Definition of the symbiovar viciae in the species Rhizobium azibense and biogeographic implications.

Vicia faba L. (faba bean) is a legume cultivated worldwide which commonly establishes effective symbiosis with the symbiovar viciae of species from the Rhizobium leguminosarum phylogenetic group. However, on the basis of the rrs, recA, and atpD gene phylogenies, in this work we identified a strain named EFBRI 42 nodulating V. faba as Rhizobium azibense. This is the first report on the nodulation of Vicia by R. azibense which commonly nodulates P. vulgaris and to date encompasses strains harboring the nodC genes typical of the symbiovars gallicum and phaseoli. However, the strain EFBRI 42 carries a nodC gene typical of the symbiovar viciae for which we report here by the first time this symbiovar in R. azibense. This finding showed the existence of symbiotic genes horizontal transfer events during the coevolution of R. azibense with P. vulgaris and V. faba in their respective distribution centers of Mesoamerica and the Middle East.

Endophytic Bosea spartocytisi sp. nov. Coexists with rhizobia in root nodules of Spartocytisus supranubius growing in soils of Teide National Park (Canary Islands).

Two rod-shaped Gram negative strains, SSUT16T and SSUT22, were isolated from root nodules of Spartocytisus supranubius in soils of the Teide National Park (Tenerife, Spain). The 16S rRNA gene sequences of these two novel strains classified them within genus Bosea with similarity values ranging from 97.65 % to 99.54 % with respect to the other species of this genus. The MLSA analysis from a concatenation of the two housekeeping- genes, recA and gyrB, showed that Bosea thiooxidans LMG 26210T and B. robiniae LMG 26381T are the two closest relative species with which they share similarity sequences values of 94.42 % and 94.27 %, respectively. The genome sequence analysis of strain SSUT16T showed average nucleotide identity percentages (ANIb) and digital DNA-DNA hybridization (dDDH) below 84 % and 33 %, respectively, with the type strains of all sequenced species of genus Bosea. These values are much lower than the currently accepted cut-off values for these two parameters to delineate bacterial species, confirming that the novel strains constitute a novel Bosea species. In addition, they are also distinguished from the other closest species in their fatty acid composition and in other phenotypic characteristics. Genome sequence analysis showed the absence of the common nodulation and nitrogen fixation genes in the novel strains. Therefore, based on the results of phylogenetic, genomic, chemotaxonomic and phenotypic characterization, we propose a new species named Bosea spartocytisi sp. nov., with type strain SSUT16T (=LMG 32510T = CECT 30526T = HAMBI 3759T).

Rhizobium croatiense sp. nov. and Rhizobium redzepovicii sp. nov., two new species isolated from nodules of Phaseolus vulgaris in Croatia.

Phaseolus vulgaris is a legume indigenous to America which is nodulated by strains of genus Rhizobium in Croatia. Four of these strains, 13TT, 9T, 18TT and 8Z are phylogenetically close to the species from the Rhizobium leguminosarum phylogenetic complex in the 16S rRNA gene analysis. The results of both the analyses of the concatenated recA and atpD genes and whole genomes revealed that the strains 13TT and 9T clustered with Rhizobium sophoriradicis CCBAU 03470T and the strains 18TT and 8Z with Rhizobium ecuadorense CNPSO 671T. Whole genome average nucleotide identity blast (ANIb) and dDDH values between the strains 13TT and the type strain of R. sophoriradicis and between the strains 18TT and the type strain of R. ecuadorense were lower than 95% and 70%, respectively, which are the threshold values recommended for bacterial species differentiation. These results combined with those of chemotaxonomic and phenotypic analyses support the affiliation of these strains to two novel species within the genus Rhizobium for which we propose the names Rhizobium croatiense sp. nov. 13TT (=LMG 32397T, = HAMBI 3740T) as type strain and Rhizobium redzepovicii sp. nov. 18TT (=LMG 32398T, = HAMBI 3741T) as type strain.

Agrobacterium leguminum sp. nov., isolated from nodules of Phaseolus vulgaris in Spain.

Two endophytic strains, coded MOVP5T and MOPV6, were isolated from nodules of Phaseolus vulgaris plants grown on agricultural soil in Southeastern Spain, and were characterized through a polyphasic taxonomy approach. Their 16S rRNA gene sequences showed 99.3 and 99.4 %, 98.9 and 99.6 %, and 99.0 and 98.7% similarity to 'A. deltaense' YIC 4121T, A. radiobacter LGM 140T, and A. pusense NRCPB10T, respectively. Multilocus sequence analysis based on sequences of recA and atpD genes suggested that these two strains could represent a new Agrobacterium species with less than 96.5 % similarity to their closest relatives. PCR amplification of the telA gene, involved in synthesis of protelomerase, confirmed the affiliation of strains MOPV5T and MOPV6 to the genus Agrobacterium. Whole genome average nucleotide identity and digital DNA-DNA hybridization average values were less than 95.1 and 66.7 %, respectively, with respect to its closest related species. Major fatty acids in strain MOPV5T were C18 : 1 ω7c/C18 : 1 ω6c in summed feature 8, C19 : 0 cyclo ω8c, C16 : 0 and C16 : 0 3-OH. Colonies were small to medium, pearl-white coloured on YMA at 28 °C and growth was observed at 10-42 °C, pH 5.0-10.0 and with 0.0-0.5 % (w/v) NaCl. The DNA G+C content was 59.9 mol%. These two strains differ from all other genomovars of Agrobacterium found so far, including those that have not yet given a Latin name. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strain MOPV5T as representing a novel species of Agrobacterium, for which the name Agrobacterium leguminum sp. nov. is proposed. The type strain is MOPV5T (=CECT 30096T=LMG 31779T).

Definition of the novel symbiovar canariense within Mesorhizobium neociceri sp. nov., a new species of genus Mesorhizobium nodulating Cicer canariense in the "Caldera de Taburiente" National Park (La Palma, Canary Islands).

Cicer canariense is a highly promiscuous wild chickpea nodulated by Mesorhizobium strains in La Palma Island located at Canary archipelago. Four of these strains, CCANP34, CCANP35T, CCANP38 and CCANP95 belong to a group phylogenetically close to Mesorhizobium caraganae with 100% similarity values in the 16S rRNA gene. However, the genomes of the strains CCANP35T and M. caraganae LMG 24397T obtained in this work showed ANIb and dDDH values of 90.02% and 44.1%, respectively. These values are lower than those currently accepted for different bacterial species showing that the Canarian strains do not belong to the species M. caraganae. The Canarian strains also differ from M. caraganae in the amounts of several fatty acids and in several phenotypic traits. Based on the obtained results the Canarian strains belong to a novel species for which we propose the name Mesorhizobium neociceri sp. nov. and whose type strain is CCANP35T. The results of the phylogenetic analyses of nodC and nifH symbiotic genes showed that the Canarian strains represent a novel symbiovar within genus Mesorhizobium phylogenetically divergent to that encompassing M. caraganae. We propose the names canariense and caraganae for the symbiovars encompassing the strains of M. neociceri and M. caraganae, respectively.

Defining the Rhizobium leguminosarum Species Complex.

Bacteria currently included in Rhizobium leguminosarum are too diverse to be considered a single species, so we can refer to this as a species complex (the Rlc). We have found 429 publicly available genome sequences that fall within the Rlc and these show that the Rlc is a distinct entity, well separated from other species in the genus. Its sister taxon is R. anhuiense. We constructed a phylogeny based on concatenated sequences of 120 universal (core) genes, and calculated pairwise average nucleotide identity (ANI) between all genomes. From these analyses, we concluded that the Rlc includes 18 distinct genospecies, plus 7 unique strains that are not placed in these genospecies. Each genospecies is separated by a distinct gap in ANI values, usually at approximately 96% ANI, implying that it is a 'natural' unit. Five of the genospecies include the type strains of named species: R. laguerreae, R. sophorae, R. ruizarguesonis, "R. indicum" and R. leguminosarum itself. The 16S ribosomal RNA sequence is remarkably diverse within the Rlc, but does not distinguish the genospecies. Partial sequences of housekeeping genes, which have frequently been used to characterize isolate collections, can mostly be assigned unambiguously to a genospecies, but alleles within a genospecies do not always form a clade, so single genes are not a reliable guide to the true phylogeny of the strains. We conclude that access to a large number of genome sequences is a powerful tool for characterizing the diversity of bacteria, and that taxonomic conclusions should be based on all available genome sequences, not just those of type strains.

Agrobacterium cavarae sp. nov., isolated from maize (Zea mays L.) roots.

A bacterial strain designated as RZME10T was isolated from a Zea mays L. root collected in Spain. Results of analysis of the 16S rRNA gene sequence showed that this strain belongs to the genus Agrobacterium with Agrobacterium larrymoorei ATCC 51759T being the most closely related species with 99.9 % sequence similarity. The similarity values of the rpoB, recA, gyrB, atpD and glnII genes between strain RZME10T and A. larrymoorei ATCC 51759T were 93.5, 90.0, 88.7, 87.9 and 90.1 %, respectively. The estimated average nucleotide identity using blast and digital DNA-DNA hybridization values between these two strains were 80.4 and 30.2 %, respectively. The major fatty acids of strain RZME10T are those from summed feature 8 (C18 : 1 ω6c/C18 : 1 ω7c) and C16 : 0. Pathogenicity tests on tomato and carrot roots showed that strain RZME10T was not able to induce plant tumours. Based on the results of genomic, chemotaxonomic and phenotypic analyses, we propose that strain RZME10T represents a novel species named Agrobacterium cavarae sp. nov. (type strain RZME10T=CECT 9795T=LMG 31257T).

Strain ATCC 4720T is the authentic type strain of Agrobacterium tumefaciens, which is not a later heterotypic synonym of Agrobacterium radiobacter.

The original type strains of Agrobacterium radiobacter and Agrobacterium tumefaciens recorded in the eighth edition of Bergey's Manual of Determinative Bacteriology published in 1974 were NCIB 9042T and ATCC 4720T, respectively. However, in the list of the valid names of bacteria compiled in 1980, both strains were changed, A. radiobacter NCIB 9042T to ATCC 19358T and A. tumefaciens ATCC 4720T to ATCC 23308T. These changes were unjustified, particularly in the case of A. tumefaciens whose type strain was replaced by another strain from the same collection, although the original type strain ATCC 4720T was never lost and it is currently available in several culture collections. Therefore, we request that the type strain of A. tumefaciens be corrected from ATCC 23308T to ATCC 4720T.

Rhizobium ruizarguesonis sp. nov., isolated from nodules of Pisum sativum L.

Four strains, coded as UPM1132, UPM1133T, UPM1134 and UPM1135, and isolated from nodules of Pisum sativum plants grown on Ni-rich soils were characterised through a polyphasic taxonomy approach. Their 16S rRNA gene sequences were identical and showed 100% similarity with their closest phylogenetic neighbors, the species included in the 'R. leguminosarum group': R. laguerreae FB206T, R. leguminosarum USDA 2370T, R. anhuiense CCBAU 23252T, R. sophoreae CCBAU 03386T, R. acidisoli FH13T and R. hidalgonense FH14T, and 99.6% sequence similarity with R. esperanzae CNPSo 668T. The analysis of combined housekeeping genes recA, atpD and glnII sequences showed similarities of 92-95% with the closest relatives. Whole genome average nucleotide identity (ANI) values were 97.5-99.7% ANIb similarity among the four strains, and less than 92.4% with closely related species, while digital DNA-DNA hybridization average values (dDDH) were 82-85% within our strains and 34-52% with closely related species. Major fatty acids in strain UPM1133T were C18:1 ω7c / C18:1 ω6c in summed feature 8, C14:0 3OH/ C16:1 iso I in summed feature 2 and C18:0. Colonies were small to medium, pearl-white coloured in YMA at 28°C and growth was observed in the ranges 8-34°C, pH 5.5-7.5 and 0-0.7% (w/v) NaCl. The DNA G+C content was 60.8mol %. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strains UPM1132, UPM1133T, UPM1134 and UPM1135 into a novel species of Rhizobium, for which the name Rhizobium ruizarguesonis sp. nov. is proposed. The type strain is UPM1133T (=CECT 9542T=LMG 30526T).

Genome Analysis of Endobacterium cerealis, a Novel Genus and Species Isolated from Zea mays Roots in North Spain.

In the present work, we analyse the genomic and phenotypic characteristics of a strain named RZME27T isolated from roots of a Zea mays plant grown in Spain. The phylogenetic analyses of 16S rRNA gene and whole genome sequences showed that the strain RZME27T clustered with the type strains of Neorhizobium galegae and Pseudorhizobium pelagicum from the family Rhizobiaceae. This family encompasses several genera establishing symbiosis with legumes, but the genes involved in nodulation and nitrogen fixation are absent in its genome. Nevertheless, genes related to plant colonization, such as those involved in motility, chemotaxis, quorum sensing, exopolysaccharide biosynthesis and hydrolytic enzymes production were found. The comparative pangenomic analyses showed that 78 protein clusters present in the strain RZME27T were not found in the type strains of its closest relatives N. galegae and P. pelagicum. The calculated average nucleotide identity (ANI) values between the strain RZME27T and the type strains of N. galegae and P. pelagicum were 75.61% and 75.1%, respectively, similar or lower than those found for other genera from family Rhizobiaceae. Several phenotypic differences were also found, highlighting the absence of the fatty acid C19:0 cyclo ω8c and propionate assimilation. These results support the definition of a novel genus and species named Endobacterium cerealis gen. nov. sp. nov. whose type strain is RZME27T.

History and current taxonomic status of genus Agrobacterium.

The genus Agrobacterium was created a century ago by Conn who included it in the family Rhizobiaceae together with the genus Rhizobium. Initially, the genus Agrobacterium contained the non-pathogenic species Agrobacterium radiobacter and the plant pathogenic species Agrobacterium tumefaciens and Agrobacterium rhizogenes. At the end of the past century two new pathogenic species, Agrobacterium rubi and Agrobacterium vitis, were added to the genus. Already in the present century these species plus Agrobacterium larrymoorei were reclassified into genus Rhizobium. This reclassification was controversial and for a time both genus names were used when new species were described. Few years ago, after a taxonomic revision based on genomic data, the old species A. rhizogenes was maintained in the genus Rhizobium, the old species A. vitis was transferred to the genus Allorhizobium and several Rhizobium species were transferred to the genus Agrobacterium, which currently contains 14 species including the old species A. radiobacter, A. tumefaciens, A. rubi and A. larrymoorei. Most of these species are able to produce tumours in different plants, nevertheless the genus Agrobacterium also encompasses non-pathogenic species, one species able to nodulate legumes and one human pathogenic species. Taking into account that the species affiliations to five Agrobacterium genomospecies have not been determined yet, an increase in the number of species within this genus is expected in the near future.

The Mimosoid tree Leucaena leucocephala can be nodulated by the symbiovar genistearum of Bradyrhizobium canariense.

Leucaena leucocephala is a Mimosoid legume tree indigenous to America that has spread to other continents, although it is not still present in some European countries such as Portugal. Nevertheless, we found that this legume can be nodulated in this country by slow-growing rhizobial strains which were identified as Bradyrhizobium canariense trough the analysis of the core genes recA and glnII. The analysis of the symbiotic gene nodC showed that these strains belong to the symbiovar genistearum, which commonly nodulates Genistoid legumes. Although two strains nodulating L. leucocephala in China and Brazil were classified within the genus Bradyrhizobium, they belong to undescribed species and to the symbiovars glycinearum and tropici, respectively. Therefore, we report here for the first time the ability of L. leucocephala to establish symbiosis with strains of B. canariense sv genistearum confirming the high promiscuity of L. leucocephala, that allows it to establish symbiosis with rhizobia native to different continents increasing its invasiveness potential.

Phylogenetic diversity of rhizobia nodulating Phaseolus vulgaris in Croatia and definition of the symbiovar phaseoli within the species Rhizobium pisi.

Phaseolus vulgaris is a legume indigenous to America which is currently cultivated in Europe including countries located at the Southeast of this continent, such as Croatia, where several local landraces are cultivated, most of them of Andean origin. In this work we identify at species and symbiovar levels several fast-growing strains able to form effective symbiosis with P. vulgaris in different Croatian soils. The identification at species level based on MALDI-TOF MS and core gene sequence analysis showed that most of these strains belong to the species R. leguminosarum, R. hidalgonense and R. pisi. In addition, several strains belong to putative new species phylogenetically close to R. ecuadorense and R. sophoriradicis. All Croatian strains belong to the symbiovar phaseoli and harbour the α and γ nodC alleles typical for American strains of this symbiovar. Nevertheless, most of Croatian strains harboured the γ nodC gene allele supporting its Andean origin since it is also dominant in other European countries, where Andean cultivars of P. vulgaris are traditionally cultivated, as occurs in Spain. The only strains harbouring the α nodC allele belong to R. hidalgonense and R. pisi, this last only containing the symbiovars viciae and trifolii to date. This is the first report about the presence in Europe of the species R. hidalgonense, the nodulation of P. vulgaris by R. pisi and the existence of the symbiovar phaseoli within this species. These results significantly increase the knowledge of the biogeography of Rhizobium-P. vulgaris symbiosis.

The N-fixing legume Periandra mediterranea constrains the invasion of an exotic grass (Melinis minutiflora P. Beauv) by altering soil N cycling.

Melinis minutiflora is an invasive species that threatens the biodiversity of the endemic vegetation of the campo rupestre biome in Brazil, displacing the native vegetation and favouring fire spread. As M. minutiflora invasion has been associated with a high nitrogen (N) demand, we assessed changes in N cycle under four treatments: two treatments with contrasting invasion levels (above and below 50%) and two un-invaded control treatments with native vegetation, in the presence or absence of the leguminous species Periandra mediterranea. This latter species was considered to be the main N source in this site due to its ability to fix N2 in association with Bradyrhizobia species. Soil proteolytic activity was high in treatments with P. mediterranea and in those severely invaded, but not in the first steps of invasion. While ammonium was the N-chemical species dominant in plots with native species, including P.mediterranea, soil nitrate prevailed only in fully invaded plots due to the stimulation of the nitrifying bacterial (AOB) and archaeal (AOA) populations carrying the amoA gene. However, in the presence of P. mediterranea, either in the beginning of the invasion or in uninvaded plots, we observed an inhibition of the nitrifying microbial populations and nitrate formation, suggesting that this is a biotic resistance strategy elicited by P. mediterranea to compete with M. minutiflora. Therefore, the inhibition of proteolytic activity and the nitrification process were the strategies elicited by P.mediterranea to constrain M.munitiflora invasion.

Pseudomonas edaphica sp. nov., isolated from rhizospheric soil of Cistus ladanifer L. in Spain.

During a study on biodiversity of bacteria inhabiting rhizospheric soil of rockrose (Cistus ladanifer L.), we isolated a strain coded RD25T in a soil from Northern Spain. The 16S rRNA gene sequence showed 99.5 % identity with respect to the closest related species Pseudomonas brenneri DSM15294T, and 99.4 % with respect to P. paralactis WS4672T. The following related Pseudomonas species showed 99.3 % or less identity, and therefore RD25T was classified within genus Pseudomonas. The phylogenetic analysis of 16S rRNA and the housekeeping genes rpoB, rpoD and gyrB suggested that this strain could be a novel species. The strain RD25T has several polar-subpolar flagella. It can grow at 36 °C, at 0-6 % NaCl concentration and a range of pH 5-9. Positive for arginine dihydrolase and urease production, and negative for reduction of nitrate. The strain is catalase and oxidase positive. Major fatty acids are C16 : 1 ω7c / C16 : 1 ω6c in summed feature 3, C16 : 0, and C18 : 1 ω7c / C18 : 1 ω6c in summed feature 8. The respiratory ubiquinone is Q9. The DNA G+C content was 59.9 mol%. The digital DNA-DNA hybridisation average values (dDDH) ranged between 30-61.2 % relatedness and the ANIb values ranged between 93.9-80.5 % with respect to the type strains of the closely related species. Therefore, the genotypic, genomic, phenotypic and chemotaxonomic data support the classification of strain RD25 as a novel species of genus Pseudomonas, for which the name P. edaphica sp. nov. is proposed. The type strain is RD25T (=LMG 30152T=CECT 9373T).

Minimal standards for the description of new genera and species of rhizobia and agrobacteria.

Herein the members of the Subcommittee on Taxonomy of Rhizobia and Agrobacteria of the International Committee on Systematics of Prokaryotes review recent developments in rhizobial and agrobacterial taxonomy and propose updated minimal standards for the description of new species (and genera) in these groups. The essential requirements (minimal standards) for description of a new species are (1) a genome sequence of at least the proposed type strain and (2) evidence for differentiation from other species based on genome sequence comparisons. It is also recommended that (3) genetic variation within the species is documented with sequence data from several clearly different strains and (4) phenotypic features are described, and their variation documented with data from a relevant set of representative strains. Furthermore, it is encouraged that information is provided on (5) nodulation or pathogenicity phenotypes, as appropriate, with relevant gene sequences. These guidelines supplement the current rules of general bacterial taxonomy, which require (6) a name that conforms to the International Code of Nomenclature of Prokaryotes, (7) validation of the name by publication either directly in the International Journal of Systematic and Evolutionary Microbiology or in a validation list when published elsewhere, and (8) deposition of the type strain in two international culture collections in separate countries.

Aquella oligotrophica gen. nov. sp. nov.: A new member of the family Neisseriaceae isolated from laboratory tap water.

A bacterial strain designated as P08T was isolated from laboratory tap water during a water quality assessment in University of Malaya, Malaysia. The strain was a Gram-negative, rod-shaped, nonmotile, and aerobic bacterium. Complete genome of P08T comprised of a 2,820,660 bp chromosome with a G + C content of 36.43%. Both 16S rRNA phylogeny and phylogenetic tree inferred from the core gene matrix demonstrated that P08T formed a hitherto unknown subline within the family Neisseriaceae. Ortho average nucleotide identity (OrthoANI) values and the percentage of conserved proteins (POCP) calculated from complete genome sequence indicated low relatedness between P08T and its phylogenetic neighbors. Respiratory quinone analysis revealed Q-8 as the only detectable quinone. The predominant cellular fatty acids were identified as C14:0 , iso-C15:0 , and summed feature 3 (C16:1 ω7c/C16:1 ω6c). The polar lipids consisted of uncharacterized aminolipid, phosphatidylglycerol, and phosphatidylethanolamine. All aspects of phenotypic and phylogenetic data suggested that strain P08T represents a novel genus within family Neisseriaceae, for which the name Aquella gen. nov. is proposed. The type species of the genus is Aquella oligotrophica sp. nov., and the type strain is P08T (=LMG 29629T =DSM 100970T ).

Bacillus safensis subsp. osmophilus subsp. nov., isolated from condensed milk, and description of Bacillus safensis subsp. safensis subsp. nov.

A bacterial strain, designated BC09T, was isolated from a contaminated sample of condensed milk. Phylogenetic analyses based on 16S rRNA gene sequences placed strain BC09T into the genus Bacillus with its closest relatives being Bacillus safensis and Bacillus australimaris with 100 and 99.9 % similarity, respectively. Analysis of the gyrB gene confirmed the closeness of strain BC09T with respect to the species B. safensis since it presented 97.8 and 95.2 % similarity values, respectively, to the type strains of B. safensis and B. australimaris. DNA-DNA hybridization confirmed these results showing averages of 67 and 56 %, respectively, between strain BC09T and the type strains of B. safensis and B. australimaris. Average nucleotide identity blast values obtained for BC09T compared to the closest relative type strains were 95.7 and 67.6 %, respectively, and predicted DNA-DNA hybridization values were 93.1 and 51.9 %, respectively. However, strain BC09T differs from the type strains of its closest relatives in several phenotypic characteristics. MK-7 was the only menaquinone detected and iso-C15:0 and anteiso-C15:0 were the major fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids, two unidentifed glycolipids, three unidentified lipids and one unidentifed phosphoglycolipid. Meso-diaminopimelic acid was detected in the peptidoglycan. The G+C content was 40.9 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain BC09T represents a new subspecies of B. safensis, for which the name Bacillus safensis subsp. osmophilus subsp. nov. is proposed. The type strain is BC09T (=LMG 30124T, =CECT 9344T).

Phyllobacterium salinisoli sp. nov., isolated from a Lotus lancerottensis root nodule in saline soil from Lanzarote.

A Gram-negative rod, designated strain LLAN61T, was isolated from a root nodule of Lotus lancerottensis growing in a saline soil sample from Lanzarote (Canary Islands). The strain grew optimally at 0.5 % (w/v) NaCl and tolerated up to 3.5 %. The 16S rRNA gene sequence analysis showed that strain LLAN61T belonged to genus Phyllobacterium and that Phyllobacteriumleguminum ORS 1419T and Phyllobacteriummyrsinacearum IAM 13584T are the closest related species with 97.93 and 97.86% similarity values, respectively. In the atpD phylogeny, P. leguminum ORS 1419T and P. myrsinacearum ATCC 43591T, sharing similarities of 87.6 and 85.8% respectively, were also the closest species to strain LLAN61T. DNA-DNA hybridization showed an average value of 21 % between strain LLAN61T and P. leguminum LMG 22833T, and 6 % with P. myrsinacearum ATCC 43590T. The predominant fatty acids were C19 : 0 cyclo ω8c and C18 : 1ω6c/C18 : 1ω7c (summed feature 8). The DNA G+C content was 58.0 mol%. Strain LLAN61T differed from its closest relatives in some culture conditions and in assimilation of several carbon sources. Based upon the results of phylogeny, DNA-DNA hybridization, phenotypic tests and fatty acid analysis, this strain should be classified as a novel species of Phyllobacterium for which the name Phyllobacterium salinisoli sp. nov. is proposed (type strain LLAN61T=LMG 30173T = CECT 9417T).

The current status on the taxonomy of Pseudomonas revisited: An update.

The genus Pseudomonas described in 1894 is one of the most diverse and ubiquitous bacterial genera which encompass species isolated worldwide. In the last years more than 70 new species have been described, which were isolated from different environments, including soil, water, sediments, air, animals, plants, fungi, algae, compost, human and animal related sources. Some of these species have been isolated in extreme environments, such as Antarctica or Atacama desert, and from contaminated water or soil. Also, some species recently described are plant or animal pathogens. In this review, we revised the current status of the taxonomy of genus Pseudomonas and the methodologies currently used for the description of novel species which includes, in addition to the classic ones, new methodologies such as MALDI-TOF MS, MLSA and genome analyses. The novel Pseudomonas species described in the last years are listed, together with the available genome sequences of the type strains of Pseudomonas species present in different databases.