International Journal of Systematic and Evolutionary Microbiology

Recently Hordt et al. 2020 proposed to merge Ochrobactrum and Brucella genera based on up to date phylogenomic evidence and overall genomic divergence among Brucella-Ochrobactrum clade. This led to the description of the new combinations Brucella ciceri comb. nov., basonym: Ochrobactrum ciceri Imran et al. 2010 and Brucella intermedia comb. nov., basonym: Ochrobactrum intermedium Velasco et al. 1998. However, the type species for Brucella ciceri DSM 22292T and Brucella intermedia LMG 3301T show whole-genome coherence at the species level (ANI = 98.21 %, Mash D = 0.0154006, dDDH relatedness >70%), suggesting that may belong to the same genomospecies. Also, both taxa formed a single clade in the phylogenomic tree based on single-copy gene sequences. Previously reported phenotypic data offer a context where both taxa are highly related supporting this synonymy. Therefore, Brucella ciceri should be reclassified as later heterotypic synonyms of Brucella intermedia, which has priority. The species description is consequently amended.

Strains of two novel Corynebacterium species were cultured from samples of human nostrils and skin collected in the United States and Botswana. These strains demonstrated growth on Columbia Colistin-Nalidixic Acid agar with 5% sheep blood and in liquid media (brain heart infusion and tryptic soy broth) supplemented with Tween 80, a source of the fatty acid oleic acid. Cells were Gram-positive, non-spore-forming, non-motile bacilli that showed catalase but not oxidase activity. Major fatty acids in both of these species were 18:1 {omega}9c (oleic acid), 16:0 (palmitic acid), and 18:0 (stearic acid). Analysis of the 16S ribosomal RNA gene sequences identified these strains as belonging to the genus Corynebacterium (family Corynebacteriaceae). Whole-genome sequencing revealed that these strains formed distinct branches on a phylogenomic tree, with C. tuberculostearicum being the closest relative but with average nucleotide identities of < 95% relative to all previously described species. These results indicate that these strains represent novel species of Corynebacterium, for which we propose the names Corynebacterium hallux sp. nov., with the type strain CTNIH22T (=ATCC TSD-435T=DSM 117774T), and Corynebacterium nasorum sp. nov., with the type strain KPL3804T (=ATCC TSD-439T=DSM 117767T). We also describe the characteristics of two strains isolated from human nasal passages that are members of the recently named species Corynebacterium yonathiae. RepositoriesThe sequencing files supporting the conclusions of this study are available in the Sequence Read Archive (PRJNA804245, PRJNA854648, PRJNA842433). The partial 16S ribosomal RNA gene sequences from PCR amplification and Sanger sequencing are available in GenBank for Corynebacterium hallux sp. nov. CTNIH22T (accession number: PQ252679) and Corynebacterium nasorum sp. nov. KPL3804T (accession number: PQ149068). The annotated genomic sequences for the strains characterized in this study have been deposited in GenBank with the following accession numbers: C. hallux sp. nov. CTNIH22T (GCF_032821755.1), C. nasorum sp. nov. KPL3804T (GCF_037908315.1), C. nasorum sp. nov. MSK185 (GCF_030229765.1), C. yonathiae KPL2619 (GCF_037908465.1), and C. yonathiae MSK136 (GCF_022288805.2).

A Gram-positive, obligately anaerobic coccobacillus, with the white raised circular colony was isolated from the cecum of feral chickens in Brookings, South Dakota, USA. The 16S rRNA gene sequence analysis suggested that the closest species to strain SW178 was Ruminococcus torques ATCC 27756T (96.94% similarity) that belongs to the family Lachnospiraceae. The genome of strain SW178 is 3.18 Mbp with G+C content of 46.9 mol%. Based on the phylogenetic and phenotypic comparison, we propose that strain SW178 be assigned to the genus Ruminococcus as a novel species, for which the name Ruminococcus catenae is proposed. The type strain is SW178 (= CCOS 1886 T, =DSM 109242T).

The Escherichia genus comprises four species and at least five lineages currently not assigned to any species, termed Escherichia cryptic clades. We isolated an Escherichia strain from an international traveller and resolved the complete DNA sequence of the chromosome and an IncI multi-drug resistance plasmid using Illumina and Nanopore whole-genome sequencing (WGS). Strain OPT1704T can be differentiated from existing Escherichia spp. using biochemical (VITEK2) and genomic tests (average nucleotide identity [ANI] and digital DNA:DNA hybridisation [dDDH]). Phylogenetic analysis based on alignment of 16S rRNA sequences and 682 concatenated core genes showed similar results. Our analysis further revealed that strain OPT1704T falls within Escherichia cryptic clade IV, and is closely related to cryptic clade III. Combining our analyses with publicly available WGS data of cryptic clades III and IV from Enterobase confirmed the close relationship between clades III and IV (>96% interclade ANI), warranting assignment of both clades to the same novel species. We propose E. ruysiae sp. nov. as a novel species, encompassing Escherichia cryptic clades III and IV (type strain OPT1704T = NCCB 100732T = NCTC 14359T). Author notesThe Genbank accession number for the 16S rRNA gene sequence of strain OPT1704T is LR745848. The Genbank accession number for the complete genome sequence of strain OPT1704T is CABVLQ000000000.

Anaerobic gut fungi (AGF, Neocallimastigomycota) are a clade of basal, zoospore-producing fungi within the subkingdom Chytridiomyceta and known inhabitants of the alimentary tract of animal hosts. To date, 22 genera and 38 species have been described, most originating from herbivorous mammals. Here, we report on the isolation and characterization of a novel species of Neocallimastigomycota from an avian host. Multiple AGF strains were isolated from ostrich feces obtained from a local farm in Oklahoma (USA). All strains formed small, irregular-shaped white colonies with darker centers, displayed a filamentous rhizoidal structure with monocentric thallus developmental patterns, and produced mostly monoflagellated zoospores. The type strain produced terminal sporangia that were predominantly globose, often exhibiting cup-shaped, and occasionally elongated sporangiophores. Sporangiophores characteristically exhibited constrictions at irregular intervals, giving them a pearls-on-a-chain-like appearance. Phylogenetic analysis using the D1-D2 region of the LSU rRNA gene (D1-D2 LSU), ribosomal internal transcribed spacer-1 (ITS1), and RNA polymerase II large subunit (RPB-II) grouped all isolates as a separate species within the genus Piromyces. Transcriptomic analysis indicated an average amino acid identity (AAI) of 80.34 % ({+/-} 3.27 %) between the type species and members of the genus Piromyces, and 62.93-76.05 % between the type species and all other AGF taxa outside Piromyces. Based on the morphology, phylogenetic analysis, and AAI values, we propose accommodating these strains as a novel species of Piromyces for which the name Piromyces struthionis is proposed. The type strain for this species is Ost1.

A Gram-positive and obligately anaerobic bacterium was isolated from cecal content of feral chickens in Brookings, South Dakota, USA. The microorganism grew at 37-45{degrees} C and pH 6-7.5. This strain produced acetic acid as the primary metabolic end product. Major fatty acids were C12:0, C14:0, C14:0 DMA and summed feature 1 (C13:1 at 12-13 and C14:0 aldehyde). Phylogenetic analyses based on 16S rRNA gene sequence suggested that strain SW165 belongs to the family Atopobiaceae with the closest relatives being Olsenella profusa DSM 13989T (96.33% similarity), Olsenella umbonate DSM 26220T (96.18%) and Olsenella uli DSM 7084T (96.03%). Genome sequencing revealed a genome size of 2.43 Mbp with a G+C content of 67.59 mol%, which is the highest G+C content among members of the genus Olsenella. Phylogenetic and phenotypic comparison indicated that strain SW165 represents a novel species of the genus Olsenella, for which the name Olsenella lakotia sp. nov. is proposed. The type strain is SW165 (=DSM 107283T).

A group of six clinical isolates previously identified as Corynebacterium diphtheriae biovar Belfanti, isolated from human cutaneous or peritoneum infections and from one dog, were characterized by genomic sequencing, biochemical analysis and mass spectrometry (MALDI-TOF MS). The six isolates were negative for the diphtheria toxin gene. Phylogenetic analyses showed that the six isolates (including FRC0190T) are clearly demarcated from C. diphtheriae, C. belfantii, C. ulcerans and C. pseudotuberculosis. The average nucleotide identity of FRC0190T with C. diphtheriae NCTC 11397T was 92.6%, and was 91.8% with C. belfantii FRC0043T. C. diphtheriae subsp. lausannense strain CHUV2995T appeared to be a later heterotypic synonym of C. belfantii (ANI, 99.3%). Phenotyping data revealed an atypical negative or heterogeneous intermediate maltose fermentation reaction for the six isolates. MALDI-TOF MS differentiated the new group from the other Corynebacterium taxa by the presence of specific spectral peaks. rpoB sequences showed identity to atypical, maltose-negative C. diphtheriae biovar Belfanti isolates previously described from two cats in the USA. We propose the name Corynebacterium rouxii sp. nov. for the novel group, with FRC0190T (= CIP 111752T = DSM 110354T) as type strain.

Xanthomonas and Stenotrophomonas are closely related genera in the family Lysobacteraceae. In our previous study of aroid-associated bacterial strains, most strains isolated from anthurium, and other aroids were reclassified as X. phaseoli and other Xanthomonas species. However, two strains from Spathiphyllum and Colocasia were phylogenetically distant from other strains in the Xanthomonas clade and two anthurium strains clustered within the Stenotrophomonas clade. Phylogenetic trees based on 16S rRNA and nine housekeeping genes placed the former strains with type strain of X. sacchari from sugarcane and the latter strains with type strain of S. bentonitica from bentonite. In pairwise comparisons with type strains, the overall genomic relatedness indices required delineation of new species; digital DNA-DNA hybridization and average nucleotide identity values were lower than 70% and 95%, respectively. Hence, three new species are proposed: S. aracearum sp. nov. and S. oahuensis sp. nov. for two anthurium strains, and X. hawaiiensis sp. nov. for the spathiphyllum and colocasia strains. The genome size of X. hawaiiensis sp. nov. is [~]4.88 Mbp and higher than S. aracearum sp. nov. (4.33 Mbp) and S. oahuensis sp. nov. (4.68 Mbp). Pan and core-genome analyses revealed 426 and 576 core genes present in 40 xanthomonads and 25 stenotrophomonads, respectively. The average number of unique genes in Stenotrophomonas spp. was higher than in Xanthomonas spp. implying higher genetic diversity in Stenotrophomonas.

We present the description of the new species, Rhodococcus (Prescottella) parequi, found during phylogenomic investigations of a global collection of strains identified as Rhodococcus (Prescottella) equi. Strain PAM 2766 was isolated from horse-breeding farm soil in Normandy, France, and was indistinguishable from R. equi based on the usual identification tests. Whole-genome phylogenetic analyses located PAM 2766 in the same Rhodococcus sublineage as R. equi, together with Rhodococcus agglutinans, Rhodococcus defluvii, Rhodococcus soli, Rhodococcus subtropicus, Rhodococcus spongiicola and Rhodococcus xishaensis. PAM 2766 is most closely related to, but sufficiently distinct from R. equi DSM 20307T to be considered as a separate species. Average Nucleotide Identity (ANI) and Average Amino Acid Identity (AAI) values are 88.60% and 92.35, respectively, well below the species cutoff. The PAM 2766 draft genome is [~]5.3 Mb in size with 68.98% G+C mol content. PAM 2766T is aerobic, non-motile, and produces smooth creamy to buff-coloured colonies very similar to those of R. equi. It phenotypically differs from the latter by the ability to grow at 5{degrees}C, a strongly positive urease test at 24 h, and specificities in the carbon and nitrogen source utilization profile as determined by phenotype microarray screens. Our data indicate that PAM 2766 belongs to a novel species, for which the name Rhodococcus parequi sp. nov. is proposed. R. parequi was avirulent in macrophage infection assays and is assumed to be non-pathogenic. The type strain is PAM 2766T (=CETC 30995T = NCTC 14987T).

Bacterial pathogens identified as Dickeya sp. have recently been associated with a corm rot of wetland taro on Oahu, Hawaii, but the species designation of these strains was unclear. A Gram-negative, pectinolytic bacterial strain PL65T isolated from an infected taro corm was subjected to polyphasic analysis to determine its genomic and phenotypic characteristics. Multi-locus sequence analyses (MLSA) based on five housekeeping genes (dnaA, gapA, gyrB, atpD, and purA) revealed that Dickeya zeae and D. oryzae, were the closest relatives. Phylogenetic analysis based on 463 core gene sequences clearly showed two potentially new species within Dickeya oryzae. In silico DNA- DNA hybridization value of strain PL65T with 12 Type strains of Dickeya species was <68%. Average nucleotide identity (ANI) analysis revealed that PL65T was at the margin of the species delineation cut-off values with a 96% ANI value. The metabolic profile of strain PL65T using BIOLOG differentiated it from the type strains of all other known species of Dickeya. Based on the results of genome-to-genome comparisons and phenotypic data presented in this report, we propose establishment of a new species, Dickeya colocasiae sp. nov. with strain PL65T as the type strain (ICMP 24361T).

Streptomycetaceae is one of the oldest families within phylum Actinobacteria and it is large and diverse in terms of number of described taxa. The members of the family are known for their ability to produce medically important secondary metabolites and antibiotics. In this study, strains showing low 16S rRNA gene similarity (&lt;97.3 %) with other members of Streptomycetaceae were identified and subjected to phylogenomic analysis using 33 orthologous gene clusters (OGC) for accurate taxonomic reassignment resulted in identification of eight distinct and deeply branching clades, further average amino acid identity (AAI) analysis showed lower AAI values or AAI within the range of 60-80 % which was previously observed in related but different genera of bacteria. The whole genome phylogeny based on concatenated core genes and AAI analyses supported the claim that those phylogenetically distinct members may be assigned to 8 novel genera namely Actinoacidiphila, Actinomesophilus, Charcoactinospora, Curviacidiphilus, Kafeoacidiphilus, Mangroviactinospora, Peterkaempfera, and Streptantibioticus. In addition, based on the core genome phylogeny and 16S rRNA tree topology and distinct chemotaxonomic and physiological properties, the sequence belonged to Streptomyces thermoautotrophicus was assigned to a novel genera Charcoactinospora which is placed under novel family Charcoactinosporaceae. Lastly, a clade comprising of strains that showed high 16S rRNA gene similarity (100 %) with similar tree topology in phylogenetic trees was subjected to overall genome related indices analyses such as digital DNA – DNA hybridization, and average nucleotide identity that supported the claim that Streptomyces asterosporus is a later heterotypic synonym of Streptomyces calvus.Competing Interest StatementThe authors have declared no competing interest.AbbreviationsOGCOrthologous gene clusterAAIaverage amino acid identitydDDHdigital DNA-DNA hybridizationANIaverage nucleotide identityView Full Text

We report the complete genome sequences of eight Fusobacterium watanabei clinical isolates, ranging from 1.95 to 2.09 Mbp. Analysis against the Genome Taxonomy Database (GTDB) indicates that Fusobacterium watanabei genomes are part of the "Fusobacterium nucleatum_J" group, which also encompasses the previously published FNU strain and Fna C1 isolates.

Goniomonads are heterotrophic representatives of Cryptista, sister lineage to the phototrophic Cryptists. Goniomonads are morphologically and genetically diverse, comprising nine genera described so far. Besides morphologically described genera, SSU rDNA sequencing data has revealed the existence of at least one more monophyletic genus-level lineage within goniomonads, as well as more novel species within the described genera. Furthermore, the diversity of SSU rDNA sequences within goniomonads is not fully investigated, and addition of novel sequences can be crucial for understanding the evolution and diversity of goniomonads and for providing a basis for taxonomic descriptions. The morphological data record available for goniomonads is relatively limited: many cellular features remain undescribed, or described only for a few isolates. In this study, we describe the new genus and species Ebisugoniomonas hispanica n. gen. n. sp., and two novel species within Poseidogoniomonas: P. posteriocircus n. sp. and P. zopfkaesiformis n. sp. We report a range of observations on the cellular features of goniomonads: periplast plate arrangement pattern and intracellular structures. We also update the SSU rDNA phylogeny of goniomonads by adding sequences from novel isolates and environmental DNA studies. Several sequences recovered from novel isolates and environmental DNA datasets likely represent highly divergent lineages of goniomonads in the SSU rDNA phylogeny.

Strain LLG6346-3.1T, isolated from the thallus of the brown alga Ericaria zosteroides collected in Mediterranean Sea near Bastia in Corsica, France, was characterized using a polyphasic method. Cells were Gram-stain-negative, strictly aerobic, non-flagellated, motile by gliding, rod-shaped and grew optimally at 30-33 {degrees}C, at pH 8-8.5 and with 4-5 % NaCl. Strain LLG6346-3.1T used the seaweed polysaccharide alginic acid as sole carbon source which was vigorously liquefied. Phylogenetic analyses showed that the bacterium is affiliated to the genus Zobellia (family Flavobacteriaceae, class Flavobacteriia). Strain LLG6346-3.1T exhibited 16S rRNA gene sequence similarity values of 98.5 and 98.3 % to the type strains of Zobellia russellii and Zobellia roscoffensis respectively, and of 97.4-98.2 % to other species of the genus Zobellia. The DNA G+C content of strain LLG6346-3.1T was determined to be 38.28 mol%. Digital DNA-DNA hybridization predictions by the ANI and GGDC methods between strain LLG6346-3.1T and other members of the genus Zobellia showed values of 76-88 %, and below 37 %, respectively. The phenotypic, phylogenetic and genomic analyses show that strain LLG6346-3.1T is distinct from species of the genus Zobellia with validly published names and that it represents a novel species of the genus Zobellia, for which the name Zobellia alginoliquefaciens sp. nov. is proposed. The type strain is LLG6346-3.1T (RCC 7657T = LLG 32918T).

The objective of this study was to re-analyse the molecular phylogeny and/or the morphology of all species, which have been attributed to the so-far mono-generic fungal family Ambisporaceae. The genus Ambispora has been well-known for its spore bi-morphy described even from single spore clusters. Triple-walled spores are differentiated on sporiferous saccules, while mono-walled spores are formed on simple subtending hyphae. New phylogenetic analyses reveal dissimilarities of [&ge;]10% in partial nrDNA gene of three different stable phylogenetic clades and thus suggest the division of Ambispora into three genera, which simultaneously request for advanced morphological separations. These advances are primarily based on the more diverse spore wall composition of the ambisporoid-acaulosporoid morph rather than on the rather simple-glomoid morph. While all known species of the triple-walled morph have an evanescent to semi-permanent outer spore wall, i) Am. fennica, Am. brasiliensis, Am. gerdemannii and Am. nicolsonii have a smooth, permanent central spore wall (Am. fennica clade, A), ii) the central wall of Am. appendicula, Am. callosa, Am. leptoticha and Am. jimgerdemannii is alveolate (Am. appendicula clade, B), and iii) the central wall of Am. granatensis is smooth, but easily degraded, thus rather short-lived and not permanent but evanescent (Am. granatensis clade, C). In conclusion, species of the Am. fennica clade represent the genus Ambispora, while species of the Am. appendicula clade represent the new genus Appendiculaspora, and the mono-specific Am. granatensis clade represents the new genus Ephemerapareta. Species of an additional morph, with triple-walled spores, but apparently formed on subtending hyphae, and having a diagnostic reticulate, football-like middle wall, are here separated from the revised genus Ambispora based solely on morphological analyses, since molecular identification analyses so far failed and remained merely unknown. This later morph and genus is based on the type species Pelotaspora reticulata comb. nov, and on P. austrolatina sp. nov. Concomitant molecular phylogenetic and morphological analyses are needed to attribute not only Pelotaspora spp., but also those species, for which hitherto only the ambisporoid-glomoid morph has been observed correctly within the family Ambisporaceae. Without molecular analyses, such species with glomoid but unknown ambisporoid-acaulosporoid morph have to be retained within Ambispora.

Ascomycetous yeasts belong to Saccharomycotina and Taphrinomycotina, with about 1,200 described species distributed worldwide. More than 300 ascomycetous yeast species have been reported from China, which indicates that China possesses a hotspot with high yeast diversity. However, our knowledge of yeast diversity and distribution remains limited, and this area needs to be explored in depth. Here we describe 77 new ascomycetous yeast species with 195 isolates obtained over the past two decades during the continuous yeast diversity surveys in China, based on the phylogenetic analyses of the sequences of D1/D2 domains of the large subunit (LSU) and the internal transcribed spacer region including the 5.8S rDNA (ITS) of the nuclear ribosomal DNA (rDNA). The average nucleotide identity (ANI) analysis was used to delimitate closely related species with low sequence heterogeneity in the ITS and D1/D2 regions. Seventy-five of these new species belong to 35 genera in the Saccharaomycotina, while the other two are distributed in Taphrina of the Taphrinomycotina. In addition, we propose two new genera, namely Gaboromyces gen. nov. and Yurkovozyma gen. nov.

The Pectobacteriaceae family comprises plant pathogens able to provoke diverse diseases, including plant maceration due to the production of pectinases disrupting the plant cell wall. To better understand their natural diversity, a survey of pectinolytic bacteria was performed in lakes of the French region La Camargue near the Mediterranean Sea. Sixteen atypical pectinolytic isolates were obtained from brackish water of three lakes. The genome of six isolates was sequenced; their size is around 4.8 to 5.0 Mb, including a plasmid of 59 to 61 kb; their G+C values range from 49.1 to 49.3 mol%. Phylogenetic analyses indicated that the novel strains formed a new clade of Pectobacteriaceae, separate from previously described genera of this family. These analyses suggested also that Acerihabitans does not belong to Pectobacteriaceae and should be reclassified in the Bruguierivoracaceae family, while Symbiopectobacterium could be a true Pectobacteriaceae member. Based on phenotypic, genomic and phylogenetic characteristics, we propose the creation of a new genus with the name Prodigiosinella gen. nov. Both the phenotypic and phylogenetic analyses separated the strains into two distinct subgroups. However, the DNA-DNA relatedness values revealed a close relationship between the two groups, supporting their appurtenance to the same species. Thus, it is proposed to classify them as two subspecies of Prodigiosinella aquatilis sp. nov., for which we propose the name Prodigiosinella aquatilis subsp. aquatilis ssp. nov. (LS101T = CFBP 8826T = LMG 32072T) and Prodigiosinella aquatilis subsp. natabilis ssp. nov. (CE70T = CFBP 9054T = LMG 32867T).

The present study described the comparative genomic analysis of the validly named species of the genus Pseudomonas to define the taxonomic assignment. Genomic information for 208 type strains was available in the NCBI genome database at the time of conducting this analysis. The ANI, AAI and in silico DNA DNA hybridization (isDDH) data were higher than the threshold values for the twelve strains with their closely related type species. Whole genome comparisons shared 97 - 99 % average nucleotide identity, 97.85 to 99.19 % average amino acid identity and 72.80 to 90.40 % digital DNA DNA hybridization values. Further, the phylogenomic analysis based on the core genome confirmed that P. humi CCA1 and P. citronellolis LMG 18378, P. zeshuii KACC 15471 and P. luteola NBRC 103146, P. oryzihabitans DSM 6835 and P. psychrotolerans DSM 15758, P. nitroreducens DSM 14399 and P. nitritireducens WZBFD3-5A2, P. fluvialis CCM 8778 and P. pharmacofabricae ZYSR67-Z, P. panacis DSM 18529 and P. marginalis DSM 13124 formed a monophyletic clade. Thus, we proposed six type species viz., P. humi CCA1, P. zeshuii KACC 15471, P. psychrotolerans DSM 15758, P. nitritireducens WZBFD3 5A2, P. pharmacofabricae ZYSR67 Z and P. panacis DSM 18529 are the later heterotypic synonym of P. citronellolis Lang 2007, P. luteola, P. oryzihabitans, P. nitroreducens Lang 2007, P. fluvialis and P. marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980), respectively considering the priority date of publication.

Genome sequence-based identification of two strains (3986T and 51.81) isolated from rabbits in France in 1972 and 1981 and deposited in the Collection of Institut Pasteur (CIP) has led to the description of a novel species in the genus Neisseria. The cells of both strains were non-motile, Gram-stain-negative and diplococcobacilli. Optimal growth on trypticase soy agar was recorded at 37{degrees}C and pH 8.5 in aerobic conditions. Phylogeny based on 16S rRNA gene placed the strains close to Neisseria bacilliformis ATCC BAA-1200T (96.38%) nesting with the members of Neisseriaceae family. Furthermore, the phylogenetic analysis based on bac120 gene set from the Genome Taxonomy Database (GTDB) placed both strains within the monophyletic Neisseria clade, which also included type strains of Morococcus cerebrosus, Bergeriella denitrificans, Kingella potus, Uruburuella suis and Uruburuella testudinis. However, Neisseria shayeganii strain 871T was placed outside Neisseria clade and close to the members of Eikenella genus. Strains 3986T and 51.81 were placed in a branch distinct from all species of the genus Neisseria and exhibited the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values below the species demarcation values. In contrast, ANI value within the two strains was 96.9% confirming that they represent same species. The genomic DNA G+C content of strain 3986T was 56.92%. Based on the phylogenetic and phenotypic data, the strains 3986T and 51.81 represent a novel species of the genus Neisseria, for which the name Neisseria leonis sp. nov. is proposed (type strain 3986T = CIP 109994T = LMG 32907T). Additionally, based on phylogenetic analysis, DUS dialect and average amino acid identity (AAI) values, we also proposed the reclassification of Morococcus cerebrosus, Bergeriella denitrificans, Kingella potus, Uruburuella suis and Uruburuella testudinis into Neisseria genus and Neisseria shayeganii into Eikenella genus. Author NotesThe GenBank accession numbers for the 16S rRNA gene sequence of strains 3986T and 51.81 are respectively OQ121838.1 and OQ428162.1. The draft genome sequences have been deposited in GenBank under the accession numbers JAPQFK000000000 (strain 3986T) and JAPQFL000000000 (strain 51.81). Further explanations mentioned in the article as well as 7 supplementary tables and 7 supplementary figures are available with the online version of this article.

Ancyromonads are small biflagellated protists with a bean-shaped morphology. They are cosmopolitan in marine, freshwater and soil environments, where they attach to surfaces while feeding on bacteria. These poorly known grazers stand out by their uncertain phylogenetic position in the tree of eukaryotes, forming a deep-branching orphan lineage that is considered key to better understanding the early evolution of eukaryotes. Despite their ecological and evolutionary interest, only limited knowledge exists about their true diversity. Here, we aimed to better characterise ancyromonads by integrating environmental surveys with behavioural observation and description of cell morphology, for which sample isolation and culturing is indispensable. We studied 18 ancyromonad strains, including 14 new isolates and 7 new species. Most of them belong to three new and genetically divergent genera: Caraotamonas, Nyramonas, and Olneymonas (encompassing 4 species). The remaining three new species belong to the already known genera Fabomonas and Ancyromonas. We also raised Striomonas, formerly a subgenus of Nutomonas, to full genus status, based on morphological and phylogenetic grounds. For all these new species, we studied their morphology under light and electron microscopy and carried out molecular phylogenetic analyses, including as well 18S rRNA gene sequences from several environmental surveys. Based on these analyses, we have updated the taxonomy of Ancyromonadida.