Characterization of Microaerobacter geothermalis gen. nov., sp. nov., a novel microaerophilic, nitrate- and nitrite-reducing thermophilic bacterium isolated from a terrestrial hot spring in Tunisia

A novel thermophilic anaerobic and microaerophilic bacterium (optimal growth in the presence of 5–10% O₂), strain Nad S1^T was isolated from the terrestrial hot spring of Hammam Sidi Jdidi, Nabeul, Tunisia. Cells were motile rods having a Gram-positive cell wall structure. Strain Nad S1^T grew optimally at 55°C (range 37–70°C). Optimum pH for growth was 6.5–7.0. It was halotolerant growing with NaCl up to 7% (optimum concentration 1.5–3.0%). It grew chemoorganotrophically on various carbohydrates, organic-acids and amino-acids as energy sources, or chemolithotrophically on H₂ using nitrate, as terminal electron acceptor. Beside oxygen (under microaerobic conditions) and nitrate, nitrite was also used. Nitrate was completely reduced to N₂. No fermentation occurred. The genomic DNA G + C content was 41.8 mol%. Based on 16S rRNA gene sequence analysis, strain Nad S1^T belongs to the Bacillaceae family within the class ‘Bacilli’. Because of its phylogenetic and phenotypic characteristics, we propose this isolate to be assigned as a novel genus and a novel species within the domain Bacteria, Microaerobacter geothermalis gen. nov., sp. nov. The type strain is Nad S1^T (=DSM 22679^T =JCM 16213^T).     

Thermovorax subterraneus, gen. nov., sp. nov., a thermophilic hydrogen-producing bacterium isolated from geothermally active underground mine

A thermophilic, rod-shaped, motile, Gram-positive, spore-forming bacterium strain 70B^T was isolated from a geothermally active underground mine in Japan. The temperature and pH range for growth was 50–81°C (optimum 71°C) and 6.2–9.8 (optimum pH 7–7.5), respectively. Growth occurred in the presence 0–2% NaCl (optimum 1% NaCl). Strain 70B^T could utilize glucose, fructose, mannose, mannitol, pyruvate, cellobiose and tryptone as substrates. Thiosulfate was used as electron acceptor. Major whole-cell fatty acids were iso-C_15:0, C_16:0 DMA (dimethyl acetal), C_16:0 and anteiso-C_15:0. The G+C mol% of the DNA was 44.2%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the closest relatives of strain 70B^T were Thermosediminibacter oceani DSM 16646^T (94% similarity) and Thermosediminibacter litoriperuensis DSM 16647 (93% similarity). The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain 70B^T represents a novel species in a new genus, for which the name Thermovorax subterraneus gen. nov., sp. nov. is proposed. The type strain of Thermovorax subterraneus is 70B^T (=DSM 21563 = JCM 15541).     

<Emphasis Type="Italic">Desulfovibrio legallis</Emphasis> sp. nov.: A Moderately Halophilic,Sulfate-Reducing Bacterium Isolated from a Wastewater Digestor in Tunisia

A new moderately halophilic sulfate-reducing bacterium (strain H₁^T) was enriched and isolated from a wastewater digestor in Tunisia. Cells were curved, motile rods (2–3 x 0.5 μm). Strain H₁^T grew at temperatures between 22 and 43°C (optimum 35°C), and at pH between 5.0 and 9.2 (optimum 7.3–7.5). Strain H₁^T required salt for growth (1–45 g of NaCl/l), with an optimum at 20–30 g/l. Sulfate, sulfite, thiosulfate, and elemental sulfur were used as terminal electron acceptors but not nitrate and nitrite. Strain H₁^T utilized lactate, pyruvate, succinate, fumarate, ethanol, and hydrogen (in the presence of acetate and CO₂) as electron donors in the presence of sulfate as electron acceptor. The main end-products from lactate oxidation were acetate with H₂ and CO₂. The G + C content of the genomic DNA was 55%. The predominant fatty acids of strain H₁^T were C_15:0 iso (38.8%), C_16:0 (19%), and C_14:0 iso 3OH (12.2%), and menaquinone MK-6 was the major respiratory quinone. Phylogenetic analysis of the small-subunit (SSU) ribosomal RNA (rRNA) gene sequence indicated that strain H₁^T was affiliated to the genus Desulfovibrio. On the basis of SSU rRNA gene sequence comparisons and physiological characteristics, strain H₁^T is proposed to be assigned to a novel species of sulfate reducers of the genus Desulfovibrio, Desulfovibrio legallis sp. nov. (= DSM 19129^T = CCUG 54389^T).     

Characterization of Halanaerobaculum tunisiense gen. nov., sp. nov., a new halophilic fermentative, strictly anaerobic bacterium isolated from a hypersaline lake in Tunisia

A new halophilic anaerobe was isolated from the hypersaline surface sediments of El-Djerid Chott, Tunisia. The isolate, designated as strain 6SANG, grew at NaCl concentrations ranging from 14 to 30%, with an optimum at 20–22%. Strain 6SANG was a non-spore-forming, non-motile, rod-shaped bacterium, appearing singly, in pairs, or occasionally as long chains (0.7–1 × 4–13 μm) and showed a Gram-negative-like cell wall pattern. It grew optimally at pH values between 7.2 and 7.4, but had a very broad pH range for growth (5.9–8.4). Optimum temperature for growth was 42°C (range 30–50°C). Strain 6SANG required yeast extract for growth on sugars. Glucose, sucrose, galactose, mannose, maltose, cellobiose, pyruvate, and starch were fermented. The end products from glucose fermentation were acetate, butyrate, lactate, H₂, and CO₂. The G + C ratio of the DNA was 34.3 mol%. Strain 6SANG exhibited 16S rRNA gene sequence similarity values of 91–92% with members of the genus Halobacteroides, H. halobius being its closest phylogenetic relative. Based on phenotypic and phylogenetic characteristics, we propose that this bacterium be classified as a novel species of a novel genus, Halanaerobaculum tunisiense gen. nov., sp. nov. The type strain is 6SANG^T (=DSM 19997^T = JCM 15060^T).     

Desulfosoma profundi sp. nov., a thermophilic sulfate-reducing bacterium isolated from a deep terrestrial geothermal spring in France

A novel strictly anaerobic bacterium designated SPDX02-08^T was isolated from a deep terrestrial geothermal spring located in southwest France. Cells (1–2 × 2–6 μm) were non-motile, non sporulating and stained Gram negative. Strain SPDX02-08^T grew at a temperature between 40 and 60°C (optimum 55°C), pH between 6.3 and 7.3 (optimum 7.2) and a NaCl concentration between 0 and 5 g/l (optimum 2 g/l). Sulfate, thiosulfate and sulfite were used as terminal electron acceptors, but not elemental sulfur, nitrate, nitrite, Fe (III) or fumarate. In the presence of sulfate, strain SPDX02-08^T completely oxidized pyruvate, propionate, butyrate, isobutyrate, valerate, isovalerate and hexadecanoate. Stoichiometric measurements revealed a complete oxidation of part of lactate (0.125 mol of acetate produced per mole lactate oxidized). Strain SPDX02-08^T required yeast extract to oxidize formate and H₂ but did not grow autotrophically on H₂. Among the substrates tested, only pyruvate was fermented. The G+C content of the genomic DNA was 57.6 mol%. Major cellular fatty acids of strain SPDX02-08^T were iso-C_15:0, C_15:0, and C_16:0. Phylogenetic analysis of the 16S small-subunit (SSU) ribosomal RNA gene sequence indicated that strain SPDX02-08^T belongs to the genus Desulfosoma, family Syntrophobacteraceae, having Desulfosoma caldarium as its closest phylogenetic relative (97.6% similarity). The mean DNA/DNA reassociation value between strain SPDX02-08^T and Desulfosoma caldarium was 16.9 ± 2.7%. Based on the polyphasic differences, strain SPDX02-08^T is proposed to be assigned as a new species of the genus Desulfosoma, Desulfosoma profundi sp. nov. (DSM 22937^T = JCM 16410^T). GenBank accession number for the 16S rRNA gene sequence of strain SPDX02-08^T is HM056226.     

Description of the novel perchlorate-reducing bacteria Dechlorobacter hydrogenophilus gen. nov., sp. nov. and Propionivibrio militaris, sp. nov.

Novel dissimilatory perchlorate-reducing bacteria (DPRB) were isolated from enrichments conducted under conditions different from those of all previously described DPRB. Strain LT-1^T was enriched using medium buffered at pH 6.6 with 2-(N-morpholino)ethanesulfonic acid (MES) and had only 95% 16S rRNA gene identity with its closest relative, Azonexus caeni. Strain MP^T was enriched in the cathodic chamber of a perchlorate-reducing bioelectrical reactor (BER) and together with an additional strain, CR (99% 16S rRNA gene identity), had 97% 16S rRNA gene identity with Propionivibrio limicola. The use of perchlorate and other electron acceptors distinguished strains MP^T and CR from P. limicola physiologically. Strain LT-1^T had differences in electron donor utilization and optimum growth temperatures from A. caeni. Strains LT-1^T and MP^T are the first DPRB to be described in the Betaproteobacteria outside of the Dechloromonas and Azospira genera. On the basis of phylogenetic and physiological features, strain LT-1^T represents a novel genus in the Rhodocyclaceae; strain MP^T represents a novel species within the genus Propionivibrio. The names Dechlorobacter hydrogenophilus gen. nov., sp. nov and Propionivibrio militaris sp. nov. are proposed.     

Winogradskyella multivorans sp. nov., a polysaccharide-degrading bacterium isolated from seawater of an oyster farm

A novel bacterial strain, designated T-Y1^T, capable of degrading a variety of polysaccharides was isolated from seawater of an oyster farm in the South Sea, Korea. It was found to be aerobic, Gram-negative, non-flagellated, non-gliding and rod-shaped. Strain T-Y1^T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain T-Y1^T belonged to the genus Winogradskyella. Strain T-Y1^T exhibited 16S rRNA gene sequence similarity values of 95.0–96.8 % to the type strains of recognized Winogradskyella species and less than 94.5 % to other validly named species. The chemotaxonomic data concurred with the phylogenetic inference. Strain T-Y1^T contained MK-6 as the predominant menaquinone and anteiso-C_15:0, iso-C_15:0, iso-C_15:1 G and iso-C_16:0 3-OH as the major fatty acids. The major polar lipids of strain T-Y1^T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content was 36.2 mol%. Differential phenotypic properties, together with its phylogenetic distinctiveness, enabled strain T-Y1^T to be differentiated from the recognized Winogradskyella species. On the basis of the data presented here, strain T-Y1^T is considered to represent a novel species of the genus Winogradskyella, for which the name Winogradskyella multivorans sp. nov. is proposed. The type strain is T-Y1^T (=KCTC 23891^T = CCUG 62216^T).     

Description of Fimbriimonas ginsengisoli gen. nov., sp. nov. within the Fimbriimonadia class nov., of the phylum Armatimonadetes

Strain Gsoil 348^T was isolated from a ginseng field soil sample by selecting micro-colonies from one-fifth strength modified R2A agar medium after a long incubation period. 16S rRNA gene sequence analysis indicated that the strain is related to members of the phylum Armatimonadetes (formerly called candidate phylum OP10). Strain Gsoil 348^T is mesophilic, strictly aerobic, non-motile and rod-shaped. It only grows in low nutrient media. The major respiratory quinones are menaquinones MK-11 and MK-10, and the main fatty acids are iso-C_15:0, iso-C_17:0, C_16:0 and C_16:1 ω11c. The G+C content is 61.4 mol%. The 16S rRNA gene sequences in public databases belonging to the phylum Armatimonadetes were clustered here into 6 groups. Five of these groups constituted a coherent cluster distinct from the sequences of other phyla in phylogenetic trees that were constructed using multiple-outgroup sequences from 49 different phyla. On the basis of polyphasic taxonomic analyses, it is proposed that strain Gsoil 348^T (= KACC 14959^T = JCM 17079^T) should be placed in Fimbriimonas ginsengisoli gen. nov., sp. nov., as the cultured representative of the Fimbriimonadia class. nov., corresponding with Group 4 of the phylum Armatimonadetes.     

Desulfosporosinus acidiphilus sp. nov.: a moderately acidophilic sulfate-reducing bacterium isolated from acid mining drainage sediments

An obligately anaerobic, spore-forming, acidophilic sulfate-reducing bacterium, strain SJ4^T, was isolated from an acid mining effluent decantation pond sediment sample (pH around 3.0). Cells were Gram negative, non-motile, curved rods occurring singly. Strain SJ4^T grew at pH 3.6–5.5 with an optimum at pH 5.2. Strain SJ4^T utilized H₂, lactate, pyruvate, glycerol, glucose, and fructose as electron donors. Lactate and glucose were weakly used. Sulfate was used as electron acceptors, but not sulfite, elemental sulfur, arsenate (V), and fumarate. The G + C content of genomic DNA was 42.3 mol% (HPLC). 16S rRNA gene sequence analysis indicated that strain SJ4^T belonged to the genus Desulfosporosinus within the family Peptococcaceae in the phylum Firmicutes. The level of 16S rRNA gene sequence similarity with other Desulfosporosinus species was 94.7–96.2%, D. orientis DSM 765^T (similarity of 96.2%) and D. auripigmenti DSM 13351^T (similarity of 95%) being its closest relatives. DNA–DNA relatedness values with D. orientis and D. auripigmenti were 16.5 and 31.8%, respectively. On the basis of phenotypic, phylogenetic, and genetic characteristics, strain SJ4^T represents a novel species within the genus Desulfosporosinus, for which the name Desulfosporosinus acidiphilus sp. nov. is proposed. The type strain is SJ4^T (=DSM 22704^T = JCM 16185^T).     

Haloalkaliphilic spore-forming sulfidogens from soda lake sediments and description of Desulfitispora alkaliphila gen. nov., sp. nov.

An anaerobic enrichment with pyruvate as electron donor and thiosulfate at pH 10 and 0.6 M Na⁺ inoculated with pasteurized soda lake sediments resulted in a sulfidogenic coculture of two morphotypes of obligately anaerobic haloalkaliphilic endospore-forming clostridia, which were further isolated in pure culture. Strain AHT16 was a thin long rod able to ferment sugars and pyruvate and to respire H₂, formate and pyruvate using thiosulfate and fumarate as electron acceptors and growing optimally at pH 9.5. Thiosulfate was reduced incompletely to sulfide and sulfite. The strain was closely related (99% sequence similarity) to a peptolytic alkaliphilic clostridium Natronincola peptidovorans. Strain AHT17 was a short rod with a restricted respiratory metabolism, growing with pyruvate and lactate as electron donor and sulfite, thiosulfate and elemental sulfur as electron acceptors with a pH optimum 9.5. Thiosulfate was reduced completely via sulfite to sulfide. The ability of AHT17 to use sulfite explained the stability of the original coculture of the two clostridia—one member forming sulfite from thiosulfate and another consuming it. Strain AHT17 formed an independent deep phylogenetic lineage within the Clostridiales and is proposed as a new genus and species Desulfitisporum alkaliphilum gen. nov., sp. nov. (=DSM 22410^T = UNIQEM U794^T).     

Oceanibacterium hippocampi gen. nov., sp. nov., isolated from cutaneous mucus of wild seahorses (Hippocampus guttulatus)

A Gram-negative, aerobic, motile and slightly curved rod-shaped bacterium (BFLP-8^T) was isolated from cutaneous mucus of wild long-snouted seahorses (Hippocampus guttulatus) captured in northwest Spain (Toralla, Galicia). Strain BFLP-8^T grew at 10–35 °C and pH 5–9 (optimally at 25 °C and pH 7.0) and with 1–6 % (w/v) NaCl (optimally with 2 % NaCl). The predominant respiratory quinone (90 %) was ubiquinone with ten isoprene units (Q-10) and the major fatty acids identified were C_18:1 ω7c (54.8 % of the total), C_19:0 cyclo ω8c (11.6 %), C_16:0 (9.5 %), C_18:1 2-OH (7.1 %) and C_16:1 ω11c (6.7 %). The G+C content of the DNA was 57.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BFLP-8^T formed a distinct clade within the family Sneathiellaceae but is not specifically associated with any species in the family. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain BFLP-8^T represents a novel species within a new genus, for which the name Oceanibacterium hippocampi gen. nov., sp. nov. is proposed. The type strain is BFLP-8^T (=CECT 7691^T = DSM 23444^T).     

Cohnella boryungensis sp. nov., isolated from soil

A Gram-staining positive, endospore-forming, motile and rod-shaped bacterial strain, BR-29^T, was isolated from soil from west coast of the Korean peninsula, and its taxonomic position was investigated by a polyphasic study. Strain BR-29^T grew optimally at around pH 7.5, at 30°C and in the presence of 0.5% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BR-29^T fell into a clade comprising the type strains of Cohnella species, with which it exhibited 16S rRNA gene sequence similarity values of 92.8–96.4%. Strain BR-29^T contained a cell wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the predominant menaquinone. The major fatty acids were anteiso-C_15:0, C_16:0 and iso-C_16:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, lysylphosphatidylglycerol and two unidentified phospholipids; a minor amount of phosphatidylglycerol was present. The DNA G+C content was 54.9 mol%. Strain BR-29^T could be differentiated from phylogenetically related Cohnella species by differences in phenotypic characteristics. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain BR-29^T represents a novel species of the genus Cohnella, for which the name Cohnella boryungensis sp. nov., is proposed. The type strain is BR-29^T (= KCTC 13735^T = CCUG 59598^T).     

A genomic overview including polyphasic taxonomy of Thalassoroseus pseudoceratinae gen. nov., sp. nov. isolated from a marine sponge,Pseudoceratina sp.

A pink-coloured, salt- and alkali-tolerant planctomycetal strain (JC658^T) with oval to pear-shaped, motile, aerobic, Gram-negative stained cells was isolated from a marine sponge, Pseudoceratina sp. Strain JC658^T shares the highest 16S rRNA gene sequence identity with Maioricimonas rarisocia Mal4^T (<?89.2%) in the family Planctomycetaceae. The genomic analysis of the new strain indicates its biotechnological potential for the production of various industrially important enzymes, notably sulfatases and carbohydrate-active enzymes (CAZymes), and also potential antimicrobial compounds. Several genes encoding restriction-modification (RM) and CRISPR-CAS systems are also present. NaCl is obligate for growth, of which strain JC658^T can tolerate a concentration up to 6% (w/v). Optimum pH and temperature for growth are 8.0 (range 7.0–9.0) and 25 ºC (range 10–40 °C), respectively. The major respiratory quinone of strain JC658^T is MK6. Major fatty acids are C_16:1ω7c/C_16:1ω6c, C_18:0 and C_16:0. Major polar lipids are phosphatidylcholine, phosphatidyl-dimethylethanolamine and phosphatidyl-monomethylethanolamine. The genomic size of strain JC658^T is 7.36 Mb with a DNA G?+?C?content of 54.6 mol%. Based on phylogenetic, genomic (ANI, AAI, POCP, dDDH), chemotaxonomic, physiological and biochemical characteristics, we conclude that strain JC658^T belongs to a novel genus and constitutes a novel species within the family Planctomycetaceae, for which we propose the name Thalassoroseus pseudoceratinae gen. nov., sp. nov. The novel species is represented by the type strain JC658^T (=?KCTC 72881 ^T?=?NBRC 114371 ^T).

     

Microcella flavibacter sp. nov., isolated from marine sediment,and reclassification of Chryseoglobus frigidaquae,Chryseoglobus indicus,and Yonghaparkia alkaliphila as Microcella frigidaquae comb. nov., Microcella indica nom. nov., and Microcella alkalica nom. nov.

A novel Gram-staining positive, aerobic, rod-shaped, non-motile and yellow-pigmented actinobacterium, designated strain WY83^T, was isolated from a marine sediment of Indian Ocean. Strain WY83^T grew optimally at 30–35 °C, pH 7–8 and with 0–3% (w/v) NaCl. The predominant menaquinones were MK-10, MK-11 and MK-12, and the major fatty acids were C_19:1 ω9c/C19:1 ω11c, anteiso-C_15:0, C_17:0 3OH, and iso-C_16:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid. The cell-wall peptidoglycan contained lysine as a diamino acid. The DNA G?+?C content was 72.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences and ninety-two bacterial core genes indicated that strain WY83^T formed an evolutionary lineage with Chryseoglobus frigidaquae JCM 14730^T, Chryseoglobus indicus CTD02-10-2^T, Yonghaparkia alkaliphila JCM 15138^T, Microcella alkaliphila DSM 18851^T and Microcella putealis DSM 19627^T within the radiation enclosing members of the family Microbacteriaceae. All pairwise percentage of conserved proteins between strain WY83^T and the closely related phylogenetic neighbors were greater than 65%. The average nucleotide identity and in silico DNA–DNA hybridization values were both below the thresholds used for the delineation of a new species. On the basis of the evidence presented, strains WY83^T, Y. alkaliphila JCM 15138^T, C. frigidaquae JCM 14730^T, M. alkaliphila DSM 18851^T and M. putealis DSM 19627^T should belong to different species of the same genus. Strain WY83^T represents a novel species of the genus Microcella, for which the name Microcella flavibacter sp. nov. is proposed. The type strain is WY83^T (=?KCTC 39637^T?=?MCCC 1A07099^T). Furthermore, Chryseoglobus frigidaquae, Chryseoglobus indicus, and Yonghaparkia alkaliphila were reclassified as Microcella frigidaquae comb. nov., Microcella indica nom. nov., and Microcella alkalica nom. nov., respectively.

     

Alkalilactibacillus ikkensis, gen. nov., sp. nov., a novel enzyme-producing bacterium from a cold and alkaline environment in Greenland

Three novel Gram-positive, endospore-forming bacteria were isolated from a cold and alkaline environment. Phylogenetic analysis showed that the strains were almost identical, and that they were related to Natronobacillus azotifigens 24KS-1^T (95.8% identity), Paraliobacillus quinghaiensis YIM-C158^T (95.1%), Paraliobacillus ryukyuensis O15-7^T (94.5%), and Halolactibacillus miurensis M23-1^T (93.9%). The isolates produced amylase, α-galactosidase, β-galactosidase, and β-glucuronidase, and showed optimal growth at pH 10, at 20°C, and at 2–8% (w/v) NaCl. Major fatty acids were C_14:0 (10.6–11.6%), anteiso-C_15:0 (25.7–32.7%), C_16:1 ω11c (12.2–16.0%), and C_16:0 (14.0–20.4%). The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol, and meso-diaminopimelic acid was found in the cell-wall peptidoglycan. The G+C content was 38.4%. DNA–DNA hybridization between strain GCM68^T and H. miurensis M23-1^T was 32.4%, while hybridization to N. azotifigens 24KS-1^T, Amphibacillus tropicus Z-7792^T, and Paraliobacillus ryukyuensis O15-7^T was below 30%. The phylogenetic analysis and G+C content place strain GCM68^T in relation to species belonging to Bacillus rRNA group 1, but phylogenetic and physiologic data combined with chemotaxonomic analyses support our proposal for a new genus, Alkalilactibacillus, gen. nov., with the novel species Alkalilactibacillus ikkensis, sp. nov. (type strain is GCM68^T = DSM 19937 = LMG 24405).     

Aliidiomarina haloalkalitolerans sp. nov., a marine bacterium isolated from coastal surface seawater

A novel Gram-negative, rod shaped, motile, non-sporing strictly aerobic bacterium, designated strain AK5^T, was isolated from a sea water sample collected near Visakhapatnam coast, Bay of Bengal, India. Colonies on marine agar were circular, 3–4 mm in diameter, creamish and rose with entire margin. Growth occurred at 10–40°C, 0.5–12% (w/v) NaCl and pH of 7–11. Strain AK5^T was oxidase and catalase positive. The fatty acids were dominated by iso-branched saturated and unsaturated fatty acids with a high abundance of iso-C_15:0, iso-C_17:0 and summed feature 9 (as defined by MIDI). Q8 was found to be the major respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and four unidentified phospholipids as polar lipids. The DNA G+C content of strain AK5^T was 54.7 ± 0.2 mol%. Phylogenetic analysis revealed that strain AK5^T was a member of the genus Aliidiomarina and closely related to Aliidiomarina taiwanensis with a phylogenetic distance of 5.3% (94.7% 16S rRNA gene sequence similarity) and clustered with the same species. Results from the polyphasic taxonomy study support the conclusion that strain AK5^T represents a novel Aliidiomarina species, for which the name Aliidiomarina haloalkalitolerans sp. nov. is proposed. The type strain of A. haloalkalitolerans is AK5^T (= MTCC 11064^T = JCM 17359^T).     

Zhihengliuella salsuginis sp. nov., a moderately halophilic actinobacterium from a subterranean brine

A novel moderately halophilic, alkaliphilic, non-motile, non-sporulating, catalase-positive, oxidase-negative, aerobic, coccus-shaped, Gram-positive bacterium, designated strain JSM 071043^T, was isolated from a subterranean brine sample collected from a salt mine in Hunan Province, China. Growth occurred with 0.5–20% (w/v) NaCl (optimum 5–10%) at pH 6.5–10.5 (optimum pH 8.5) and at 10–40°C (optimum 25–30°C). Good growth also occurred in the presence of 0.5–20% (w/v) KCl (optimum 5–8%) or 0.5–25% (w/v) MgCl₂·6H₂O (optimum 5–10%). The peptidoglycan type was A4α (l-Lys–l-Ala–l-Glu) and major cell-wall sugars were tyvelose and mannose. The major cellular fatty acids were anteiso-C_15:0, iso-C_16:0 and anteiso-C_17:0. Strain JSM 071043^T contained MK-9 and MK-8 as the predominant menaquinones and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the major polar lipids. The DNA G + C content was 67.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JSM 071043^T was a member of the suborder Micrococcineae, and was most closely related to Zhihengliuella halotolerans YIM 70185^T (sequence similarity 98.9%) and Zhihengliuella alba YIM 90734^T (98.2%), and the three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis, DNA–DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 071043^T represents a novel species of the genus Zhihengliuella, for which the name Z. salsuginis sp. nov. is proposed. The type strain is JSM 071043^T (= DSM 21149^T = KCTC 19466^T).     

Salinimonas lutimaris sp. nov., a polysaccharide-degrading bacterium isolated from a tidal flat

A Gram-negative, non-motile, non-endospore-forming bacterial strain, designated DPSR-4^T, was isolated from a tidal flat sediment on the southern coast of Korea. Strain DPSR-4^T grew optimally at 25–30°C, at pH 7.0–7.5 and in the presence of 2% (w/v) NaCl. A Neighbour-Joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DPSR-4^T clustered with Salinimonas chungwhensis BH030046^T by a high bootstrap resampling value of 99.7%. Strain DPSR-4^T exhibited 96.2% 16S rRNA gene sequence similarity to that of S. chungwhensis BH030046^T and 93.7–96.6% sequence similarity to the sequences of type strains of Alteromonas species. Strain DPSR-4^T contained Q-8 as the predominant ubiquinone and iso-C_15:0 2-OH and/or C_16:1 ω7c, C_16:0 and C_18:1 ω7c as the major fatty acids. The major polar lipids detected in strain DPSR-4^T and S. chungwhensis KCTC 12239^T were phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The DNA G+C content was 53.4 mol%. Differential phenotypic properties and phylogenetic distinctiveness of strain DPSR-4^T demonstrated that this strain is distinguishable from the sole recognized species of the genus Salinimonas, S. chungwhensis. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain DPSR-4^T is considered to represent a novel species of the genus Salinimonas, for which the name Salinimonas lutimaris sp. nov. is proposed. The type strain is DPSR-4^T (KCTC 23464^T, CCUG 60743^T).     

Nocardioides panzhihuaensis sp. nov., a novel endophytic actinomycete isolated from medicinal plant Jatropha curcas L.

A novel Gram-positive, aerobic, rod-shaped and mycelia-producing bacterial strain, designated KLBMP 1050^T, was isolated from the stem of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate KLBMP 1050^T belonged to the genus Nocardioides, with the highest sequence similarity to Nocardioides albus KCTC 9186^T (99.38 %) and Nocardioides luteus KCTC 9575^T (99.03 %). However, the DNA–DNA relatedness of isolate KLBMP 1050^T to these two type strains were 37.5 ± 3.5 and 33 ± 2.3 %, respectively. Strain KLBMP 1050^T grew at the pH range 6–11, temperature range 10–32 °C and with 0–12 % NaCl. The physiological properties of strain KLBMP 1050^T differ from those of N. albus KCTC 9186^T and N. luteus KCTC 9575^T. The cell-wall peptidoglycan contained ll-diaminopimelic acid and MK-8(H₄) was the major respiratory quinone. The predominant cellular fatty acid of strain KLBMP 1050^T was iso-C_16:0 (23.3 %). The total DNA G+C content was 70.1 mol%. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain KLBMP 1050^T represents a novel species of the genus Nocardioides, for which the name Nocardioides panzhihuaensis sp. nov. is proposed. The type strain is KLBMP 1050^T (= KCTC 19888^T = NBRC 108680^T).     

Fontisphaera persica gen. nov., sp. nov., a thermophilic hydrolytic bacterium from a hot spring of Baikal lake region,and proposal of Fontisphaeraceae fam. nov., and Limisphaeraceae fam. nov. within the Limisphaerales ord. nov. (Verrucomicrobiota)

A novel facultatively anaerobic moderately thermophilic bacterium, strain B-154 ^T, was isolated from a terrestrial hot spring in the Baikal lake region (Russian Federation). Gram-negative, motile, spherical cells were present singly, in pairs, or aggregates, and reproduced by binary fission. The strain grew at 30–57 °C and within a pH range of 5.1–8.4 with the optimum at 50 °C and pH 6.8–7.1. Strain B-154 ^T was a chemoorganoheterotroph, growing on mono-, di- and polysaccharides (xylan, starch, galactan, galactomannan, glucomannan, xyloglucan, pullulan, arabinan, lichenan, beta-glucan, pachyman, locust bean gum, xanthan gum). It did not require sodium chloride or yeast extract for growth. Major cellular fatty acids were anteiso-C_15:0, iso-C_16:0 and iso-C_14:0. The respiratory quinone was MK-7. The complete genome of strain B-154 ^T was 4.73 Mbp in size; its G + C content was 61%. According to the phylogenomic analysis strain B-154 ^T forms a separate family-level phylogenetic lineage. Moreover, together with Limisphaera ngatamarikiensis and “Pedosphaera parvula” this strain forms a separate order-level phylogenetic lineage within Verrucomicrobiae class. Hence, we propose a novel order, Limisphaerales ord. nov., with two families Limisphaeraceae fam. nov. and Fontisphaeraceae fam. nov., and a novel genus and species Fontisphaera persica gen. nov., sp. nov. with type strain B-154 ^T. Ecogenomic analysis showed that representatives of the Limisphaerales are widespread in various environments. Although some of them were detected in hot springs the majority of Limisphaerales (54% of the studied metagenome-assembled genomes) were found in marine habitats. This study allowed a better understanding of physiology and ecology of Verrucomicrobiota – a rather understudied bacterial phylum.