International journal of systematic and evolutionary microbiology最新文献

{"title":"Erratum: <i>Metschnikowia ratanii</i> f.a. sp. nov., an ascomycetous yeast species isolated from flowers of Lantana camara in India.","authors":"Rameshwar Avchar, Ana Pontes, Marc-André Lachance, Avinash Sharma, José Paulo Sampaio","doi":"10.1099/ijsem.0.006889","DOIUrl":"10.1099/ijsem.0.006889","url":null,"abstract":"","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816614","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":"Expanding species diversity in the monotypic genera <i>Thalassoporum</i> and <i>Tumidithrix</i> (<i>Pseudanabaenales</i>, <i>Cyanobacteriota</i>) with the description of <i>Thalassoporum mexicanum</i> sp. nov. and <i>Tumidithrix helvetica</i> sp. nov.","authors":"Aniket Saraf, Boris Aleksovski, Eddy Blondet, Svetislav Krstić, Alexis Criscuolo, Muriel Gugger","doi":"10.1099/ijsem.0.006869","DOIUrl":"10.1099/ijsem.0.006869","url":null,"abstract":"<p><p>The taxonomic identity of two well-documented pseudanabaenalean strains, <i>Pseudanabaena</i> sp. PCC 7367^T and <i>Pseudanabaena</i> sp. PCC 7403^T, isolated from the samples collected from the surface of a snail shell in an intertidal zone and sphagnum bog, respectively, was reassessed using a polyphasic approach. The results from the morphological, phylogenetic, ITS rRNA and genomic analyses confirmed that PCC 7367^T (=BACA0810^T) and PCC 7403^T (=BACA0811^T) represent novel species of the monotypic pseudanabaenalean genera <i>Thalassoporum</i> and <i>Tumidithrix</i>, respectively, for which we propose the names <i>Thalassoporum mexicanum</i> sp. nov. and <i>Tumidithrix helvetica</i> sp. nov. in accordance with the International Code of Nomenclature of Prokaryotes. The analysis of the 16S-23S ITS rRNA region, a widely used genetic marker for the delineation of closely related species, effectively distinguished the <i>Thalassoporum</i> species. However, the closely related species within <i>Tumidithrix</i> could not be demarcated using the currently accepted nucleotide dissimilarity cutoff for species delineation but were clearly distinguished through genomic analyses. Accordingly, a revised ITS rRNA nucleotide dissimilarity cutoff is proposed for species delineation within the genus <i>Tumidithrix</i>. Furthermore, genomic investigations revealed that the predicted biosynthetic gene clusters in the genome assemblies of PCC 7367^T and PCC 7403^T were not associated with any known natural products.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144882879","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>Leisingera coralii</i> sp. nov., a bacterium isolated from seawater surrounding <i>Acropora digitata</i>.","authors":"Xiangrui Guo, Jing Sun, Zhen Yu, Xuerui Liu, Min Li, Shangqing Zhang, Wei Wang, Xiaolei Wang, Yanying Zhang, Hao Sun","doi":"10.1099/ijsem.0.006896","DOIUrl":"https://doi.org/10.1099/ijsem.0.006896","url":null,"abstract":"<p><p>Coral reefs are experiencing significant degradation, largely driven by rising seawater temperatures. The bacterial communities within coral holobionts play crucial roles that support coral reef conservation and restoration, offering potential solutions to mitigate the impacts of environmental stressors. A Gram-negative bacterium, designated strain D0M16^T, was isolated from seawater surrounding <i>Acropora digitata</i> coral in Daya Bay, Shenzhen, Guangdong Province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed the closest relatives to be <i>Cribrihabitans neustonicus</i> JCM 19537^T (97.40%) and <i>Leisingera thetidis</i> KCTC 92110^T (97.04%). Phylogenomic analysis showed that the strain D0M16^T represents a novel species within the genus <i>Leisingera</i>. Cell growth occurred at 20-45 °C temperature, 0-9% (w/v) NaCl concentration and pH 6.0-8.0, with optimum conditions at 28-37 °C temperature, 1% (w/v) NaCl concentration and pH 7.0. Chemotaxonomic characterization identified summed feature 8 as the predominant fatty acid (67.6%), with ubiquinone-10 as the major respiratory quinone. The genome size was 4.77 Mb, with a DNA G+C content of 64.0 mol%. Comparative genomic analysis revealed that the average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between D0M16^T and <i>L. thetidis</i> KCTC 92110^T were 88.2%, 89.4% and 53.4%, respectively, and those values of 90.4%, 92.8% and 38.7% between D0M16^T and <i>Leisingera caerulea</i> DSM 24564^T, respectively. The phylogenomic tree further confirmed the distinct taxonomic position of D0M16^T relative to these closely related species. Based on comprehensive phylogenomic, phenotypic and chemotaxonomic characteristics, strain D0M16^T represents a novel species of the genus <i>Leisingera</i>, for which the name <i>Leisingera coralii</i> sp. nov. is proposed. The type strain is D0M16^T (=MCCC 1K09457^T=KCTC 18159^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144954112","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":"Description of <i>Streptomyces soliscabiei</i> sp. nov. and <i>Streptomyces echiniscabiei</i> sp. nov., which cause common scab disease on <i>Solanum tuberosum</i>.","authors":"Brett A Shelley, Christopher R Clarke","doi":"10.1099/ijsem.0.006880","DOIUrl":"https://doi.org/10.1099/ijsem.0.006880","url":null,"abstract":"<p><p>Recent genome sequencing of phytopathogenic <i>Streptomyces</i> strains has revealed previously unknown diversity of species able to cause common scab disease on potato and other root or tuber crops. Here, <i>Streptomyces</i> strain NY05-11A^T is described as the type strain for <i>Streptomyces soliscabiei</i> sp. nov., and <i>Streptomyces</i> strain WI04-05B^T is described as the type strain for <i>Streptomyces echiniscabiei</i> sp. nov. using polyphasic taxonomy including phylogenetics based on multilocus sequence analysis, whole-genome average nt identity and phenotypic characterization of morphological and biochemical traits. Both <i>Streptomyces</i> spp. strains NY05-11A^T and WI04-05B^T were confirmed to cause common scab on potato.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144954123","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>Melissospora conviva</i> gen. nov., sp. nov., a novel actinobacterial genus isolated from beehive through cross-feeding interactions.","authors":"Déborah Tellatin, Luc Cornet, Valdes Snauwaert, Philippe Compère, Marc Ongena, Loïc Quinton, Nudzejma Stulanovic, Silvia Ribeiro Monteiro, Augustin Rigolet, Pierre Burguet, Petra Van Damme, Lorena Carro, Sébastien Rigali","doi":"10.1099/ijsem.0.006868","DOIUrl":"10.1099/ijsem.0.006868","url":null,"abstract":"<p><p>Most micro-organisms remain unculturable under standard laboratory conditions, limiting our understanding of microbial diversity and ecological interactions. One major cause of this uncultivability is the loss of access to essential cross-fed metabolites when bacteria are removed from their natural communities. During a bioprospecting campaign targeting actinomycetes of an <i>Apis mellifera</i> beehive, we identified five isolates (DT32, DT45^T, DT55, DT59 and DT194) that required co-cultivation for growth recovery, suggesting a dependence on microbial interactions in their native habitat. Whole-genome sequencing and phylogenetic analysis positioned these isolates within a distinct lineage of <i>Micromonosporaceae</i>, separate from the five officially recognized clades of the <i>Micromonospora</i> genus. A combination of microscopic, chemotaxonomic and physiological characterizations further supported their uniqueness. Notably, they exhibited high auxotrophy, being unable to use all carbon sources tested, likely due to genome reduction (4.6 Mbp) compared to other <i>Micromonosporaceae</i>. Pangenomic comparisons with their closest <i>Micromonospora</i> relatives revealed gene losses in key metabolic pathways, including the glyoxylate bypass and the Entner-Doudoroff pathway, which may explain their metabolic reliance. These findings reveal a highly specialized, ecologically adapted lineage with deep evolutionary divergence and further support microbial interdependence isolation strategies to explore the microbial dark matter. We propose <i>Melissospora conviva</i> as a novel genus and species within the <i>Actinomycetota</i> phylum, with isolate DT45^T as the representative type species and type strain, which has been deposited in public collections under the accession numbers DSM 117791 and LMG 33580.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12451618/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816601","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>Pseudoalteromonas pernae</i> sp. nov., a novel bacterium with antimicrobial potential isolated from the intestinal tract of mussel genus <i>Perna</i> (Bivalvia: Mytilidae).","authors":"Suyun Fang, Xingyue Lin, Jun Min, Yan Li, Kim Lee Chang, Xiaoke Hu","doi":"10.1099/ijsem.0.006864","DOIUrl":"https://doi.org/10.1099/ijsem.0.006864","url":null,"abstract":"<p><p>The two bacterial strains, designated YIC-656^T and YIC-468, were isolated from the intestinal tract of <i>Perna</i> mussels (Bivalvia: Mytilidae) in China. Both strains were Gram-negative, aerobic, rod-shaped and motile, with a single polar flagellum. Strain YIC-656^T exhibited the highest 16S rRNA gene sequence similarity (98.4%) to strain <i>Pseudoalteromonas ruthenica</i> KMM300^T, followed by <i>Pseudoalteromonas caenipelagi</i> JBTF-M23^T and <i>Pseudoalteromonas xishaensis</i> E418^T, with sequence similarities of 98.3% and 98.2%, respectively. The 16S rRNA gene sequence similarity between strains YIC-656^T and YIC-468 was 99.9%, and their DNA G+C contents were both 45.3%. By genomic analyses, the average nucleotide identity and digital DNA-DNA hybridization values of strain YIC-656^T with any other related species were below 74.3% and 21.8%, while the indices between YIC-656^T and YIC-468 were 98.8% and 91.3%, respectively. These results indicate that strains YIC-656^T and YIC-468 belong to the same species and are distinct from other species within the genus <i>Pseudoalteromonas</i>. Phenotypic and chemotaxonomic tests further validated their differentiation from the closest relatives. The fatty acid profiles of both strains mainly (>7.0%) consisted of C_16:0, summed feature 3 (comprising C_16:1 <i> </i>ω<i>7c</i> and/or C_16:1 <i> </i>ω<i>6c</i>), summed feature 8 (comprising C_18:1 <i> </i>ω<i>7c</i> and/or C_18:1 <i> ω</i>6<i>c</i>) and C_18:0. The predominant respiratory quinone was Q-8. The polar lipids included phosphatidylethanolamine and unidentified lipids. Based on these phenotypic and genotypic results, strains YIC-656^T and YIC-468 represent a new species of <i>Pseudoalteromonas</i>, for which we propose <i>Pseudoalteromonas pernae</i> sp. nov. The type strain is YIC-656^T (=MCCC 1K08806^T=KCTC 8211^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764879","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":"International Committee on Systematics of Prokaryotes subcommittee on the taxonomy of <i>Borrelia</i>: minutes of the first meeting. Online Zoom meeting, 13 November 2023.","authors":"Brian Stevenson, Gabriele Margos","doi":"10.1099/ijsem.0.006872","DOIUrl":"https://doi.org/10.1099/ijsem.0.006872","url":null,"abstract":"<p><p>International Committee on Systematics of Prokaryotes subcommittee on the taxonomy of <i>Borrelia</i>: minutes of the first meeting. Online Zoom meeting, 13 November 2023.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144835066","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>Variovorax arabinosiphilus</i> sp. nov., <i>Variovorax flavidus</i> sp. nov., <i>Variovorax gracilis</i> sp. nov., <i>Variovorax brevis</i> sp. nov., <i>Variovorax jilinensis</i> sp. nov., <i>Variovorax davisae</i> sp. nov., <i>Variovorax saccharolyticus</i> sp. nov. and <i>Variovorax fucosicus</i> sp. nov., isolated from ginseng rhizosphere.","authors":"Yu-Hang Jiang, Ce-Ce Yin, Lei-Lei Yang, Yu-Hua Xin, Qing Liu, Jian Ye","doi":"10.1099/ijsem.0.006895","DOIUrl":"https://doi.org/10.1099/ijsem.0.006895","url":null,"abstract":"<p><p>Thirteen novel strains - J2L1-78^T, J2P1-59^T, J22R24^T, J22R133^T, J22P168^T, J22P271^T, J22R187^T, J22R193^T, J2L1-63, J2R1-6, J22G21, J22G47, and J31P216 - were isolated from the rhizosphere of 20-year-old ginseng in Jilin Province, P.R. China. These strains were Gram-stain-negative, aerobic and rod-shaped. Phylogenetic analysis based on the 16S rRNA gene sequences indicated their affiliation to the genus <i>Variovorax</i>, with 98.8-99.6% sequence similarity to <i>Variovorax ginsengisoli</i> Gsoil 3165^T, <i>Variovorax ureilyticus</i> UCM-2^T and <i>Variovorax humicola</i> UC38^T. Phylogenomic analysis demonstrated their distinctiveness from closely related species. Average nucleotide identity (ANI) values among these strains confirm their representation of eight distinct species; additionally, ANI and digital DNA-DNA hybridization values between these strains and their closest relatives were below 92.5 and 54.1%, respectively. Eight representative strains contained C_16 : 0, summed feature 3 (C_16 : 1 <i> ω</i>7<i>c</i> and/or C_16 : 1 <i> ω</i>6<i>c</i>) and C_17 : 0 cyclo as major fatty acids. Based on phenotypic, phylogenetic and genotypic data, these 13 strains comprise 8 novel species within the genus <i>Variovorax</i>, for which we propose the following names: <i>Variovorax arabinosiphilus</i> sp. nov. (J2L1-78^T=CGMCC 1.60704^T=KACC 23365^T), <i>Variovorax flavidus</i> sp. nov. (J2P1-59^T=CGMCC 1.60707^T=KACC 23366^T), <i>Variovorax gracilis</i> sp. nov. (J22R24^T=CGMCC 1.61001^T=KACC 23367^T), <i>Variovorax brevis</i> sp. nov. (J22R133^T=CGMCC 1.61263^T=KACC 23368^T), <i>Variovorax jilinensis</i> sp. nov. (J22P168^T=CGMCC 1.64555^T=KACC 23372^T), <i>Variovorax davisae</i> sp. nov. (J22P271^T=CGMCC 1.64593^T=KACC 23373^T), <i>Variovorax saccharolyticus</i> sp. nov. (J22R187^T=CGMCC 1.64629^T=KACC 23374^T) and <i>Variovorax fucosicus</i> sp. nov. (J22R193^T=CGMCC 1.64631^T=KACC 23375^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12396923/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144954130","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":"Characterization of <i>Phyllobacterium</i> spp. isolated from root nodules of <i>Melilotus albus</i> (white sweet clover) grown in Canada and description of <i>Phyllobacterium meliloti</i> sp. nov.","authors":"Eden S P Bromfield, Sylvie Cloutier, Michael F Hynes","doi":"10.1099/ijsem.0.006876","DOIUrl":"10.1099/ijsem.0.006876","url":null,"abstract":"<p><p>Two novel bacterial strains isolated from root nodules of white sweet clover (<i>Melilotus albus</i>) plants grown at a Canadian site were previously characterized and placed in the genus <i>Phyllobacterium</i>. Here, we present phylogenomic and phenotypic data to support the description of strain T1293^T as representative of a novel species and present the first complete closed genome sequence of a bacterial strain (T1018) representing the species '<i>Phyllobacterium pellucidum</i>'. Phylogenetic analysis of genome sequences, as well as analysis of 53 core genes, placed novel strain T1293^T in a highly supported cluster of strains distinct from named <i>Phyllobacterium</i> species with <i>Phyllobacterium myrsinacearum</i> and <i>Phyllobacterium calauticae</i> as closest relatives. The highest average nucleotide identity and digital DNA-DNA hybridization values of genome sequences of T1293^T compared to closest species type strains (84.1 and 26.5%, respectively) are well below the threshold values for bacterial species circumscription. The genome of strain T1293^T has a size of 5,074,034 bp with a DNA G+C content of 55.1 mol% and possesses three plasmids with sizes of 397,619 bp, 476,847 bp and 519,835 bp. Detected in the genome were type III and type VI secretion system genes, implicated in plant-microbe and microbe-microbe interactions, but key nodulation, nitrogen-fixation and photosystem genes were not detected. A novel prophage (size ~41.5 kb) was also detected in the genome of T1293^T. Tests using defined culture media revealed that novel strains T1293^T and T1018 were highly resistant to, and able to metabolize glyphosate, a widely used herbicide that has negative consequences for the environment and human health. Data for multiple morphological, physiological, biochemical and plant tests complemented the sequence-based data. The data presented support the description of a new species, and the name <i>Phyllobacterium meliloti</i> sp. nov. is proposed with T1293^T=LMG 32641^T=HAMBI 3765^T as the species type strain.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12451606/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144794400","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>Cedecea selenatireducens</i> sp. nov. and <i>Rahnella selenatireducens</i> sp. nov., isolated from the seleniferous soil.","authors":"Sasa Zhang, Yi Liu, Haoyang Wang, Jing Peng, Kui Li, Ziwei Jiao, Yanbin Guo","doi":"10.1099/ijsem.0.006885","DOIUrl":"https://doi.org/10.1099/ijsem.0.006885","url":null,"abstract":"<p><p>Two Gram-stain-negative bacterial strains, designated S5-13^T and S5-11^T, were isolated from seleniferous soil in Enshi, PR China. Both strains demonstrated the ability to tolerate high concentrations of selenite and selenate and efficiently reduced these selenium oxyanions to elemental selenium. Phylogenetic and phylogenomic analyses revealed that strain S5-13^T belongs to the genus <i>Cedecea</i>, while S5-11^T is affiliated with the genus <i>Rahnella</i>. Strain S5-13^T (genome size, 4.77 Mb; G+C content, 55.1 mol%) exhibited the closest relationship to <i>Cedecea neteri</i> ATCC 33855^T with an average nucleotide identity (ANI) value of 91.4% and a digital DNA-DNA hybridization (dDDH) value of 46.2%. Additionally, phylogenomic analyses identified strain SSMD04 from the GenBank database as clustering within the genus <i>Cedecea</i> alongside strain S5-13^T. The ANI and dDDH values between strains S5-13^T and SSMD04 were 99.2% and 93.8 %, respectively, confirming their classification as the same species. Strain S5-11^T (genome size, 5.45 Mb; G+C content, 52.4 mol%) showed the closest phylogenetic affinity to <i>Rahnella laticis</i> SAP-17^T and <i>Rahnella contaminans</i> Lac-M11^T, with ANI values of 94.4% and 92.7 %, respectively. S5-13^T and S5-11^T contained C_16:0 and C_17:0 cyclo as the dominant fatty acids. Phenotypic characteristics further distinguished strains S5-13^T and S5-11^T from their closest relatives. Based on these results, strain S5-13^T and S5-11^T represent novel species within the genera <i>Cedecea and Rahnella</i>, for which the names <i>Cedecea selenatireducens</i> sp. nov. (type strain S5-13^T=GDMCC 1.4366^T=JCM 37117^T) and <i>Rahnella selenatireducens</i> sp. nov. (type strain S5-11^T=GDMCC 1.4365^T=JCM 37116^T) are proposed.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 8","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816600","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}