybridization and average nucleotide identity analyses were performed and the values between strain B2R-29T and its closely related Undibacterium species were less than 75.1 % and 16.9 %, respectively. The chemotaxonomic data of B2R-29T were as follows: major uniquinone, Q-8; predominant polar lipids, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol; major fatty acids, C16 : 0 and summed feature 3 (C16 : 1 ω7c / C16 : 1 ω6c); predominant polyamines, putrescine, 2-hydroxyputrescine and spermidine. The DNA G+C content was 51.7 mol% from the genomic sequencing data. In accordance with the phenotypic, physiological and chemotaxonomic properties mentioned above, strain B2R-29T represents a novel species of the genus Undibacterium for which the name Undibacterium crateris sp. nov. is proposed. The type strain is B2R-29T (=CGMCC 1.13792T=KCTC 72018T).

Influence of Temperature and Sulfate Concentration on the Sulfate/Sulfite Reduction Prokaryotic Communities in the Tibetan Hot Springs.

The distribution and diversity of sulfate/sulfite reduction prokaryotic (SRP) communities in hot springs from the Quzhuomu and Daggyai Geothermal Zone of Tibetan, China, was reported for the first time. In hot springs that are naturally hyperthermal and anoxic, the sulfur cycle is one of the most active cycles of the elements. The distribution of SRP in response to temperature is of great importance to the understanding of biogeochemical cycling of sulfur in geothermal features. Little is known about the SRP in geothermal zone. In this study, the diversity of SRP was investigated in the sediments from the Daggyai and Quzhuomu geothermal zone using PCR amplification, cloning and sequencing of the dissimilatory sulfite reductase beta subunit gene (dsrB). The abundance of dsrB and 16S rRNA genes, were determined by quantitative polymerase chain reactions. In addition, correlations of the SRP assemblages with environmental factors were analyzed by the aggregated boosted tree (ABT) statistical analysis. The results showed that SRP populations were diverse, but were mainly composed of Desulfobacterales, Desulfovibrionales, Syntrophobacterales, Clostridia and Nitrospirales, and large fraction (25%) of novel sequences have branched groups in the dsrB phylogenetic tree. In Quzhuomu geothermal zone, sulfate-rich hot springs are characterized by thick bacterial mats that are green or red and the SRP populations mainly appear at mid-temperature (50 °C to 70 °C). In low-sulfate hot springs in the Daggyai geothermal zone, although gray or pink streamers are widely formed at 60 °C to 80 °C, they prefer to inhabit in green mat at lower temperature (30 °C to 50 °C). With increasing temperature, the diversity of the dsrB gene at the OTU level (cutoff 97%) decreased, while its relative abundance increased. This result suggests that temperature played an important role in affecting dsrB gene distribution.

Craterilacuibacter sinensis gen. nov. sp. nov., isolated from a crater lake in China.

Two bacterial strains, designated B2N2-7T and B2N2-12, were isolated from Buteha crater lake in the Greater Khingan Mountain of China. The two strains were Gram-stain-negative, non-spore-forming, motile with a single polar flagellum, short rod-shaped bacteria. They were catalase- and oxidase-positive. Optimal growth occurred at 20-25 ℃, at pH 7.5-8.0 and with 0-1.0 % (w/v) NaCl. Based on phylogenomic analysis, strains B2N2-7T and B2N2-12 were assigned to the family Neisseriaceae, and their 16S rRNA gene sequences showed the highest similarities to that of Aquitalea denitrificans 5YN1-3T (<94.2 %). The predominant cellular fatty acids were C16 : 0 and summed feature 3 (comprising C16 : 1ω7c/C16 : 1 ω6c). The major respiratory quinone was ubiquinone 8 (Q-8). The polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), two unidentified aminophospholipids (APL) and some unidentified lipids (L). The genomic DNA G+C content of strain B2N2-7T was 59.4 mol% according to the genomic sequencing result. Based on the phylogenetic, genotypic and chemotaxonomic analyses, the two strains are proposed to represent a novel species of a new genus in the family Neisseriaceae, named Craterilacuibacter sinensis gen. nov., sp. nov. The type strain of Craterilacuibacter sinensis is B2N2-7T (=CGMCC 1.17189T=KCTC 73735T); B2N2-12 (=CGMCC 1.17190=KCTC 72734) is a second strain of the species.

Polymorphobacter arshaanensis sp. nov., containing the photosynthetic gene pufML, isolated from a volcanic lake.

An aerobic, Gram-stain-negative, yellowish, rod-shaped bacterium, designated DJ1R-1T, was isolated from water sample from a volcanic lake, located on Da Hinggan Ling Mountain, PR China. Growth of DJ1R-1T optimally occurred at pH 7.0, at 22-25 °C and with 0-0.5 % (w/v) NaCl concentration. Phylogenetic analysis of 16S rRNA gene sequences indicated that DJ1R-1T was clustered into the genus Polymorphobacter, and showed 96.5 %, 95.9 % and 95.6 % similarities to Polymorphobacter fuscus D40PT, Polymorphobacter multimanifer 262-7T and Polymorphobacter glacialis B555-2T, respectively. The predominant polar lipids were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, three unidentified aminolipids and one unidentified phospholipid. The major fatty acids were summed feature 8 (C18 : 1ω7c / C18 : 1ω6c, 40.0 %), summed feature 3 (C16 : 1ω7c / C16 : 1ω6c, 25.6 %) and C16 : 0 (13.7 %). The respiratory quinone was ubiquinone-10. The DNA G+C content was 65.0 % according to the genomic sequencing results. On the basis of the results of the phylogenetic analysis, physiological and biochemical properties comparisons, DJ1R-1T was proposed to represent a novel species of the genus Polymorphobacter, with the name Polymorphobacter arshaanensis. The type strain is DJ1R-1T (=CGMCC 1.13788T=KCTC 72014T).

Tabrizicola alkalilacus sp. nov., isolated from alkaline Lake Dajiaco on the Tibetan Plateau.

A novel Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium was isolated from Lake Dajiaco on the Tibetan Plateau. Strain DJCT grew without NaCl and tolerated up to 3 % (w/v) NaCl. Growth occurred at pH 6.0-10.0 (optimum, pH 7.0-8.0) and 15-37 °C (optimum, 25-30 °C). Vitamins were not required for growth. The main polar lipids of strain DJCT were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was Q-10. The major fatty acid was C18 : 1ω7c. Genome sequencing revealed a genome size of 4.61 Mbp and a G+C content of 62.9 mol%. Analysis of 16S rRNA sequences showed that strain DJCT belonged to the genus Tabrizicola, with the closest neighbour Tabrizicola aquatica RCRI19T (97.5 %). DNA-DNA relatedness between strain DJCT and the closest phylogenetically related strain T. aquatica RCRI19T was 40.8 %. Stain DJCT was clearly distinguished from the type strain mentioned above through phylogenetic analysis, DNA-DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristic comparisons. Based on its phenotypic and chemotaxonomic characteristics, strain DJCT could be classified as a representative of a novel species of the genus for which the name Tabrizicola alkalilacus sp. nov. is proposed. The type strain is DJCT (=CICC 24242T=KCTC 62173T).

Flavobacterium tibetense sp. nov., isolated from a wetland.

A novel, Gram-stain-negative, non-motile and rod-shaped bacterium, designated YH5T, was isolated from the YonghuCo wetland on the Tibetan Plateau. The strain was able to grow optimally with 1 % (w/v) NaCl and tolerated up to 3 % NaCl. Growth occurred at pH 6-9 (optimum pH 7) and 10-37 °C (optimum 30 °C). Vitamins were not required for growth. The major polar lipid of strain YH5T was phosphatidylethanolamine. The predominant respiratory quinone was menaquinone 6 (MK-6). The major fatty acids were iso-C15 : 0, C16 : 0 10-methyl and/or iso-C17 : 1ω9c, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0 3-OH. Genome sequencing revealed a genome size of 2.74 Mbp and a G+C content of 33.3 mol%. Analysis of 16S rRNA gene sequences showed that strain YH5T belonged to the genus Flavobacterium, with the closest neighbours Flavobacterium luticocti xz20T (96.7 % similarity), Flavobacterium jejuense EC11T (96.4 %), Flavobacterium jumunjinense HME7102T (95.9 %) and Flavobacterium dongtanense LW30T (95.6 %). DNA-DNA relatedness between strain YH5T and the closest phylogenetically related strain F. luticocti xz20T was 27.0 %. Strain YH5T was clearly distinguished from the reference type strains based on phylogenetic analysis, DNA-DNA hybridization, fatty acid composition and a range of physiological and biochemical characteristics. Based on its phenotypic and chemotaxonomic characteristics, strain YH5T is classified as a representative of a novel species of the genus Flavobacterium, for which the name Flavobacterium tibetense sp. nov. is proposed. The type strain is YH5T (=CICC 24247T=KCTC 62174T).

Nitrincola tibetensis sp. nov., isolated from Lake XuguoCo on the Tibetan Plateau.

A novel Gram-stain-negative, motile and rod-shaped bacterium, designated xg18T, was isolated from Lake XuguoCo on the Tibetan Plateau. The strain was able to grow optimally at 0-2 % NaCl and tolerate up to 6 % NaCl. Growth occurred at pH 7.0-11.0 (optimum, pH 9.0-10.0) and 15-40 °C (optimum, 37 °C). Vitamins were not required for growth. The major polar lipids of strain xg18T were phosphatidyl ethanolamine and phosphatidylglycerol. The predominant respiratory quinone was Q-8. The major fatty acids were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The G+C content of genomic DNA was 46.1 mol%. Analysis of 16S rRNA sequences showed that strain xg18T belongs to the genus Nitrincola, with Nitrincola alkalisediminis MEB087T (KC822363, 98.6 %) as its closest neighbour. The DNA-DNA relatedness value of strain xg18T with its closest phylogenetic neighbour, N. alkalisediminis JCM 19317T, was 43.1±3.2 %. Strain xg18T was clearly distinguishable from the type strain of the genus Nitrincola through phylogenetic analysis, fatty acid composition data and a range of physiological and biochemical characteristics comparisons. Based on its phenotypic and chemotaxonomic characteristics, strain xg18T could be classified as a representative of a novel species of the genus for which the name Nitrincola tibetensis sp. nov. is proposed. The type strain is xg18T (=CICC 24457T=KCTC 62401T).

Roseovarius tibetensis sp. nov., a halophilic bacterium isolated from Lake LongmuCo on Tibetan Plateau.

Two Gram-stain negative halophilic strains, designated as LM2T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C18:1ω7c/C18:1ω6c, C16:0, C19:0 cyclo ω8c, and 11-methyl C18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2T and LM4, 24.9% relatedness between LM2T and R. tolerans EL-172T, and 36.3% relatedness between LM4 and R. tolerans EL-172T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2T (= CGMCC 1.16230T = KCTC 62028T).

Halomonas tibetensis sp. nov., isolated from saline lakes on Tibetan Plateau.

Strains pyc13T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEnT as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C18:1ω6c/C18:1ω7c, C16:1ω6c/C16:1ω7c, C16:0, and C12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEnT, H. sediminicola CPS11T, H. mongoliensis Z-7009T, H. ventosae Al12T, and H. fontilapidosi 5CRT, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13T (= CGMCC 1.15949T = KCTC 52660T).

Pelagibacterium montanilacus sp. nov., an alkaliphilic bacterium isolated from Lake Cuochuolong on the Tibetan Plateau.

A Gram-stain negative, alkaliphilic and halotolerant bacterium, designated CCL18T, was isolated from Lake Cuochuolong on the Tibetan Plateau. The strain was aerobic, short rod-shaped, catalase- and oxidase-positive, and motile by means of several polar flagella. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain CCL18T belongs to the genus Pelagibacterium, with its two closest neighbours being Pelagibacterium halotolerans B2T (96.6 %, 16S rRNA gene sequence similarity) and Pelagibacterium luteolum 1_C16_27T (96.1 %). The predominant respiratory quinone of strain CCL18T was Q-10, with Q-9 as a minor component. The major fatty acids were C18 : 1ω6c/C18 : 1ω7c (60.4 %), C19 : 0cyclo ω8c (8.1 %) and C18 : 0 (6.8 %). The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, seven kinds of unidentified lipids and three kinds of glycolipids. The DNA G+C content was 60.1 mol%. DNA-DNA hybridization showed 35.2 % relatedness between strain CCL18T and P. halotolerans B2T and 24.6 % relatedness to P. luteolum 1_C16_27T. Based on phylogenetic analysis, DNA-DNA hybridization and a range of physiological and biochemical characteristics, strain CCL18T was clearly distinguishable from the other strains of the genus Pelagibacterium. It was evident that strain CCL18T could be classified as a novel species of the genus Pelagibacterium, for which the name Pelagibacterium montanilacus sp. nov. is proposed. The type strain is CCL18T (=CGMCC 1.16231T=KCTC 62030T).