Systematic and applied microbiology最新文献

{"title":"Magnetovirga frankeli gen. Nov., sp. nov., a magnetotactic bacterium isolated from the Salton Sea, California, that represents a novel lineage in the Gammaprotoeobacteria","authors":"Mila Sirinelli-Kojadinovic ,&nbsp;Elsa C.A. Turrini ,&nbsp;Emma Ropion ,&nbsp;Béatrice Alonso ,&nbsp;Marine Bergot ,&nbsp;Emilie Gachon ,&nbsp;Philippe Ortet ,&nbsp;Paul E.D. Soto-Rodriguez ,&nbsp;Caroline L. Monteil ,&nbsp;Christopher T. Lefevre","doi":"10.1016/j.syapm.2025.126621","DOIUrl":"10.1016/j.syapm.2025.126621","url":null,"abstract":"<div><div>A magnetotactic bacterium, designated strain SS-5^T, was isolated from the Salton Sea, a highly saline lake in California, USA, and cultivated in axenic culture. The Gram-negative cells of strain SS-5^T are relatively small and rod-shaped and possess a single polar flagellum (monotrichous). This strain is a magnetotactic bacterium producing magnetite nanocrystals aligned in one chain per cell. Strain SS-5^T is a microaerophile that grows chemolithoautotrophically while reducing oxygen as a terminal electron acceptor. Optimal growth occurred at pH 7.0–7.3 and 28–36 °C with thiosulfate used as an electron donor and sodium bicarbonate as a carbon source. Based on its genome sequence, the G + C content is 61.6 %. Phylogenomic and phylogenetic analyses indicate that strain SS-5^T belongs to the <em>Sedimenticolaceae</em> family within the <em>Gammaproteobacteria</em> class. Based on average amino acid identity, strain SS-5^T can be considered as a novel species of a new genus, for which the name <em>Magnetovirga frankeli</em> is proposed. The type strain of <em>M. frankeli</em> is SS-5^T (=DSM 116211^T = JCM 39467^T).</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126621"},"PeriodicalIF":3.3,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macrococcus capreoli sp. nov., a new fosfomycin resistant species isolated from feces and nasal swabs of deer","authors":"Carolin J. Schiffer ,&nbsp;Matthias A. Ehrmann","doi":"10.1016/j.syapm.2025.126620","DOIUrl":"10.1016/j.syapm.2025.126620","url":null,"abstract":"<div><div>Five strains of Gram-stain-positive, non-motile, and coccoid-shaped bacteria, designated as TMW 2.2395^T, TMW 2.2628, TMW 2.2670, TMW 2.2756 and TMW 2.2757 were isolated from feces and nasal mucosa of wild living roe deer (<em>Capreolus capreolus</em>) and red deer (<em>Cervus elaphus</em>), respectively. The isolates share identical 16S rRNA gene sequences and are classified within the genus <em>Macrococcus</em> based on 16S and MALDI-TOF MS analyses. Phylogenetic analysis revealed that average nucleotide identity (ANI) values were below the accepted thresholds for prokaryotic species delineation, with the type strains of <em>M. goetzii</em>, <em>M. bohemicu</em><em>s</em> and <em>M. epidermidis</em> showing the highest relatedness values (79.59 %, 79.30 % and 79.52 %, respectively). Digital DNA–DNA hybridization (dDDH) values were below 23 % confirming that all five strains belong to a new species within the genus <em>Macrococcus</em>. All strains were catalase and oxidase positive, grew optimally at 37 °C and pH 7.0, but demonstrated considerably lower salt tolerance (&lt; 7.5 % <em>w</em><em>/</em><em>v</em> nit iterativ) compared to other species in the genus. Moreover, the data of this study suggests that members of this new species possess an intrinsic resistance to fosfomycin, putatively mediated by a <em>fosB</em> homologue. The genomes range from 2.4 and 2.5 Mb in size, with a G+C content of 34.8 to 35.1 %. The primary respiratory quinone of the type strain TMW 2.2395^T is Menaquinone 6 (MK-6, 98.6 %), the cell wall peptidoglycan type is A3α L-Lys-Gly₃-L-Ser and the major fatty acids are C_14:0, C_16:0 and C_18:0. Phylogenetic, phenotypic and chemotaxonomic data collectively suggest that these strains represent a novel species of the genus <em>Macrococcus</em>, for which the name <em>Macrococcus capreoli</em> sp. nov. is proposed. The type strain is TMW 2.2395^T = DSM 113939^T = LMG 32618^T.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126620"},"PeriodicalIF":3.3,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the hidden microbiome: a microbiological exploration of untouched burial crypts in Krakow, Poland","authors":"Patrycja Tarnawska ,&nbsp;Aleksandra Burkowska-But ,&nbsp;Maria Swiontek Brzezińska ,&nbsp;Anna Drążkowska ,&nbsp;Adriana Osińska ,&nbsp;Maciej Walczak","doi":"10.1016/j.syapm.2025.126618","DOIUrl":"10.1016/j.syapm.2025.126618","url":null,"abstract":"<div><div>Cultural heritage objects provide valuable historical information, but can also harbour biological threats. Still, little is said about the potential risks that may await unaware researchers, conservators, and archaeologists. Our work discusses the study results from the crypts in Krakow, which were opened for the first time. The human and coffin remains were examined. The number of actinomycetes, other mesophilic bacteria, bacterial spores, and xerophilic and non-xerophilic fungi was determined. In general, a low number of microbes was observed. However, scanning electron microscope (SEM) images showed many bacterial conglomerates and confirmed that microbial activity affected the fibres covering cadavers in the crypts. The most abundant were mesophilic bacteria, followed by bacterial spores and actinomycetes. They reached up to 10⁷ CFU/g in fabric remains, 5.2 × 10⁶ CFU/g in burial remains, and 1.6 × 10⁶ CFU/g found under the coffin, and above 7.5 × 10⁵ CFU/g for xerophilic and non-xerophilic fungi. NGS (Next-Generation Sequencing) results suggested that the low presence of microorganisms may be due to the dominance of unculturable or long-growing bacteria belonging to <em>Mycobacterium</em>, such as <em>M. coloregonium</em>, <em>M. arupense</em>, and <em>M. pinnipedii.</em> Moreover, other obligatory/non-obligatory pathogens, <em>Bacteroides fragilis, Clostridium botulinum, Coxiella burnetii</em>, <em>Clostridium tetani</em>, <em>Corynebacterium diphtheriae</em>, <em>Enterobacter cloacae</em>, <em>Escherichia coli</em>, <em>Legionella pneumophila</em>, <em>Mycobacterium leprae</em>, <em>Rhodococcus equi</em>, and <em>Staphylococcus aureus</em> have been recorded in examined samples, with the dominance in bone samples. Results indicate the risk of dangerous pathogens present in historical objects, the impact on health may be severe, and the need to use personal protective equipment and proper measures to control the physical conditions of crypts.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126618"},"PeriodicalIF":3.3,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhizobium binxianense sp. nov. and Rhizobium mulingense sp. nov., isolated from nodules of Phaseolus vulgaris in Heilongjiang Province of China","authors":"Yuxi Liu ,&nbsp;Lili Liu ,&nbsp;Ziqi Wang ,&nbsp;Xiaoqian Huang ,&nbsp;Yuxin Dong ,&nbsp;Dong Hu ,&nbsp;Chuntao Gu ,&nbsp;En Tao Wang ,&nbsp;Hao Wang","doi":"10.1016/j.syapm.2025.126619","DOIUrl":"10.1016/j.syapm.2025.126619","url":null,"abstract":"<div><div>Rhizobial isolates from <em>Phaseolus vulgaris</em> (common bean) grown in Heilongjiang Province were grouped into two clusters based upon the phylogenies of 16S rRNA and <em>recA-atpD</em> genes representing by BJ04^T, MJ22, MJ37, BC56, MC62 and MC63^T, MJ21, MJ31, respectively. The phylogenetic analysis of whole genomes further revealed that BJ04^T, MJ22, MJ37, BC56 and MC62 formed a cluster neighbored <em>Rhizobium chutanense</em> C5^T, while MC63^T, MJ21 and MJ31 formed a cluster most related with <em>Rhizobium croatiense</em> 13T^T. The whole genome average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the strains BJ04^T and <em>R. chutanense</em> C5^T and between MC63^T and <em>R. croatiense</em> 13T^T were lower than the species thresholds 95 % and 70 %, respectively. While the G + C content of the whole genome of the novel strains were 61.16–61.56 %, within the allowable GC content range of the <em>Rhizobium</em> genus (57–66 %). These results, combined with chemical classification and phenotype analysis, supported that BJ04^T and MC63^T represented two novel species and the names <em>Rhizobium binxianense</em> sp. nov. and <em>Rhizobium mulingense</em> sp. nov. were described for them. BJ04^T (=CCTCC AB 2022367^T, = JCM 35885^T) and MC63^T (=CCTCC AB 2024025^T, = JCM 36652^T) were designed as the type strains, respectively for these two novel species.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126619"},"PeriodicalIF":3.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N-glyceroyl alkylamine phosphoglycolipids dominate the lipidome of several Bacillota bacteria","authors":"Nicole J. Bale ,&nbsp;Michel Koenen ,&nbsp;Su Ding ,&nbsp;Jaap S. Sinninghe Damsté","doi":"10.1016/j.syapm.2025.126609","DOIUrl":"10.1016/j.syapm.2025.126609","url":null,"abstract":"<div><div>Elucidation of the membrane lipid composition of bacteria can help to better understand how bacterial cells interact with their surroundings, adapt to environmental stress, and resist antimicrobial agents. Here we describe for the first time the detection of a wide array of N-glyceroyl alkylamine phosphoglycolipids (NGAPs) in a range of <em>Bacillota</em> bacteria (formerly <em>Firmicutes</em>). <em>Bacillota</em> includes a diverse range of bacteria that are typically highly resistant to harsh conditions such as heat, radiation, and pH, allowing the bacteria to survive in unfavorable environments. In 9 out 18 investigated strains of <em>Bacillota</em>, spread across 5 orders (<em>Thermoanaerobacterales, Thermosediminibacterales, Eubacteriales, Halanaerobiales</em>, and <em>Sulfobacillia</em>) mild acid hydrolysis released N-glyceroyl alkylamines (NGAs), which were detectable by gas chromatography–mass spectrometry (GC–MS) during routine fatty acid analysis. One strain, <em>Moorella thermoacetica</em> was found to produce long-chain NGAs (C₃₀-C₃₂), which are postulated to have <em>iso</em>diabolic acid-like structures. A wide variety of intact polar NGAPs were identified using ultra-high pressure liquid chromatography high resolution multi-stage mass spectrometry (UHPLC-HRMSⁿ). These include many previously undescribed lipids with a variety of sugar moieties and glycerol-bound core lipid moieties, including ether-bound components and alkyl 1,2-diols. The NGAPs constituted the majority of the intact polar lipid composition of these strains and presumably contribute to their tough cell membranes. The presence of NGAs in <em>Bacillota</em> appears to be associated with thermophilia. Both the hydrolysis-derived NGAs and intact polar NGAPs have potential to be biomarkers for extremophilic and, in particular, thermophilic bacteria.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126609"},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to: “Flavobacterium plantiphilum sp. nov., Flavobacterium rhizophilum sp. nov., Flavobacterium rhizosphaerae sp. nov., Chryseobacterium terrae sp. nov., and Sphingomonas plantiphila sp. nov. isolated from salty soil showing plant growth promoting potential” [Systematic and Applied Microbiology 48 (2025) 126588]","authors":"Peter Kämpfer ,&nbsp;André Lipski ,&nbsp;Kathy S. Lawrence ,&nbsp;Walker R. Olive ,&nbsp;Molli M. Newman ,&nbsp;John A. McInroy ,&nbsp;Tomeu Viver","doi":"10.1016/j.syapm.2025.126603","DOIUrl":"10.1016/j.syapm.2025.126603","url":null,"abstract":"","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 3","pages":"Article 126603"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “Characterization of two novel species of the genusBifidobacterium: Bifidobacterium saimiriisciurei sp. nov. and Bifidobacterium platyrrhinorum sp. nov.” [Syst. Appl. Microbiol. 43 (2020) 126111]","authors":"Monica Modesto ,&nbsp;Maria Satti ,&nbsp;Koichi Watanabe ,&nbsp;Donatella Scarafile ,&nbsp;Chien-Hsun Huang ,&nbsp;Jong-Shian Liou ,&nbsp;Tomohiko Tamura ,&nbsp;Satomi Saito ,&nbsp;Mizuki Watanabe ,&nbsp;Koji Mori ,&nbsp;Lina Huang ,&nbsp;Camillo Sandri ,&nbsp;Caterina Spiezio ,&nbsp;Masanori Arita ,&nbsp;Paola Mattarelli","doi":"10.1016/j.syapm.2025.126601","DOIUrl":"10.1016/j.syapm.2025.126601","url":null,"abstract":"","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 3","pages":"Article 126601"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natronomicrosphaera hydrolytica, gen. nov., sp. nov., a first representative of the phylum Planctomycetota from soda lakes","authors":"Dimitry Y. Sorokin ,&nbsp;Alexander Y. Merkel ,&nbsp;Nicole J. Bale ,&nbsp;Michel Koenen ,&nbsp;Jaap S. Sinninghe Damsté ,&nbsp;Laura Marturano ,&nbsp;Enzo Messina ,&nbsp;Violetta La Cono ,&nbsp;Michail M. Yakimov","doi":"10.1016/j.syapm.2025.126608","DOIUrl":"10.1016/j.syapm.2025.126608","url":null,"abstract":"<div><div>Despite intensive microbiological characterization of soda lake microbial communities, no culturable representatives from the phylum <em>Planctomycetota</em> have been isolated from these haloalkaline habitats. In the context of studying polysaccharide utilization by soda lake microbial communities, we used polysaccharide hyaluronic acid as enrichment substrate at aerobic, moderate haloalkaline conditions (1 M total Na⁺, pH 9.5). This resulted in a selective enrichment and isolation in pure culture of a bacterial strain AB-hyl4 belonging to <em>Planctomycetota</em>. The cells are tiny motile cocci growing in large aggregates, with the Gram-negative type of ultrastructure and producing a yellow pigment. This obligate aerobic saccharolytic heterotroph has an extremely narrow growth substrate range including, besides hyaluronic acid, melezitose and glycerol. The membrane lipids consist of phosphatidylcholine and two types of neutral lipids, including hopanoids and monounsaturated C17 and C19 hydrocarbons. Phylogenomic analysis placed the isolate into the family <em>Phycisphaeraceae</em>, class <em>Phycisphaerae,</em> as a new genus-level lineage. Its genome contained a gene encoding a polysaccharide lyase from the PL8 family which is probably responsible for the degradation of hyaluronic acid to a dimer, followed by its transport and hydrolysis into monomers in periplasm and final glycolytic degradation in cytoplasm. On the basis of distinct phenotypic and genomic properties, strain AB-hyl4^T (DSM 117794 = UQM 41914) is proposed to be classified as <em>Natronomicrosphaera hydrolytica</em> gen. nov., sp. nov.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 3","pages":"Article 126608"},"PeriodicalIF":3.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Representatives of the Synergistaceae family, taxonomic description and genome sequence of Caenicola nitritireducens gen nov., sp. nov., a novel fermenting and amino-acid degrading bacterium isolated from a municipal anaerobic digester sludge","authors":"Abdelaziz El Houari ,&nbsp;Magali Ranchou-Peyruse ,&nbsp;Elisabeth Carlier ,&nbsp;Anthony Ranchou-Peyruse ,&nbsp;Agnès Hirschler-Réa ,&nbsp;Rhizlane Bennisse ,&nbsp;Radia Bouterfas ,&nbsp;James E. McDonald ,&nbsp;Rémy Guyoneaud ,&nbsp;Abdel-Illah Qatibi","doi":"10.1016/j.syapm.2025.126607","DOIUrl":"10.1016/j.syapm.2025.126607","url":null,"abstract":"<div><div>Members of the phylum <em>Synergistota</em> are important but understudied components of microbial communities during anaerobic digestion. In this study, their diversity was assessed in full-scale anaerobic digester sludge samples from Marrakesh wastewater treatment plant (Morocco), using <em>16S rRNA</em> gene community profiling, as well as targeted isolation, physiological characterization, and genome sequencing of novel <em>Synergistaceae</em> isolates<em>.</em> The <em>16S rRNA</em> gene analysis identified 23 operational taxonomic units (OTUs) belonging to the family of <em>Synergistaceae</em>, representing 8.8 % of the total microbial community. 17 of these OTUs belonged to previously uncultured taxa. A dominant OTU19, presumably a new representative of the family of <em>Synergistaceae</em> was isolated in pure culture (strain DS-S4^T) and subjected to both culture- and genome-based characterizations. Phylogenetic analysis revealed that strain DZ-S4^T was related to <em>Cloacibacillus porcorum</em> CL-84^T and <em>Cloacibacillus evryensis</em> 158^T but with low sequence similarity of 89.94 % and 88.60 %, respectively. Based on genome relatedness, including Average Nucleotide Identity (ANI) and Amino Acid Identity (AAI), strain DZ-S4^T is considered to represent a novel genus for which the name <em>Caenicola</em> gen.nov is proposed. Moreover, several phenotypic and eco-physiological properties differentiated the novel isolate from its related species, indicating that the strain represents a new species for which the name <em>Caenicola nitritireducens</em> sp. nov. is proposed, with strain DZ-S4^T (=DSM 104940^T = JCM 31897^T) being the type strain. Additionally, this study investigates the ecological role of strain DZ-S4^T, specifically the protein degradation, the bioconversion of carbohydrates, and the nitrite reduction during anaerobic digestion.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 3","pages":"Article 126607"},"PeriodicalIF":3.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative genomics of Elusimicrobiaceae (phylum Elusimicrobiota) and description of the isolates Elusimicrobium simillimum sp. nov., Elusimicrobium posterum sp. nov., and Parelusimicrobium proximum gen. nov. sp. nov.","authors":"Undine S. Mies ,&nbsp;Hao Zheng ,&nbsp;Katja Platt ,&nbsp;Renate Radek ,&nbsp;Nicole Paczia ,&nbsp;Sebastian C. Treitli ,&nbsp;Andreas Brune","doi":"10.1016/j.syapm.2025.126606","DOIUrl":"10.1016/j.syapm.2025.126606","url":null,"abstract":"<div><div>The tree of life comprises many deep-branching lineages with no or only very few cultured representatives. One such lineage is the phylum <em>Elusimicrobiota</em>, which contains only two described species and whose biology has been only poorly explored. We isolated three new species from this phylum from the intestinal tracts of cockroaches. Like their closest relative, <em>Elusimicrobium minutum</em>, the only member of the family <em>Elusimicrobiaceae</em> described to date, they are small, pleomorphic gram-negative rods characterized by a distinct cell cycle, and like all ultramicrobacteria, they pass through a 0.22-μm filter membrane. Physiological characterization of all isolates revealed that they are obligately anaerobic fermenters that lack catalase and cytochrome <em>c</em> oxidase activities but can remove oxygen from their environment in a non-respiratory manner. Their substrate range is limited to a few hexoses, such as <span>d</span>-glucose, <span>d</span>-galactose, and <em>N</em>-acetyl-<span>d</span>-glucosamine, which are fermented to lactate, acetate, ethanol, and hydrogen as major products. Comparative genome analysis, which included more than 100 MAGs of uncultured lineages of <em>Elusimicrobiaceae</em>, revealed the underlying metabolic pathways and outlined a new phylogenomic framework of the family. Based on phylogenomic, physiological, and morphological evidence, we describe the new isolates as <em>Parelusimicrobium proximum</em> gen. nov., sp. nov., <em>Elusimicrobium posterum</em> sp. nov., and <em>Elusimicrobium simillimum</em> sp. nov. under the rules of ICNP. Based on high-quality genomes of all uncultured representatives, we propose a comprehensive taxonomy of all lineages in the family under the rules of SeqCode, including the new genera <em>Avelusimicrobium</em>, <em>Proelusimicrobium</em>, and the candidate genus “<em>Pseudelusimicrobium</em>”.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 3","pages":"Article 126606"},"PeriodicalIF":3.3,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}