Genomic analysis provides novel insights into diversification and taxonomy of Allorhizobium vitis (i.e. Agrobacterium vitis).

BACKGROUND: Allorhizobium vitis (formerly named Agrobacterium vitis or Agrobacterium biovar 3) is the primary causative agent of crown gall disease of grapevine worldwide. We obtained and analyzed whole-genome sequences of diverse All. vitis strains to get insights into their diversification and taxonomy. RESULTS: Pairwise genome comparisons and phylogenomic analysis of various All. vitis strains clearly indicated that All. vitis is not a single species, but represents a species complex composed of several genomic species. Thus, we emended the description of All. vitis, which now refers to a restricted group of strains within the All. vitis species complex (i.e. All. vitis sensu stricto) and proposed a description of a novel species, All. ampelinum sp. nov. The type strain of All. vitis sensu stricto remains the current type strain of All. vitis, K309T. The type strain of All. ampelinum sp. nov. is S4T. We also identified sets of gene clusters specific to the All. vitis species complex, All. vitis sensu stricto and All. ampelinum, respectively, for which we predicted the biological function and infer the role in ecological diversification of these clades, including some we could experimentally validate. All. vitis species complex-specific genes confer tolerance to different stresses, including exposure to aromatic compounds. Similarly, All. vitis sensu stricto-specific genes confer the ability to degrade 4-hydroxyphenylacetate and a putative compound related to gentisic acid. All. ampelinum-specific genes have putative functions related to polyamine metabolism and nickel assimilation. Congruently with the genome-based classification, All. vitis sensu stricto and All. ampelinum were clearly delineated by MALDI-TOF MS analysis. Moreover, our genome-based analysis indicated that Allorhizobium is clearly separated from other genera of the family Rhizobiaceae. CONCLUSIONS: Comparative genomics and phylogenomic analysis provided novel insights into the diversification and taxonomy of Allorhizobium vitis species complex, supporting our redefinition of All. vitis sensu stricto and description of All. ampelinum. Our pan-genome analyses suggest that these species have differentiated ecologies, each relying on specialized nutrient consumption or toxic compound degradation to adapt to their respective niche.

Rodentibacter haemolyticus sp. nov. isolated from laboratory rodents.

Nine strains of a Rodentibacter-related bacterium were isolated over a period of 38 years from a laboratory mouse (Mus musculus), seven laboratory rats (Rattus norvegicus) and a Syrian hamster (Mesocricetus auratus) in Düsseldorf and Heidelberg, Germany. The isolates are genotypically and phenotypically distinct from all previously described Rodentibacter species. Sequence analysis of 16S rRNA and rpoB gene sequences placed the isolates as a novel lineage within the genus Rodentibacter. In addition to the single-gene analysis, the whole genome sequence of the strain 1625/19T revealed distinct genome-to-genome distance values to the other Rodentibacter species. The genomic DNA G+C content of strain 1625/19T was 40.8 mol% within the range of Rodentibacter. At least six phenotypic characteristics separate the new isolates from the other Rodentibacter species, with Rodentibacter heylii being the most closely related. In contrast to the latter, the new strains display ß-haemolysis and are ß-glucuronidase, d-mannitol and sorbitol positive, but fail to produce lysine decarboxylase and trehalose. The genotypic and phenotypic differences between the novel strains and the other closely related strains of the genus Rodentibacter indicate that they represent a novel species within the genus Rodentibacter, family Pasteurellaceae, for which the name Rodentibacter haemolyticus sp. nov. is proposed. The type strain 1625/19T, (=DSM 111151T=CCM 9081T), was isolated in 2019 from the nose of a laboratory mouse (Mus musculus) in Düsseldorf, Germany.

Antrihabitans stalactiti gen. nov., sp. nov., a new member of the family Nocardiaceae isolated from a cave.

Two Gram-stain-positive, strictly aerobic, non-spore-forming actinobacterial strains, designated YC2-7T and YC5-17, were isolated from the Yongcheondonggul (larva cave) in Jeju, Republic of Korea and their taxonomic ranks were examined by a polyphasic approach. The 16S rRNA gene tree showed that the novel isolates occupied an independent position separated from recognized genera of the family Nocardiaceae. In the 92 core gene-based phylogenomic analysis, strain YC2-7T was loosely associated with the type strain of Aldersonia kummingensis with 66.2 % average amino acid identity. The 16S rRNA gene sequence simairity between the isolate and members of the family Nocardiaceae was below 96.7 %. The cell-wall peptidoglycan was meso-diaminopimelic acid as a diagnostic diamino acid. Whole-cell sugars consisted of arabinose, galactose and glucose. The predominant menaquinone was MK-8(H4, ω-cycl). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The cellular fatty acids consisted mainly of saturated and unsaturated components with small amounts of tuberculostearic acid. Mycolic acids of 52-58 carbon atoms were present. The DNA G+C content of the genome was 63.8 mol%. On the basis of combination of morphological and chemotaxonomic differences, in addition to phylogenetic distinctness, the novel isolates are considered to constitute members of a novel species of a new genus in the family Nocardiaceae, for which the name Antrihabitans stalactiti gen. nov., sp. nov. is proposed. The type strain is YC2-7T (=KACC 19965T=DSM 108733T).

Pseudomonas khazarica sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from Khazar Sea sediments.

A novel Gram-negative, aerobic, motile and rod-shaped bacterium with the potential to biodegrade polycyclic aromatic hydrocarbons, was isolated from Khazar (Caspian) Sea. Strain TBZ2T grows in the absence of NaCl and tolerates up to 8.5% NaCl. Growth occurred at pH 3.0-10.0 (optimum, pH 6.0-7.0) and 10-45 °C (optimum, 30 °C). The major fatty acids are C18:1ω7C, C16:1ω7C/ C15:0 iso 2-OH, C16:0, C12:0, C10:0 3-OH, C12:0 3-OH. The major polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and the predominant respiratory quinone is ubiquinone Q-9. The 16S rRNA gene sequence analysis showed that strain TBZ2T is a member of the genus Pseudomonas with the highest similarity to P. oleovorans subsp. oleovorans DSM 1045T (98.83%), P. mendocina NBRC 14162T (98.63%), P. oleovorans subsp. lubricantis RS1T (98.61%) and P. alcaliphila JCM 10630T (98.49%) based on EzBioCloud server. Phylogenetic analyses using housekeeping genes (16S rRNA, rpoD, gyrB and rpoB) and genome sequences demonstrated that the strain TBZ2T formed a distinct branch closely related to the type strains of P. mendocina and P. guguanensis. Digital DNA-DNA hybridisation and average nucleotide identity values between strain TBZ2T and its closest relatives, P. mendocina NBRC 14162T (25.3%, 81.5%) and P. guguanensis JCM 18146T (26.8%, 79.0%), rate well below the designed threshold for assigning prokaryotic strains to the same species. On the basis of phenotypic, chemotaxonomic, genomic and phylogenetic results, it is recommended that strain TBZ2T is a novel species of the genus Pseudomonas, for which the name Pseudomonas khazarica sp. nov., is proposed. The type strain is TBZ2T (= LMG 29674T = KCTC 52410T).

Leucobacter muris sp. nov., isolated from the nose of a laboratory mouse.

A Gram-stain-positive, rod-shaped, aerobic, non-motile, white, opaque bacterial isolate, designated 924/12T, was isolated from the nose of a laboratory mouse in Düsseldorf, Germany. The 16S rRNA gene sequence analyses indicated the phylogenetic position of the strain within the genus Leucobacter. Similarity levels over 97 % were recorded between the 16S rRNA gene sequence of strain 924/12T and the type strains of the species Leucobacter chironomi DSM 19883T (99.5 %), followed by Leucobacter celersubsp. astrifaciens CBX151T (97.6 %), Leucobacter celersubsp. celer NAL101T (97.5 %), 'Leucobacter kyeonggiensis' F3-P9 (97.5 %), Leucobacter zeae CC-MF41T (97.3 %), Leucobacter chromiiresistens JG31T (97.1 %), Leucobacter triazinivorans JW-1T (97.1 %), Leucobacter corticis 2 C-7T (97.0 %) and Leucobacter aridicolis CIP108388T (97.0 %). DNA-DNA hybridization and whole genomic comparison, mandatory to taxonomically separate strain 924/12T from the type strain of L. chironomi, revealed similarity values of 40.4 and 30.8 %, respectively, thus below the threshold of 70 % recommended differentiating between species. The cell-wall amino acids of the novel isolate were diaminobutyric acid, alanine, glycine, threonine and glutamic acid. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipid and one unknown lipid, whereas the predominant menaquinones were MK-11 and MK-10. The genomic DNA G+C content of strain 924/12T was 70.6 mol%. Phylogenetic analyses based on the 16S rRNA gene sequences and the phenotypical differences between strain 924/12T and the other closely related type strains of the genus Leucobacter indicated that strain 924/12T represents a novel species within the genus Leucobacter, family Microbacteriaceae, for which the name Leucobacter muris sp. nov. is proposed. The type strain is 924/12T (=DSM 101948T=CCM 8761T).

Silvanigrella aquatica gen. nov., sp. nov., isolated from a freshwater lake, description of Silvanigrellaceae fam. nov. and Silvanigrellales ord. nov., reclassification of the order Bdellovibrionales in the class Oligoflexia, reclassification of the families Bacteriovoracaceae and Halobacteriovoraceae in the new order Bacteriovoracales ord. nov., and reclassification of the family Pseudobacteriovoracaceae in the order Oligoflexales.

The unusual chemo-organoheterotrophic proteobacterial strain MWH-Nonnen-W8redT was isolated from a lake located in the Black Forest (Schwarzwald), Germany, by using the filtration-acclimatization method. Phylogenetic analyses based on the 16S rRNA gene sequence of the strain could not provide clear hints on classification of the strain in one of the current classes of the phylum Proteobacteria. Whole-genome sequencing resulted in a genome size of 3.5 Mbp and revealed a quite low DNA G+C content of 32.6 mol%. In-depth phylogenetic analyses based on alignments of 74 protein sequences of a phylogenetically broad range of taxa suggested assignment of the strain to a new order of the class Oligoflexia. These analyses also suggested that the order Bdellovibrionales should be transferred from the class Deltaproteobacteria to the class Oligoflexia, that this order should be split into two orders, and that the family Pseudobacteriovoracaceae should be transferred from the order Bdellovibrionales to the order Oligoflexales. We propose to establish for strain MWH-Nonnen-W8redT (=DSM 23856T=CCUG 58639T) the novel species and genus Silvanigrella aquatica gen. nov., sp. nov. to be placed in the new family Silvanigrellaceae fam. nov. of the new order Silvanigrellales ord. nov.

Description of Gramella forsetii sp. nov., a marine Flavobacteriaceae isolated from North Sea water, and emended description of Gramella gaetbulicola Cho et al. 2011.

Strain KT0803T was isolated from coastal eutrophic surface waters of Helgoland Roads near the island of Helgoland, North Sea, Germany. The taxonomic position of the strain, previously known as 'Gramella forsetii' KT0803, was investigated by using a polyphasic approach. The strain was Gram-stain-negative, chemo-organotrophic, heterotrophic, strictly aerobic, oxidase- and catalase-positive, rod-shaped, motile by gliding and had orange-yellow carotenoid pigments, but was negative for flexirubin-type pigments. It grew optimally at 22-25 °C, at pH 7.5 and at a salinity between 2-3 %. Strain KT0803T hydrolysed the polysaccharides laminarin, alginate, pachyman and starch. The respiratory quinone was MK-6. Polar lipids comprised phosphatidylethanolamine, six unidentified lipids and two unidentified aminolipids. The predominant fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω7c and iso-C17 : 1ω7c, with smaller amounts of iso-C15 : 0 2-OH, C15 : 0, anteiso-C15 : 0 and C17 : 1ω6c. The G+C content of the genomic DNA was 36.6 mol%. The 16S rRNA gene sequence identities were 98.6 % with Gramella echinicola DSM 19838T, 98.3 % with Gramella gaetbulicola DSM 23082T, 98.1 % with Gramella aestuariivivens BG-MY13T and Gramella aquimixticola HJM-19T, 98.0 % with Gramella lutea YJ019T, 97.9 % with Gramella portivictoriae DSM 23547T and 96.9 % with Gramella marina KMM 6048T. The DNA-DNA relatedness values were <35 % between strain KT0803T and type strains with >98.2 % 16S rRNA gene sequence identity. Based on the chemotaxonomic, phenotypic and genomic characteristics, strain KT0803T has been assigned to the genus Gramella, as Gramella forsetii sp. nov. The type strain is KT0803T (=DSM 17595T=CGMCC 1.15422T). An emended description of Gramella gaetbulicolaCho et al. 2011 is also proposed.

Sphingomonas jeddahensis sp. nov., isolated from Saudi Arabian desert soil.

A novel Sphingomonas strain was isolated from a sample of desert soil collected near Jeddah in Saudi Arabia. A polyphasic approach was performed to characterize this strain, initially designated as G39T. Cells of strain G39T are motile, Gram-negative, catalase- and oxidase-positive. The strain is able to grow aerobically at 20-35 °C, pH 6.5-8 and tolerates up to 4 % (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the closest relative type strains of G39T are Sphingomonas mucosissima DSM 17494T (98.6 %), S. dokdonensis DSM 21029T (98.4 %) and S. hankookensis DSM 23329T (97.4 %). Furthermore, the average nucleotide identities between the draft genome sequence of strain G39T and the genome sequences of all other available and related Sphingomonas species are significantly below the threshold of 94 %. The G+C content of the draft genome (3.12 Mbp) is 65.84 %. The prevalent (>5 %) cellular fatty acids of G39T were C18 : 1ω7c, C16 : 1ω7c and/or C16 : 1ω6c, C14 : 0 2-OH and C16 : 0. The only detectable respiratory quinone was ubiquinone-10 and the polar lipids profile is composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, as well as unidentified lipids, phospholipids and glycolipids. The results of the conducted polyphasic approach confirmed that this isolate represents a novel species of the genus Sphingomonas, for which the name Sphingomonas jeddahensis sp. nov. is proposed. The type strain of this species is G39T (=DSM 103790T=LMG 29955T).

Hydrobacter penzbergensis gen. nov., sp. nov., isolated from purified water.

A Gram-negative, oxidase- and catalase-positive bacterium, designated strain EM 4(T), which varied in shape from rod-shaped to curved or helical with frequently observed bulb-shaped protuberances, was isolated from purified water. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the family Chitinophagaceae within the phylum Bacteroidetes; the closest relative among bacterial species with validly published names was determined to be Sediminibacterium salmoneum NBRC 103935(T), with 93.4 % sequence identity. The main fatty acids of strain EM 4(T) were iso-C15 : 0, iso-C15 : 1 and iso-C17 : 0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, aminolipids, aminophospholipids and unknown lipids; the quinone system consisted of menaquinone MK-7. 16S rRNA gene sequence analysis and the polar lipid and fatty acid profiles suggest that the strain represents a novel genus and species, for which the name Hydrobacter penzbergensis gen. nov., sp. nov. is proposed. The type strain of Hydrobacter penzbergensis is strain EM 4(T) ( = DSM 25353(T) = CCUG 62278(T)).

Fontimonas thermophila gen. nov., sp. nov., a moderately thermophilic bacterium isolated from a freshwater hot spring, and proposal of Solimonadaceae fam. nov. to replace Sinobacteraceae Zhou et al. 2008.

A novel bacterial strain designated HA-01(T) was isolated from a freshwater terrestrial hot spring located at Hot Springs National Park, Arkansas, USA. Cells were Gram-negative-staining, rod-shaped, aerobic, chemo-organotrophic, oxidase- and catalase-positive, non-spore-forming and motile by means of a single polar flagellum. Growth occurred at 37-60 °C, with an optimum between 45 and 50 °C, and at pH 6.5-8.5, with an optimum between pH 6.5 and 7.0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the closest relatives of strain HA-01(T) were Solimonas aquatica NAA-16(T) (93.8 %), Solimonas flava CW-KD 4(T) (94.1 %), Solimonas soli DCY12(T) (93.1 %), Solimonas variicoloris MN28(T) (94.0 %), Nevskia ramosa Soe1(T) (91.2 %) and Hydrocarboniphaga effusa AP103(T) (91.1 %). Major fatty acids consisted of C(16 : 0), iso-C(16 : 0), C(16 : 1)ω5c and summed feature 8 (C(18 : 1)ω9c, C(18 : 1)ω7c and C(18 : 1)ω6c). Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and the major isoprenoid quinone was Q-8. The DNA G+C content was 64.4 mol%. Based on phylogenetic, phenotypic and chemotaxonomic evidence, it is proposed that strain HA-01(T) represents a novel species in a new genus for which the name Fontimonas thermophila gen. nov., sp. nov. is proposed. The type strain of the type species is HA-01(T) (= DSM 23609(T) = CCUG 59713(T)). A new family, Solimonadaceae fam. nov., is also proposed to replace Sinobacteriaceae Zhou et al. 2008.

Two New Rhizobiales Species Isolated from Root Nodules of Common Sainfoin (Onobrychis viciifolia) Show Different Plant Colonization Strategies.

Root nodules of legume plants are primarily inhabited by rhizobial nitrogen-fixing bacteria. Here, we propose two new Rhizobiales species isolated from root nodules of common sainfoin (Onobrychis viciifolia), as shown by core-gene phylogeny, overall genome relatedness indices, and pan-genome analysis. Mesorhizobium onobrychidis sp. nov. actively induces nodules and achieves atmospheric nitrogen and carbon dioxide fixation. This species appears to be depleted in motility genes and is enriched in genes for direct effects on plant growth performance. Its genome reveals functional and plant growth-promoting signatures, like a large unique chromosomal genomic island with high density of symbiotic genetic traits. Onobrychidicola muellerharveyae gen. nov. sp. nov. is described as a type species of the new genus Onobrychidicola in Rhizobiaceae. This species comprises unique genetic features and plant growth-promoting traits (PGPTs), which strongly indicate its function in biotic stress reduction and motility. We applied a newly developed bioinformatics approach for in silico prediction of PGPTs (PGPT-Pred), which supports the different lifestyles of the two new species and the plant growth-promoting performance of M. onobrychidis in the greenhouse trial. IMPORTANCE The intensive use of chemical fertilizers has a variety of negative effects on the environment. Increased utilization of biological nitrogen fixation (BNF) is one way to mitigate those negative impacts. In order to optimize BNF, suitable candidates for different legume species are required. Despite intensive search for new rhizobial bacteria associated with legumes, no new rhizobia have recently been identified from sainfoin (Onobrychis viciifolia). Here, we report on the discovery of two new rhizobial species associated with sainfoin, which are of high importance for the host and may help to increase sustainability in agricultural practices. We employed the combination of in silico prediction and in planta experiments, which is an effective way to detect promising plant growth-promoting bacteria.

Kroppenstedtia eburnea gen. nov., sp. nov., a thermoactinomycete isolated by environmental screening, and emended description of the family Thermoactinomycetaceae Matsuo et al. 2006 emend. Yassin et al. 2009.

A Gram-positive, spore-forming, aerobic, filamentous bacterium, strain JFMB-ATE(T), was isolated in 2008 during environmental screening of a plastic surface in grade C in a contract manufacturing organization in southern Germany. The isolate grew at temperatures of 25-50 °C and at pH 5.0-8.5, forming ivory-coloured colonies with sparse white aerial mycelia. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the family Thermoactinomycetaceae, except that the cell-wall peptidoglycan contained LL-diaminopimelic acid, while all previously described members of this family display this diagnostic diamino acid in meso-conformation. The DNA G+C content of the novel strain was 54.6 mol%, the main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol, and the major menaquinone was MK-7. The major fatty acids had saturated C14-C16 branched chains. No diagnostic sugars were detected. Based on the chemotaxonomic results and 16S rRNA gene sequence analysis, the isolate is proposed to represent a novel genus and species, Kroppenstedtia eburnea gen. nov. sp. nov. The type strain is JFMB-ATE(T) ( = DSM 45196(T)  = NRRL B-24804(T)  = CCUG 59226(T)).

Phylogenomics reveals the basis of adaptation of Pseudorhizobium species to extreme environments and supports a taxonomic revision of the genus.

The family Rhizobiaceae includes many genera of soil bacteria, often isolated for their association with plants. Herein, we investigate the genomic diversity of a group of Rhizobium species and unclassified strains isolated from atypical environments, including seawater, rock matrix or polluted soil. Based on whole-genome similarity and core genome phylogeny, we show that this group corresponds to the genus Pseudorhizobium. We thus reclassify Rhizobium halotolerans, R. marinum, R. flavum and R. endolithicum as P. halotolerans sp. nov., P. marinum comb. nov., P. flavum comb. nov. and P. endolithicum comb. nov., respectively, and show that P. pelagicum is a synonym of P. marinum. We also delineate a new chemolithoautotroph species, P. banfieldiae sp. nov., whose type strain is NT-26T (=DSM 106348T=CFBP 8663T). This genome-based classification was supported by a chemotaxonomic comparison, with increasing taxonomic resolution provided by fatty acid, protein and metabolic profiles. In addition, we used a phylogenetic approach to infer scenarios of duplication, horizontal transfer and loss for all genes in the Pseudorhizobium pangenome. We thus identify the key functions associated with the diversification of each species and higher clades, shedding light on the mechanisms of adaptation to their respective ecological niches. Respiratory proteins acquired at the origin of Pseudorhizobium were combined with clade-specific genes to enable different strategies for detoxification and nutrition in harsh, nutrient-poor environments.

Description of Chloramphenicol Resistant Kineococcus rubinsiae sp. nov. Isolated From a Spacecraft Assembly Facility.

A Gram-positive, coccoid, motile, aerobic bacterium, designated strain B12T was isolated from a Jet Propulsion Laboratory spacecraft assembly cleanroom, Pasadena, CA, United States. Strain B12T was resistant to chloramphenicol (100 µg/mL), and is a relatively slow grower (3-5 days optimal). Strain B12T was found to grow optimally at 28 to 32°C, pH 7 to 8, and 0.5% NaCl. Fatty acid methyl ester analysis showed that the major fatty acid of the strain B12T was anteiso C15 : 0 (66.3%), which is also produced by other Kineococcus species. However, arachidonic acid (C20 : 4 ω6,9,12,16c) was present in strain B12T and Kineococcus glutinatus YIM 75677T but absent in all other Kineococcus species. 16S rRNA analysis revealed that strain B12T was 97.9% similar to Kineococcus radiotolerans and falls within the Kineococcus clade. Low 16S rRNA gene sequence similarities (<94%) with other genera in the family Kineosporiaceae, including Angustibacter (93%), Kineosporia (94% to 95%), Pseudokineococcus (93%), Quadrisphaera (93%), and Thalassiella (94%) demonstrated that the strain B12T does not belong to these genera. Phylogenetic analysis of the gyrB gene show that all known Kineococcus species exhibited <86% sequence similarity with B12T. Multi-locus sequence and whole genome sequence analyses confirmed that B12T clades with other Kineococcus species. Average nucleotide identity of strain B12T were 75-78% with other Kineococcus species, while values ranged from 72-75% with species from other genera within family Kineosporiaceae. Average amino-acid identities were 66-72% with other Kineococcus species, while they ranged from 50-58% with species from other genera. The dDDH comparison of strain B12T genome with members of genera Kineococcus showed 20-22% similarity, again demonstrating that B12T is distantly related to other members of the genus. Furthermore, analysis of whole proteome deduced from WGS places strain B12T in order Kineosporiales, confirming that strain B12T is a novel member of family Kineosporiaceae. Based on these analyses and other genome characteristics, strain B12T is assigned to a novel species within the genus Kineococcus, and the name Kineococcus rubinsiae sp. nov., is proposed. The type strain is B12T (=FJII-L1-CM-PAB2T; NRRL B-65556T, DSM 110506T).

Sulfate-Reducing Bacteria That Produce Exopolymers Thrive in the Calcifying Zone of a Hypersaline Cyanobacterial Mat.

Calcifying microbial mats in hypersaline environments are important model systems for the study of the earliest ecosystems on Earth that started to appear more than three billion years ago and have been preserved in the fossil record as laminated lithified structures known as stromatolites. It is believed that sulfate-reducing bacteria play a pivotal role in the lithification process by increasing the saturation index of calcium minerals within the mat. Strain L21-Syr-ABT was isolated from anoxic samples of a several centimeters-thick microbialite-forming cyanobacterial mat of a hypersaline lake on the Kiritimati Atoll (Kiribati, Central Pacific). The novel isolate was assigned to the family Desulfovibrionaceae within the Deltaproteobacteria. Available 16S rRNA-based population surveys obtained from discrete layers of the mat indicate that the occurrence of a species-level clade represented by strain L21-Syr-ABT is restricted to a specific layer of the suboxic zone, which is characterized by the presence of aragonitic spherulites. To elucidate a possible function of this sulfate-reducing bacterium in the mineral formation within the mat a comprehensive phenotypic characterization was combined with the results of a comparative genome analysis. Among the determined traits of strain L21-Syr-ABT, several features were identified that could play a role in the precipitation of calcium carbonate: (i) the potential deacetylation of polysaccharides and consumption of substrates such as lactate and sulfate could mobilize free calcium; (ii) under conditions that favor the utilization of formate and hydrogen, the alkalinity engine within the mat is stimulated, thereby increasing the availability of carbonate; (iii) the production of extracellular polysaccharides could provide nucleation sites for calcium mineralization. In addition, our data suggest the proposal of the novel species and genus Desulfohalovibrio reitneri represented by the type strain L21-Syr-ABT (=DSM 26903T = JCM 18662T).

Comparing polysaccharide decomposition between the type strains Gramella echinicola KMM 6050(T) (DSM 19838(T)) and Gramella portivictoriae UST040801-001(T) (DSM 23547(T)), and emended description of Gramella echinicola Nedashkovskaya et al. 2005 emend. Shahina et al. 2014 and Gramella portivictoriae Lau et al. 2005.

Strains of the genus Gramella (family Flavobacteriacae, phylum Bacteroidetes) were isolated from marine habitats such as tidal flat sediments, coastal surface seawater and sea urchins. Flavobacteriaceae have been shown to be involved in the decomposition of plant and algal polysaccharides. However, the potential to decompose polysaccharides may differ tremendously even between species of the same genus. Gramella echinicola KMM 6050(T) (DSM 19838(T)) and Gramella portivictoriae UST040801-001(T) (DSM 23547(T)) have genomes of similar lengths, similar numbers of protein coding genes and RNA genes. Both genomes encode for a greater number of peptidases compared to 'G. forsetii'. In contrast to the genome of 'G. forsetii', both genomes comprised a smaller set of CAZymes. Seven polysaccharide utilization loci were identified in the genomes of DSM 19838(T) and DSM 23547(T). Both Gramella strains hydrolyzed starch, galactomannan, arabinoxylan and hydroxyethyl-cellulose, but not pectin, chitosan and cellulose (Avicel). Galactan and xylan were hydrolyzed by strain DSM 19838(T), whereas strain DSM 23547(T) hydrolyzed pachyman and carboxy-methyl cellulose. Conclusively, both Gramella type strains exhibit characteristic physiological, morphological and genomic differences that might be linked to their habitat. Furthermore, the identified enzymes mediating polysaccharide decomposition, are of biotechnological interest.

High quality draft genome sequence of Meganema perideroedes str. Gr1(T) and a proposal for its reclassification to the family Meganemaceae fam. nov.

Meganema perideroedes Gr1(T) is a filamentous bacterium isolated from an activated sludge wastewater treatment plant where it is implicated in poor sludge settleability (bulking). M. perideroedes is the sole described species of the genus Meganema and of the proposed novel family "Meganemaceae". Here we describe the features of the type strain Gr1(T) along with its annotated genome sequence. The 3,409,949 bp long draft genome consists of 22 scaffolds with 3,033 protein-coding and 59 RNA genes and is a part of Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes KMG project. Notably, genome annotation indicated the potential for facultative methylotrophy. However, the ability to utilize methanol as a carbon source could not be empirically demonstrated for the type strain or for in situ Meganema spp. strains.

Sequencing orphan species initiative (SOS): Filling the gaps in the 16S rRNA gene sequence database for all species with validly published names.

High quality 16S ribosomal RNA (rRNA) gene sequences from the type strains of all species with validly published names, as defined by the International Code of Nomenclature of Bacteria, are a prerequisite for their accurate affiliations within the global genealogical classification and for the recognition of potential new taxa. During the last few years, the Living Tree Project (LTP) has taken care to create a high quality, aligned 16S and 23S rRNA gene sequence database of all type strains. However, the manual curation of the sequence dataset and type strain information revealed that a total of 552 "orphan" species (about 5.7% of the currently classified species) had to be excluded from the reference trees. Among them, 322 type strains were not represented by an SSU entry in the public sequence repositories. The remaining 230 type strains had to be discarded due to bad sequence quality. Since 2010, the LTP team has coordinated a network of researchers and culture collections in order to improve the situation by (re)-sequencing the type strains of these "orphan" species. As a result, we can now report 351 16S rRNA gene sequences of type strains. Nevertheless, 201 species could not be sequenced because cultivable type strains were not available (121), the cultures had either been lost or were never deposited in the first place (66), or it was not possible due to other constraints (14). The International Code of Nomenclature of Bacteria provides a number of mechanisms to deal with the problem of missing type strains and we recommend that due consideration be given to the appropriate mechanisms in order to help solve some of these issues.

Complete genome sequence of Haliscomenobacter hydrossis type strain (O).

Haliscomenobacter hydrossis van Veen et al. 1973 is the type species of the genus Haliscomenobacter, which belongs to order "Sphingobacteriales". The species is of interest because of its isolated phylogenetic location in the tree of life, especially the so far genomically uncharted part of it, and because the organism grows in a thin, hardly visible hyaline sheath. Members of the species were isolated from fresh water of lakes and from ditch water. The genome of H. hydrossis is the first completed genome sequence reported from a member of the family "Saprospiraceae". The 8,771,651 bp long genome with its three plasmids of 92 kbp, 144 kbp and 164 kbp length contains 6,848 protein-coding and 60 RNA genes, and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.