International journal of systematic and evolutionary microbiology最新文献

{"title":"<i>Companilactobacillus miaonis</i> sp. nov. - a novel bacterium isolated from zha-chili.","authors":"Jiangping Wu, Dongying Ge, Zhuang Guo, Qiangchuan Hou, Huijun Zhao, Chengcong Yang, Dingwu Qu, Yurong Wang","doi":"10.1099/ijsem.0.007211","DOIUrl":"10.1099/ijsem.0.007211","url":null,"abstract":"<p><p>Two Gram-positive, rod-shaped bacteria, designated as strains HBUAS56257^T and HBUAS59544, were isolated from zha-chili. Both strains were found to be catalase-negative and facultatively aerobic. Moreover, both HBUAS56257^T and HBUAS59544 grew optimally at a temperature of 25-40 °C and a pH of 4-6 in the presence of 2-10% NaCl. The major fatty acids in these microbes were C_16:0 and C_18:1 ω9c, with intraspecific variations observed in the relative abundances of summed feature 7 and C19:0 iso. The DNA G+C contents were 36.06 mol% and 36.10 mol%, respectively. Based on 16S rRNA gene and other genomic sequences, HBUAS56257^T and HBUAS59544 were found to exhibit the closest relatedness to <i>Companilactobacillus suantsaicola</i> NBRC 113530^T and <i>Companilactobacillus alimentarius</i> DSM 20249^T. Phylogenetic analyses, based on both the 16S rRNA gene and 81 housekeeping genes, showed that the strains shared distinct phylogenetic lineages within the genus <i>Companilactobacillus</i>. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values indicated that strains HBUAS56257^T and HBUAS59544 belong to the same species. However, when compared to the type strains of other <i>Companilactobacillus</i> species, both dDDH and ANI values fell below the established prokaryotic species delineation thresholds (typically ≤70% for dDDH and ≤95-96% for ANI). Moreover, unlike the type strains of closely related species, HBUAS56257^T and HBUAS59544 fermented d-galactose and l-rhamnose. Based on these phenotypic, chemotaxonomic and phylogenetic data, we concluded that strains HBUAS56257^T and HBUAS59544 represent a novel species within the genus <i>Companilactobacillus</i>, hereby named <i>Companilactobacillus miaonis</i> sp. nov., with HBUAS56257^T (= KCTC 21229^T= GDMCC 1.4547^T) being the type strain of <i>C. miaonis</i>.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148317288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Metabacillus harenarius</i> sp. nov., an alginate lyase-producing bacterium, and reclassification of '<i>Bacillus weihaiensis</i>'.","authors":"Rongting Liang, Kunlian Mo, Zhuobing Zhao, Yonghua Hu, Zheng Zhang, Mingguo Jiang, Huiqin Huang","doi":"10.1099/ijsem.0.007185","DOIUrl":"10.1099/ijsem.0.007185","url":null,"abstract":"<p><p>A Gram-stain-negative, motile, rod-shaped, alginate lyase-producing bacterium, designated HB246100^T, was isolated from coastal sand sample collected from Luhuitou Scenic Area, Sanya, China. The strain grew at 15-50 ℃ (optimum, 35 ℃), pH 6.0-11.0 (optimal, pH 8.0) and 0-10% (w/v) NaCl (optimum, 3%). The predominant isoprenoid quinone was found to be menaquinone 7, and the major fatty acids were anteiso-C_15 : 0, iso-C_15 : 0, iso-C_14 : 0 and iso-C_16 : 0. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified lipid, three unidentified phospholipids and three unidentified glycolipids. The size of the genome was 4.29 Mbp, with a G+C content of 36.5 mol%. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain HB246100^T belonged to the genus <i>Metabacillus</i>, and the closest phylogenetically related type species were <i>Metabacillus crassostreae</i> JSM 100118^T, <i>Metabacillus schmidteae</i> Marseille-P9898^T, <i>Metabacillus halosaccharovorans</i> E33^T and Metabacillus litoralis SW-211^T with the identities of 98.9, 98.1, 98.0 and 98.0%, respectively. The phylogenetic tree based on 16S rRNA gene sequences and the phylogenomic tree based on core genome sequences indicated that the novel strain was most closely related to <i>M. crassostreae</i> and <i>M. litoralis</i>, with average nucleotide identity of 74.8-75.6% and digital DNA-DNA hybridization value of 22.1-22.4%. Comprehensive phenotypic, phylogenetic and genomic characteristics demonstrate that strain HB246100^T is distinct from the species with validly published names in the genus <i>Metabacillus</i>, suggesting that it represents a novel species of the genus <i>Metabacillus</i> and proposing the name <i>Metabacillus harenarius</i> sp. nov. The type strain is HB246100^T (=MCCC 1K09923^T=JCM 38130^T). Furthermore, '<i>Bacillus weihaiensis</i>' Alg07, which only publicly disclosed its genome sequence, was emended and reclassified as <i>M. harenarius</i>.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Fusobacterium abscessus</i> sp. nov., associated with brain abscess in humans.","authors":"Øyvind Kommedal, Diego Forni, Torbjørn Sæle Bruvold, Grete Dimmen, Marit Gjerde Tellevik, Siri Tandberg Knoop, Manuela Sironi, Audun Sivertsen","doi":"10.1099/ijsem.0.007199","DOIUrl":"10.1099/ijsem.0.007199","url":null,"abstract":"<p><p>Recent genome-based phylogenetic investigations of the <i>Fusobacterium nucleatum</i> group have revealed that genomes currently annotated as <i>F. nucleatum</i> (sensu stricto) bifurcate into two separate phylogenetic groups: a large cluster containing the <i>F. nucleatum</i> type strain and a smaller cluster possibly representing a novel species. To further investigate this, we searched our strain archive for <i>Fusobacterium</i> isolates potentially representing the smaller cluster. A strain Vestland17^T, cultured from a polymicrobial brain abscess, had been found to share less than 99% similarity with the <i>F. nucleatum</i> type strain by partial 16S rRNA gene sequencing. The isolate grew on blood agar with dry whitish colonies (0.5-1 mm) after 24-48 h of anaerobic incubation. Genome-based phylogenetic analyses confirmed that it belonged to the smaller <i>F. nucleatum</i> outlier cluster. We further confirmed the presence of this outlier cluster in four additional historic brain abscess samples using specific amplification and sequencing of the <i>dnaB</i> gene directly from remnant extracted DNA stored in our diagnostic biobank. A core-genome phylogenetic tree including the novel strain Vestland17^T and several more recent GenBank whole-genome references reproduced the previously observed bifurcation within the <i>F. nucleatum</i> (sensu stricto) species. Average Nucleotide Identities (ANI) between the two clusters are in the range 94.7-95.2%, supporting that the smaller cluster represents a different species as per a 95-96% ANI threshold. This was further supported by alternative strategies based on the biological species concept. For this species, we propose the name <i>Fusobacterium abscessus</i>. The type strain of <i>F. abscessus</i> is Vestland17^T (DSM 121298^T, NCTC 15275^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13262755/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148225178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Clavibacter vidaverae</i> sp. nov., <i>Clavibacter rahimiani</i> sp. nov. and <i>Clavibacter davisi</i> sp. nov.: corynebacterial plant pathogens isolated from small-grain cereals.","authors":"Asma Rahmanzadeh, S Mohsen Taghavi, Habibeh Hajian-Maleki, Hamid Abachi, Nastaran Zamani, Sadegh Zarei, Céline Mirguet, Martial Briand, Xiang Li, Nicolas W G Chen, Marie-Agnès Jacques, Perrine Portier, Ebrahim Osdaghi","doi":"10.1099/ijsem.0.007154","DOIUrl":"10.1099/ijsem.0.007154","url":null,"abstract":"<p><p>During 2020-2024, 25 Gram-positive actinobacterial strains were isolated from small-grain cereals in Iran. Colony morphology, phenotypic characteristics and multilocus sequence analyses showed that the strains belonged to the coryneform genus <i>Clavibacter</i> (family <i>Microbacteriaceae</i>). The <i>Clavibacter</i> strains isolated from small-grain cereals in Iran were distributed within five distinct phylogenetic clades. Two of those clades included <i>Clavibacter tessellarius</i> and <i>Clavibacter zhangzhiyongii</i>, while the other three groups of <i>Clavibacter</i> strains were taxonomically undetermined and phylogenetically distinct from all validly described species in the genus. Whole-genome sequence-based indices, i.e. average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH), showed that the latter three phylogenetic clades differed from all validly described <i>Clavibacter</i> species, with ANI/dDDH values <94% and <70%, respectively. Analyses of KEGG pathways and pathogenicity-associated genes revealed substantial differences among the five <i>Clavibacter</i> groups associated with small-grain cereals. All <i>Clavibacter</i> strains were capable of infecting their hosts of isolation, i.e. wheat, barley and oat. Thus, based on both phenotypic features, i.e. differences in colony morphology, biolog microbial identification microplate data and polar lipid repertoires, as well as DNA similarity indices, the three clades could represent three new species within <i>Clavibacter</i>. In this study, we provide formal species descriptions for three <i>Clavibacter</i> clades isolated from small-grain cereals. These three species include <i>Clavibacter vidaverae</i> sp. nov. (type strain Sh2088ᵀ=CFBP 9070ᵀ=ICMP 24732ᵀ), <i>Clavibacter rahimiani</i> sp. nov. (type strain Sh2141ᵀ=CFBP 9069ᵀ=ICMP 24735ᵀ) and <i>Clavibacter davisi</i> sp. nov. (type strain Sh2036ᵀ=CFBP 9071ᵀ=ICMP 24729ᵀ).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phylogenomics-based reclassification of <i>Brevibacterium celere</i> and <i>Brevibacterium sandarakinum</i> as later heterotypic synonyms of <i>Brevibacterium sanguinis</i> and <i>Brevibacterium picturae</i>, respectively.","authors":"Jasvinder Kaur, Jaspreet Kaur, Manali Bhardwaj, Vaishnavi Rajagopalan","doi":"10.1099/ijsem.0.007145","DOIUrl":"10.1099/ijsem.0.007145","url":null,"abstract":"<p><p>The present study used genome-based approaches to clarify the taxonomic status of four closely related species of the genus <i>Brevibacterium</i>. At the time of this study, genomic information for 36 validly published type strains with correct names was available. The 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization values for <i>Brevibacterium celere</i> KMM 3637^T and <i>Brevibacterium sanguinis</i> CF63^T are 99.26%, 98.64% and 88.20%, respectively. For the second pair, <i>Brevibacterium sandarakinum</i> 01-Je-003^T and <i>Brevibacterium picturae</i> LMG 22061^T, these values are 97.97%, 97.81% and 81.80%, respectively. These findings indicate that <i>B. celere</i> KMM 3637ᵀ and <i>B. sanguinis</i> CF63ᵀ belong to the same species, as do <i>B. sandarakinum</i> 01-Je-003ᵀ and <i>B. picturae</i> LMG 22061ᵀ. Based on these evidences, we propose the reclassification of <i>Brevibacterium celere</i> Ivanova <i>et al</i>. 2004 and <i>Brevibacterium sandarakinum</i> Kämpfer <i>et al</i>. 2010 as later heterotypic synonyms of <i>Brevibacterium sanguinis</i> Wauters <i>et al</i>. 2004 and <i>Brevibacterium picturae</i> Heyrman <i>et al</i>. 2004, respectively.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Formosa sejongensis</i> sp. nov. and <i>Polaromonas potterensis</i> sp. nov., isolated from King George Island, Antarctica.","authors":"Sumin Choi, Hyeon Seop Lee, Sinseong Park, Seong Yeol Choi, Wonsik Mun, Kyoung Lee, Jin Hyung Lee, Jeong-Eun Han, Robert J Mitchell","doi":"10.1099/ijsem.0.007150","DOIUrl":"10.1099/ijsem.0.007150","url":null,"abstract":"<p><p>Gram-negative, rod-shaped bacteria, designated as strains PL04ᵀ and SM01ᵀ, were isolated from King George Island, Antarctica. 16S rRNA gene sequence-based phylogenetic analysis indicated that strain PL04ᵀ belongs to the genus <i>Formosa</i> within the family <i>Flavobacteriaceae</i>. Pairwise 16S rRNA gene sequence comparison showed that <i>Formosa arctica</i> IMCC 9458ᵀ was the closest recognized relative (98.34% sequence similarity). Likewise, 16S rRNA gene sequence-based phylogenetic analysis revealed that strain SM01ᵀ is affiliated with the genus <i>Polaromonas</i> within the family <i>Comamonadaceae</i>, showing the highest sequence similarity to <i>Polaromonas ginsengisoli</i> Gsoil 115ᵀ (98.42%). The genomic DNA G+C contents of strains PL04ᵀ and SM01ᵀ were 32.8% and 61.81%, respectively. The major cellular fatty acids of PL04ᵀ and SM01^T were iso-C_15:0, iso-C_15:1 G [double peak identified as C_15:1 iso <i>ω</i>5<i>c</i> and C_15:1 iso <i>ω</i>10<i>c</i> by GC-mass spectrometry (MS)] and C_₁₆:0, summed feature 3 (identified as C_₁₆:1  <i>ω</i>7<i>c</i> by GC-MS), respectively. Based on the phenotypic and phylogenetic characteristics, strain PL04ᵀ is considered to represent a novel species of the genus <i>Formosa</i>, for which the name <i>Formosa sejongensis</i> sp. nov. is proposed, with PL04ᵀ (=KCTC 102051ᵀ=DSM 117045ᵀ) as the type strain. Similarly, strain SM01ᵀ is considered to represent a novel species of the genus <i>Polaromonas</i>, for which the name <i>Polaromonas potterensis</i> sp. nov. is proposed, with SM01ᵀ (=KCTC 8096ᵀ=DSM 116566ᵀ) as the type strain.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13148724/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive genome-centred taxonomy for agrobacteria and rhizobia in the <i>Bartonellaceae</i> and <i>Rhizobiaceae</i> families.","authors":"Melandré van Lill, Stephanus N Venter, Marike Palmer, Chrizelle W Beukes, Emma T Steenkamp","doi":"10.1099/ijsem.0.007125","DOIUrl":"10.1099/ijsem.0.007125","url":null,"abstract":"<p><p>To clarify the taxonomy of agrobacteria and rhizobia - assemblages of bacteria critical for sustainable agriculture and biotechnology - we applied a phylogenomic approach to reassess their current classifications. By phylogenetically analysing two marker gene sets based on both nucleotide (UBCG) and amino acid levels (bac120) of the type strains within the families <i>Bartonellaceae</i> and <i>Rhizobiaceae</i>, we found that both marker sets led to congruent phylogenies that consistently recovered the same lineages. These generic boundaries of the proposed lineages were strongly supported by average amino acid identities of ≥76%. Our results corroborate with previously proposed genus-level thresholds and provided a robust foundation for taxonomic revision. Several taxonomic changes are proposed to minimize the disruption to current classifications while also reflecting the evolutionary histories of these organisms. These include the emendation of '<i>Paramesorhizobium</i>' to better reflect its distinction from <i>Ochrobactrum</i> and <i>Phyllobacterium</i>. Two <i>Rhizobium</i> species were also reassigned to the novel genera <i>Fluviirhizobium</i> gen. nov. and <i>Phytoamicus</i> gen. nov., reflecting the deep phylogenetic divergence and distinct ecological origins. Other taxonomic refinements include new combinations for species previously assigned to <i>Rhizobium</i> and <i>Mesorhizobium</i>, now shown to belong to <i>Paenirhizobium</i> and <i>Terribium</i>. We further clarified the classifications of <i>Allorhizobium</i>, <i>Neorhizobium</i> and <i>Mesorhizobium sensu</i> GTDB that were based on relative evolutionary divergence and were likely too broad. This demonstrates the need for an integrative genome-based approach to classify organisms that do not solely rely on numerical thresholds to produce biologically meaningful groups that enhance taxonomic stability.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147837822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Brevundimonas sediminis</i> sp. nov., isolated from mangrove sediment.","authors":"Shijun Pan, Yejuan Yang, Lirui Liu, Huan Du, Yang Liu","doi":"10.1099/ijsem.0.007107","DOIUrl":"10.1099/ijsem.0.007107","url":null,"abstract":"<p><p>Two Gram-stain-negative, facultatively anaerobic, light-yellow, rod-shaped bacterial strains, designated as FT23028^T and FT23042, were isolated from mangrove sediment collected in Shenzhen, PR China. Their taxonomic positions were established using a polyphasic approach including phylogenetic, physiological, biochemical and chemotaxonomic analyses. Both strains grew optimally at 25-30 °C and pH 7.0 without NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains FT23028^T and FT23042 were most closely related to <i>Brevundimonas kwangchunensis</i> KCTC 12380^T (98.31 and 98.23%), <i>Brevundimonas lenta</i> KCTC 12871^T (98.10 and 98.03%) and <i>Brevundimonas viscosa</i> CGMCC 1.10683^T (97.68 and 97.61%), respectively. These two strains shared 99.93% 16S rRNA gene sequence similarity with each other. The predominant fatty acids (>10%) identified in strains FT23028^T and FT23042 were C_18:1  <i>ω</i>7c (and/or C_18:1  <i>ω</i>6c, 48.7 and 53.2%, respectively) and C_16:0 (29.9 and 26.4%, respectively). The polar lipid profiles included two unknown phosphoglycolipids, five glycolipids and three unidentified lipids. The respiratory quinone was Q-10. The total sequence lengths of strains FT23028^T and FT23042 were 3,122,877 and 3,235,296 bp, with DNA G+C contents of 65.3 and 67.4 mol%, respectively. Based on phenotypic, chemotaxonomic and phylogenetic distinction, a novel species of the genus <i>Brevundimonas</i> is proposed, for which the name <i>Brevundimonas sediminis</i> sp. nov. is suggested. The type strain is FT23028^T (=MCCC 1K09458^T=KCTC 8783^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147972570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Nanosynbacter lyticus</i> gen. nov., sp. nov., an ultrasmall, obligate epibiont bacterium and the proposal of <i>Nanosynbacteraceae</i> fam. nov., <i>Nanosynbacterales</i> ord. nov. and <i>Nanosynbacteria</i> class nov.","authors":"Erik L Hendrickson, Batbileg Bor, Xuesong He, Jeffrey S McLean","doi":"10.1099/ijsem.0.007162","DOIUrl":"10.1099/ijsem.0.007162","url":null,"abstract":"<p><p>The recently validly published phylum <i>Minisyncoccota</i> (previously <i>Ca</i>. Patescibacteriota or candidate phyla radiation) had long been an enigma, with members having remained uncultivated for several decades since the first SSU ribosomal sequence was recovered. We reported on the first isolated strain of <i>Minisyncoccota</i>, <i>Nanosynbacter lyticus</i> type strain TM7x^T (ATCC TSD-290^T), in 2015, using directed cultivation from human oral samples. Strain TM7x^T had an extremely reduced genome (705 CDS), ultra-small cell size (200-300 nm), and replicated as an obligate epibiont on the surface of another commonly found oral species: <i>Pauljensenia odontolytica_C</i> strain XH001 (host bacterium). TM7x^T also exhibited what has been defined as a parasitic phase, where it disrupts the membrane of the bacterial host cell, resulting in host bacteria lysis. However, free-floating, host-free TM7x^T cells remain viable and can re-infect fresh host bacterial cells when available. This discovery and coculture marked the first concrete evidence of how these ultrasmall organisms within the <i>Minisyncoccota</i> survive and persist despite their reduced genomes missing <i>de novo</i> biosynthesis of many essential compounds, including all amino acids and vitamins. This model dual species system has now allowed a deeper understanding of the TM7x-host bacterium interaction and dynamics, with over 15 publications reporting on various aspects of this strain to date. We propose the name <i>Nanosynbacter lyticus</i> gen. nov. sp. nov. for strain TM7x^T. We also propose <i>Nanosynbacteraceae</i> fam. nov., <i>Nanosynbacterales</i> ord. nov. and <i>Nanosynbacteria</i> class nov. to accommodate the genus <i>Nanosynbacter</i>.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Banningia</i> (<i>Saccotheciaceae</i>, <i>Dothideales</i>) re-examined: morphological clarification of <i>Banningia maryelizabethiae</i> and introduction of <i>Banningia arbuti</i> sp. nov.","authors":"Joana Domingues, Célia Soares, Carla Santos, Cristina Pintado, Nelson Lima, João Trovão","doi":"10.1099/ijsem.0.007169","DOIUrl":"10.1099/ijsem.0.007169","url":null,"abstract":"<p><p>The family <i>Saccotheciaceae</i> (<i>Dothideales</i>) encompasses a diverse fungal group displaying a wide ecological plasticity and morphological diversity. During a study focusing on the microbiological evaluation of <i>Arbutus unedo</i> fruits from Portugal, an unknown <i>Saccotheciaceae</i> isolate was retrieved, for which achieving a consensus identification proved to be challenging. Preliminary molecular analysis pointed to a close relationship with <i>Banningia maryelizabethiae</i>, a genus and species for which the original description lacked detailed morphological traits. The aim of this work was thus to understand the taxonomic status of this isolate through an integrative polyphasic approach. In parallel, the ex-type strain of <i>B. maryelizabethiae</i> was also re-examined, allowing its first comprehensive morphological characterization and enabling an emended circumscription of the genus. Phylogenetic analyses based on concatenated internal transcribed spacer and LSU ribosomal rDNA gene fragments placed the recovered strain in a well-supported lineage sister to <i>B. maryelizabethiae</i> within <i>Saccotheciaceae</i>. Further comparative morphological examinations, MALDI-TOF MS profiles and biogeographical and ecological data also demonstrated a clear differentiation between both taxa. These results supported the introduction of a novel species, <i>Banningia arbuti</i> sp. nov., while also providing amended descriptions for both the genus <i>Banningia</i> and <i>B. maryelizabethiae</i>. Moreover, this work also contributes to improved taxonomic resolution within the phylogenetically complex <i>Saccotheciaceae</i> family.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"76 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147929662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}