Haloterrigena Gelatinilytica sp. nov., A New Extremely Halophilic Archaeon Isolated From Salt-Lake

Two extremely halophilic strains, designated SYSU A558-1T and SYSU A121-1, were isolated from a saline sediment sample collected from Aiding salt lake, China. Cells of strains SYSU A558-1T and SYSU A121-1 were Gram-stain-negative, coccoid, and non-motile. The isolates were aerobic and grew at NaCl concentration of 10-30% (optimum, 20-22%), at 20-55ºC (optimum, 37-42ºC) and at pH 6.5-8.5 (optimum, 7.0-8.0). Cells lysed in distilled water. Major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, disulphated diglycosyl diether-1 and one unidentified glycolipid. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the two strains SYSU A558-1T and SYSU A121-1 were closely related to the membranes of the genus Haloterrigena. Phylogenetic trees based on strains SYSU A558-1T and SYSU A121-1 16S rRNA gene sequence, rpoB' gene sequence and concatenation of 87 protein markers demonstrated a robust clade with Haloterrigena turkmenica, Haloterrigena salifodinae and Haloterrigena salina. The genomic DNA G+C contents of strains SYSU A558-1T and SYSU A121-1 were 65.8 and 65.0%, respectively. Phenotypic, chemotaxonomic characteristics and phylogenetic properties suggested that the two strains SYSU A558-1T and SYSU A121-1 represent a novel species of the genus Haloterrigena, for which the name Haloterrigena gelatinilytica sp. nov. is proposed. The type strain is SYSU A558-1T (= KCTC 4259T = CGMCC 1.15953T).

Phylogeny of different Helicobacter pylori strains could not be explained by 16S rRNA gene due to high similarity in gene sequence across strains

Understanding the evolutionary relatedness of different strains of a species helped identify strain-specific differences that may be useful for disease diagnosis and treatment. Typically, such strain level typing would be augmented by molecular assays such as DNA sequencing, and phylogenetic tree analysis. This work utilizes public data on the 16S rRNA gene sequence of different strains of Helicobacter pylori to help plot the phylogenetic tree that describes the evolutionary trajectories of the different strains. Results from multiple sequence alignment reveals high level of conservation in 16S rRNA gene sequence across strains. This then translates into a phylogenetic tree structure that suggests very close evolutionary relationships of the different strains except for one outlier strain. Even in the case of the outlier strain, its evolutionary distance from other brethren was also not large. Overall, the results obtained in this study indicates that 16S rRNA gene may not capture strain-level phylogeny between different strains of the same species, and point to efforts in elucidating this phylogenetic effect in other genes of the species. Such genes may be involved in virulence during pathogenesis in humans, and may thus be subjected to higher evolutionary pressure and natural selection.

Streptomyces silvae sp. nov., isolated from forest soil

A bacterial strain, named For3T, was isolated from forest soil sampled in Champenoux, France. Based on its 16S rRNA gene sequence, the strain was affiliated to the family Streptomycetaceae and, more specifically, to the genus Streptomyces . The strain had 99.93% 16S rRNA gene sequence similarity to its closest relative strains Streptomyces pratensis ATCC 33331T, Streptomyces anulatus ATCC 27416T, Streptomyces setonii NRRL ISP-5322T and Kitasatospora papulosa NRRL B-16504T. The phylogenomic tree using the genome blast distance phylogeny method showed that the closest relative strain was Streptomyces atroolivaceus NRRL ISP-5137T and that For3T represents a new branch among the Streptomyces . Genome relatedness indexes revealed that the average nucleotide identity and digital DNA–DNA hybridization values between For3T and its closest phylogenomic relative ( S. atroolivaceus NRRL ISP-5137T) were 88.39 and 39.2 %, respectively. The G+C content of the genome was 71.4 mol% and its size was 7.96 Mb with 7492 protein-coding genes. Strain For3T harboured complete metabolic pathways absent in the closest relative strains such as cellulose biosynthesis, glycogen degradation I, glucosylglycerate biosynthesis I. Anteiso-C15:0, iso-C15:0, anteiso-C17:0 and MK-9(H4)/MK-9(H6) were the predominant cellular fatty acids and respiratory quinones, respectively. Phenotypic and genomic data supported the assignment of strain For3T to a novel species Streptomyces silvae sp. nov., within the genus Streptomyces , for which the type strain is For3T (=CIP 111908T=LMG 32186T).

Genome Mining Revealed Polyhydroxybutyrate Biosynthesis by Ramlibacter Agri Sp. Nov., Isolated from Agriculture Soil in Korea

A white-colony-forming, aerobic, motile and Gram-stain-negative bacterium, designated G-1-2-2T was isolated from soil of agriculture field near Kyonggi University, Republic of Korea. Strain G-1-2-2T synthesize the polyhydroxybutyrate and could grow at 10–35°C. The phylogenetic analysis of its 16S rRNA gene sequence, strain G-1-2-2T formed a lineage within the family Comamonadaceae and clustered as a member of the genus Ramlibacter. The 16S rRNA gene sequence of strain G-1-2-2T showed high sequence similarities with Ramlibacter ginsenosidimutans BXN5-27T (97.9%), Ramlibacter monticola G-3-2T (97.9%) and Ramlibacter alkalitolerans CJ661T (97.4%). The sole respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified phospholipid. The principal cellular fatty acids were C16:0, cyclo-C17:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 8 (C18:1ω7c and/or C18:1ω6c). The genome of strain G-1-2-2T was 7,200,642 bp long with 13 contigs, 6,647 protein-coding genes, and DNA G+C content of 68.9%. The average nucleotide identity and in silico DNA–DNA hybridization values between strain G-1-2-2T and closest members were ≤81.2 and 24.1%, respectively. The genome of strain G-1-2-2T showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome mining revealed the presence of atoB, atoB2, phaS, phbB, phbC, bhbD genes in the genome which are responsible for polyhydroxybutyrate biosynthesis. Based on these data, strain G-1-2-2T represents a novel species in the genus Ramlibacter, for which the name Ramlibacter agri sp. nov. is proposed. The type strain is G-1-2-2T (= KACC 21616T = NBRC 114389T).

Devosia litorisediminis sp. nov., isolated from a sand dune

A Gram-negative, aerobic, non-motile, and rod-shaped bacterial strain, designated BSSL-BM10T, was isolated from a sand dune that was collected from the Yellow Sea, Republic of Korea. It was subjected to a polyphasic taxonomic study. 16S rRNA gene sequence analysis showed that strain BSSL-BM10T fell phylogenetically within the radiation comprising type strains of Devosia species. The 16S rRNA gene sequence of strain BSSL-BM10T shared sequence similarities of 98.2% with the type strain of D. naphthalenivorans and 93.5-97.7% with type strains of other Devosia species. ANI and dDDH values between strain BSSL-BM10T and type strains of 18 Devosia species were 71.0-78.4% and 18.8-21.5%, respectively. The DNA G+C content of strain BSSL-BM10T was 60.9% based on its genomic sequence data. Strain BSSL-BM10T contained Q-10 as the predominant ubiquinone and 11-methyl C18:1 ω7c, C18:1 ω7c, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and C16:0 as its major fatty acids. Major polar lipids of strain BSSL-BM10T were phosphatidylglycerol and two unidentified glycolipids. Strain BSSL-BM10T showed distinguished phenotypic properties with its phylogenetic and genetic distinctiveness separated from recognized Devosia species. Based on data presented in this study, strain BSSL-BM10T should be placed in the genus Devosia. The name Devosia litorisediminis sp. nov. is proposed for strain BSSL-BM10T (= KACC 21633T = NBRC 115152T).

Establishment of a New Filamentous Cyanobacterial Genus, Microcoleusiopsis gen. nov. (Microcoleaceae, Cyanobacteria), from Benthic Mats in Open Channel, Jiangxi Province, China

Cyanobacterial taxonomic studies performed by using the modern approaches always lead to creation of many new genera and species. During the field survey for cyanobacterial resources in China, a filamentous cyanobacterial strain was successfully isolated from a microbial mat attached to rock surfaces of the Ganfu Channel, Jiangxi Province, China. This strain was morphologically similar to the cyanobacterial taxa belonging to the genera Microcoleus and Phormidium. The phylogenetic analyses based on 16S rRNA gene sequences showed that this strain formed a well-supported clade, close to the filamentous genera Microcoleus, Tychonema, and Kamptonema. The maximum similarity of 16S rRNA gene sequence of this strain with the related genera was 95.04%, less than the threshold for distinguishing bacterial genus. The ITS secondary structures also distinguish this strain from the related cyanobacterial genera. Therefore, combined with morphology, 16S rRNA gene sequence, and ITS secondary structures, a novel cyanobacterial genus here as Microcoleusiopsis was established, with the species type as Microcoleusiopsis ganfuensis.

Alkalihalobacterium elongatum gen. nov. sp. nov.: An Antibiotic-Producing Bacterium Isolated From Lonar Lake and Reclassification of the Genus Alkalihalobacillus Into Seven Novel Genera

A Gram-stain positive, long, rod-shaped, motile, and spore-forming bacterium (MEB199T) was isolated from a sediment sample collected from Lonar Lake, India. The strain was oxidase and catalase positive. The strain grew optimally at pH 10, NaCl concentration of 3.5% at 37°C. The major fatty acids were iso-C15:0, iso-C16:0, anteiso-C15:0, and iso-C17:0. The peptidoglycan contained meso-diaminopimelic acid (meso-DAP). Phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol were the major polar lipids of MEB199T. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain MEB199T belonged to the family Bacillaceae and exhibited a distinctive position among the members of the genus Alkalihalobacillus (Ahb.). Strain MEB199T shared the highest 16S rRNA gene sequence similarity with Alkalihalobacillus alkalinitrilicus ANL-iso4T (98.36%), whereas with type species Ahb. alcalophilus DSM 485T, it is 94.91%, indicating that strain MEB199T is distinctly related to the genus Alkalihalobacillus. The G + C content of genomic DNA was 36.47 mol%. The digital DNA–DNA hybridization (dDDH) (23.6%) and average nucleotide identity (ANI) (81%) values between strain MEB199T and Ahb. alkalinitrilicus ANL-iso4T confirmed the novelty of this new species. The pairwise identity based on the 16S rRNA gene sequence between the species of genus Alkalihalobacillus ranges from 87.4 to 99.81% indicating the heterogeneity in the genus. The different phylogenetic analysis based on the genome showed that the members of the genus Alkalihalobacillus separated into eight distinct clades. The intra-clade average amino acid identity (AAI) and percentage of conserved proteins (POCP) range from 52 to 68% and 37 to 59%, respectively, which are interspersed on the intra-genera cutoff values; therefore, we reassess the taxonomy of genus Alkalihalobacillus. The phenotypic analysis also corroborated the differentiation between these clades. Based on the phylogenetic analysis, genomic indices, and phenotypic traits, we propose the reclassification of the genus Alkalihalobacillus into seven new genera for which the names Alkalihalobacterium gen. nov., Halalkalibacterium gen. nov., Halalkalibacter gen. nov., Shouchella gen. nov., Pseudalkalibacillus gen. nov., Alkalicoccobacillus gen. nov., and Alkalihalophilus gen. nov. are proposed and provide an emended description of Alkalihalobacillus sensu stricto. Also, we propose the Ahb. okuhidensis as a heterotypic synonym of Alkalihalobacillus halodurans. Based on the polyphasic taxonomic analysis, strain MEB199T represents a novel species of newly proposed genus for which the name Alkalihalobacterium elongatum gen. nov. sp. nov. is proposed. The type strain is MEB199T (= MCC 2982T, = JCM 33704T, = NBRC 114256T, = CGMCC 1.17254T).

Pengzhenrongella sicca gen. nov., sp. nov., a new member of suborder Micrococcineae isolated from High Arctic tundra soil

A yellow bacterial strain, designated LRZ-2T, was isolated from High Arctic tundra near the settlement Ny-Ålesund in the Svalbard Archipelago, Norway. The cells were Gram-stain-positive, aerobic and non-sporulating. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain LRZ-2T represented a novel member of the suborder Micrococcineae . Its nearest phylogenetic neighbours were the members of the genus Luteimicrobium , with 16S rRNA gene sequence similarity of 95.3–96.9 %. The average nucleotide identity and digital DNA–DNA hybridization values between the genomes of strain LRZ-2T and its closely related strains were 77.4–74.3 % and 21.4–19.6 %, respectively. The DNA G+C content was 72.4 mol%. The peptidoglycan type of the isolate was A4β with an interpeptide bridge comprising l-ornithine and d-glutamic acid. The predominant menaquinone was MK-9 (H4) and the major fatty acids were anteiso-C15 : 0, C16 : 0, anteiso-C15 : 1 A, anteiso-C17 : 0 and iso-C15 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, phosphatidylinositol dimannoside, unidentified phosphoglycolipid, four unidentified phospholipids and two unidentified polar lipids. Strain LRZ-2T showed a 16S rRNA gene signature pattern consisting of nucleotides at positions 120 (A), 131–231 (C-G), 196 (C), 342–347 (C-G), 444–490 (A-U), 580–761 (C-G), 602–636 (C-G), 670–736 (A-U), 822–878 (G-C), 823–877 (G-C), 826–874 (C-G), 827 (U), 843 (C), 950–1231 (U-A), 1047–1210 (G-C), 1109 (C), 1145 (G), 1309–1328 (G-C), 1361 (G) and 1383 (C), which clearly distinguished it from all genera previously reported in the suborder Micrococcineae . On the basis of the phylogenetic, phenotypic and chemotaxonomic data, strain LRZ-2T is considered to represent a novel species of a new genus, for which the name Pengzhenrongella sicca gen. nov., sp. nov. is proposed. The type strain of Pengzhenrongella sicca is LRZ-2T (=CCTCC AB 2012163T=DSM 100332T).